Zinc

Evidence-based effects and studies

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Effects
1550
Total evidences
1971

Effects and Evidences

Detailed analysis of research findings

diarrhea duration

6 evidences

Children with acute gastroenteritis received dietary advice, probiotics, zinc, or probiotics+zinc; the probiotic+zinc group recovered from diarrhea faster.

Trust comment: Prospective double-blind placebo-controlled design supports credibility, but total sample size is modest (n=132).

Study Details

PMID:36660970
Participants:132
Impact:mean 43.5 h in probiotics+zinc vs 84.5 h in control (−41.0 h; ~−48% relative)
Trust score:4/5

Randomized, double-blind, placebo-controlled trial in infants 1–6 months showing no benefit of zinc on diarrhea duration or stool volume.

Trust comment: Well-designed randomized controlled trial with adequate sample (n=275) showing null effects in young infants.

Study Details

PMID:16155274
Participants:275
Impact:no significant change
Trust score:4/5

In children treated for acute diarrhea, 5 days of zinc was as effective as 10 days at preventing subsequent diarrhea over 3 months.

Trust comment: Large randomized, community double-blind trial with daily supervision and adequate follow-up; compares two zinc regimens rather than zinc vs no zinc.

Study Details

PMID:21147907
Participants:1622
Impact:no significant difference; mean duration 3.1 ± 5.6 d (5-d) vs 2.9 ± 5.6 d (10-d) (P=0.64)
Trust score:4/5

Zinc did not reduce duration or severity of acute diarrhea in young infants.

Trust comment: Large randomized placebo-controlled trial in infants with clear outcome measures and analyses.

Study Details

PMID:16954960
Participants:1110
Impact:0.21 days longer with zinc, not statistically significant
Trust score:4/5

In hospitalized children 5–12 years with acute dehydrating diarrhea, 40 mg/day zinc for 14 days did not shorten diarrhea duration or significantly change rehydration, hospitalization time, or recurrence.

Trust comment: Randomized placebo-controlled trial with clear clinical endpoints but modest sample size and limited to hospitalized older children.

Study Details

PMID:24673165
Participants:134
Impact:no effect (median time to resolution 60 h in both zinc and placebo groups)
Trust score:4/5

Zinc supplementation (alone or with other micronutrients) given with rehydration significantly reduced duration and volume of diarrhea in young children compared with placebo.

Trust comment: Double-blind randomized placebo-controlled trial with clear clinical outcomes and reasonable sample size; combination supplements not superior to zinc alone.

Study Details

PMID:21592508
Participants:167
Impact:decreased (supplemented groups vs placebo; p<0.0001)
Trust score:4/5

diarrhea duration >5 days

1 evidences

Large multicenter RCT in children with acute diarrhea found that lower zinc doses (5 or 10 mg) were non-inferior to 20 mg for diarrhea outcomes and caused less vomiting.

Trust comment: Large, randomized, double-blind multicenter trial with high follow-up and prespecified non-inferiority margins; high confidence.

Study Details

PMID:32966722
Participants:4500
Impact:similar across arms: 6.5% (20 mg) vs 7.7% (10 mg) and 7.2% (5 mg); non-inferior
Trust score:5/5

number of loose/watery stools

1 evidences

Large multicenter RCT in children with acute diarrhea found that lower zinc doses (5 or 10 mg) were non-inferior to 20 mg for diarrhea outcomes and caused less vomiting.

Trust comment: Large, randomized, double-blind multicenter trial with high follow-up and prespecified non-inferiority margins; high confidence.

Study Details

PMID:32966722
Participants:4500
Impact:mean ~10.7 (20 mg) vs 10.9 (10 mg) and 10.8 (5 mg); non-inferior
Trust score:5/5

vomiting within 30 min of dosing

1 evidences

Large multicenter RCT in children with acute diarrhea found that lower zinc doses (5 or 10 mg) were non-inferior to 20 mg for diarrhea outcomes and caused less vomiting.

Trust comment: Large, randomized, double-blind multicenter trial with high follow-up and prespecified non-inferiority margins; high confidence.

Study Details

PMID:32966722
Participants:4500
Impact:20 mg: 19.3% vs 15.6% (10 mg, −19% RR) and 13.7% (5 mg, −29% RR)
Trust score:5/5

plasma zinc concentration

57 evidences

One-year calcium supplementation in lactating Gambian women did not change urinary magnesium excretion or iron/zinc blood markers.

Trust comment: Randomized double-blind placebo-controlled trial with complete compliance and repeated measures; directly measured zinc status though zinc was not the intervention.

Study Details

PMID:9014651
Participants:60
Impact:no significant change
Trust score:4/5

16 weeks of zinc (45 or 90 mg/day) increased circulating zinc and was associated with modest reductions in inflammatory biomarkers in ART-treated people living with HIV.

Trust comment: Phase I open-label randomized pilot (n=52); pilot size and open-label design reduce certainty though biomarker changes were observed.

Study Details

PMID:31609926
Participants:52
Impact:median increase from 73 to 91 µg/dL (low-dose) and to 100 µg/dL (high-dose)
Trust score:3/5

Large multicenter RCT in children with acute diarrhea found that lower zinc doses (5 or 10 mg) were non-inferior to 20 mg for diarrhea outcomes and caused less vomiting.

Trust comment: Large, randomized, double-blind multicenter trial with high follow-up and prespecified non-inferiority margins; high confidence.

Study Details

PMID:32966722
Participants:4500
Impact:lower in 5 mg and 10 mg arms on days 3–14 vs 20 mg, similar by day 21–30
Trust score:5/5

In young Burkinabe children, daily preventive zinc raised plasma zinc and supplemented groups had modestly lower reported diarrhea and fever but slightly less linear growth over 16 weeks.

Trust comment: Large, cluster-randomized, masked community trial with pre-specified outcomes and plausible biologic measures (pZn).

Study Details

PMID:27489011
Participants:7641
Impact:DPZS mean change +3.9 μg/dL (SE 1.3) vs TZS -0.5 and NIC -1.2 μg/dL; P=0.008
Trust score:5/5

Daily zinc (3–10 mg) for 6 months raised plasma zinc in a dose-dependent manner and reduced diarrhea incidence by ~21–42% without adverse effects on copper or iron markers.

Trust comment: Randomized, double-masked, community-based trial with adequate sample size and clear outcomes.

Study Details

PMID:18326612
Participants:631
Impact:dose-dependent increase (P < 0.001)
Trust score:5/5

In 9–17 month-old children, daily 6 mg zinc as a liquid supplement for 15 days raised plasma zinc concentration, whereas an equivalent amount provided via zinc-fortified porridge did not.

Trust comment: Randomized double-blind intervention with clear biomarker outcome and adequate sample for short-term biomarker change; short duration and no functional outcomes measured.

Study Details

PMID:21490143
Participants:137
Impact:+4.7 μg/dL mean change with supplement (ZnSuppl), vs −1.0 μg/dL control and −1.8 μg/dL ZnFort)
Trust score:4/5

Four weeks of daily zinc (9 mg) in 9–11 y girls raised blood zinc and a bone formation marker.

Trust comment: Randomized controlled trial with objective biomarker outcomes in 147 participants; short (4-week) duration limits long-term conclusions.

Study Details

PMID:26491117
Participants:147
Impact:↑ +1.8 μmol/L (zinc) vs +0.2 μmol/L (placebo); P<0.01
Trust score:4/5

Both iron alone and iron+zinc sachets treated anemia, but adding zinc lowered anemia recovery rate and did not improve zinc status or growth.

Trust comment: Controlled intervention with a sizable sample of anemic infants, though interactions between nutrients complicate interpretation.

Study Details

PMID:12672922
Participants:304
Impact:decreased significantly in both groups (P < 0.05)
Trust score:4/5

In men adopting cholesterol-lowering, high-fiber diets, zinc intake density and plasma zinc levels were maintained over 12–24 months; no adverse effect on zinc status was observed.

Trust comment: Large, long-term study within a randomized dietary trial showing stable zinc status, though it is a secondary analysis and not a zinc-supplement intervention.

Study Details

PMID:7594123
Participants:365
Impact:No meaningful change over 12–24 months; no difference by dietary assignment
Trust score:4/5

In obese adolescents on low-energy diets, plasma zinc did not change over 12 weeks; plasma zinc correlated modestly with zinc intake and protein intake, and phytate:zinc ratio indicated lower zinc bioavailability with high-carb diet.

Trust comment: Randomized dietary trial adequately measuring zinc intake/bioavailability but not a zinc supplementation trial and sample-specific to obese insulin-resistant adolescents.

Study Details

PMID:27750250
Participants:87
Impact:No change from baseline to 12 weeks
Trust score:3/5

Daily preventive zinc (7–10 mg/day) raised plasma zinc and (exploratorily) nail zinc but did not change hair zinc in young Laotian children after ~9 months.

Trust comment: Large randomized, double-blind, placebo-controlled trial with standardized sample collection and appropriate analyses; nail results exploratory due to comparator issue.

Study Details

PMID:32356207
Participants:492
Impact:PZ vs control +10.6 μg/dL (65.8 vs 55.2 μg/dL); MNP vs control +6.5 μg/dL (61.7 vs 55.2 μg/dL); prevalence of zinc deficiency reduced (75.6% → 53.9–61.9%)
Trust score:5/5

Four weeks of lipid-based nutritional supplement improved energy intake, weight and iron status in moderately malnourished children but did not change zinc levels.

Trust comment: Small single-blind randomized trial (n=34); LNS produced nutritional gains but no effect on zinc status was detected.

Study Details

PMID:35576279
Participants:34
Impact:no significant change
Trust score:3/5

100 mg/day elemental zinc for 3 months raised plasma zinc but did not improve nutritional status measures in CAPD patients.

Trust comment: Small double-blind RCT (n=25) with objective biochemical endpoints but limited power to detect clinical changes.

Study Details

PMID:14968473
Participants:25
Impact:+40 µg/dL (52 → 92 µg/dL)
Trust score:3/5

In this 6-week pilot RCT adding zinc (10 mg/day) to methylphenidate, plasma zinc decline was smaller with supplementation and teachers noted a non-significant improvement in ADHD scores.

Trust comment: Small, preliminary randomized double-blind trial with limited power and some non-significant clinical findings.

Study Details

PMID:22696891
Participants:40
Impact:less decline with zinc supplementation (placebo: 95.9 → 77.9 µg/dL; zinc: 90.3 → 85.0 µg/dL)
Trust score:3/5

In children 6–23 months, short-term daily zinc (5 mg) as dispersible tablet or solution similarly increased plasma zinc concentration compared with placebo.

Trust comment: Randomized, partially-masked, placebo-controlled trial with large sample and objective biomarker outcome.

Study Details

PMID:21871635
Participants:451
Impact:tablets +16.9 ±13.1 μg/dL; liquid +16.6 ±14.2 μg/dL; placebo +0.2 ±10.9 μg/dL (P<.001)
Trust score:4/5

20 mg zinc daily for 2 months had no effect on iron absorption or iron status in non‑anemic Chilean women.

Trust comment: Randomized controlled trial with isotope iron absorption measurement but modest sample size (n=44).

Study Details

PMID:18586462
Participants:44
Impact:no significant change
Trust score:4/5

Daily zinc increased plasma zinc and reduced pneumonia incidence in young children but did not change overall acute lower respiratory tract infection rates.

Trust comment: Large double-blind randomized placebo-controlled trial with active surveillance and clear endpoints.

Study Details

PMID:12052800
Participants:2482
Impact:+10.5 µmol/L (19.8 vs 9.3 µmol/L)
Trust score:5/5

Children with persistent diarrhea received zinc (20 mg) +/- other micronutrients or placebo for 2 weeks; zinc raised plasma zinc and shortened diarrheal duration in some groups.

Trust comment: Well-conducted community randomized double-blind trial with objective biochemical measures and clinical outcomes (moderate sample, subgroup effects).

Study Details

PMID:10431116
Participants:412
Impact:+38 µg/dL (Z); +14 µg/dL (Z+VM) from baseline to day 15
Trust score:4/5

Adding zinc to standard malaria treatment raised blood zinc but did not improve fever reduction, parasite clearance, or hemoglobin.

Trust comment: Large multicenter double-blind RCT with clear clinical endpoints and objective lab measures.

Study Details

PMID:12324294
Participants:1087
Impact:increased at 72 h: 10.95 ± 3.63 µmol/L (zinc) vs 10.16 ± 3.25 µmol/L (placebo), P < 0.001
Trust score:4/5

In the BLISS trial, infants following a modified baby-led weaning approach had similar zinc intakes at 7 and 12 months and similar plasma zinc at 12 months compared with spoon-fed controls.

Trust comment: Randomized controlled design with community sample and biochemical outcomes; intervention included modifications that may limit generalizability to unmodified BLW.

Study Details

PMID:29803269
Participants:206
Impact:no significant difference at 12 months
Trust score:4/5

Daily consumption of low-dose, highly bioavailable zinc-fortified filtered water increased children's blood zinc and reduced zinc deficiency but did not change diarrhea or growth.

Trust comment: Double-blind RCT with objective biochemical outcomes; modest sample size and limited power for clinical endpoints.

Study Details

PMID:26468121
Participants:277
Impact:significant increase in Zn+filter group vs Filter and Pump (time-by-treatment P = 0.026)
Trust score:4/5

Daily zinc supplementation did not reduce malaria episodes but increased plasma zinc and markedly reduced zinc deficiency.

Trust comment: Large randomized, double-blind trial with high adherence, prespecified analyses, and clinically measured endpoints.

Study Details

PMID:22131908
Participants:592
Impact:+6.4 µmol/L
Trust score:5/5

Daily fortified milk for 27 days increased dietary zinc intake and blood zinc in adolescent girls.

Trust comment: Randomized controlled trial with direct plasma zinc measurement and 108 participants; short duration limits long-term conclusions.

Study Details

PMID:23756585
Participants:108
Impact:+18.1 µg/dL (116.6 vs 98.5 µg/dL)
Trust score:4/5

Zinc (70 mg/day elemental) prevented worsening of fatigue and preserved quality of life during early chemotherapy after colorectal cancer surgery; plasma zinc rose.

Trust comment: Randomized double-blind trial with clear outcomes but very small completed sample (n=24), limiting generalizability.

Study Details

PMID:28444084
Participants:24
Impact:+~43.7 µg/dL in Zinc group (85.2→128.9 µg/dL) before fourth cycle; higher than placebo (p<0.05)
Trust score:3/5

In obese adults randomized to L-arginine vs placebo, arginine increased serum zinc and improved insulin sensitivity; changes in zinc strongly correlated with increases in insulin sensitivity.

Trust comment: Randomized double-blind trial (n=88) using gold-standard euglycemic clamp; moderate sample size and robust measures support credibility.

Study Details

PMID:23708056
Participants:88
Impact:increased in L-arginine group +1.5 μmol/L (10.7 → 12.2 μmol/L) vs ~+0.2 μmol/L in placebo
Trust score:4/5

Zinc raised plasma zinc, improved organ-failure and outcome scores, reduced inflammation, and shortened hospital stay in severe head trauma patients.

Trust comment: Double-blind RCT with clinically relevant endpoints and significant changes in several outcomes, though sample size is modest.

Study Details

PMID:28467150
Participants:100
Impact:increased (day 7 and 16; p < 0.001)
Trust score:4/5

Non-anemic infants received iron+cu with or without 10 mg zinc daily from 6–18 months; blood and urine minerals tracked at multiple timepoints.

Trust comment: Large randomized controlled trial with repeated measures and high compliance, supporting biochemical effects of daily zinc supplementation.

Study Details

PMID:24103510
Participants:251
Impact:maintained over time in zinc group vs decline in control (significant differences at 12 and 18 months)
Trust score:4/5

Double-masked, placebo-controlled 100-day trial in 100 anemic schoolchildren comparing a multi‑fortified juice (including zinc) vs non‑fortified juice; supervised administration and deworming were done.

Trust comment: Randomized, double-masked, placebo-controlled trial with supervised intake but moderate sample size (n=100); multi‑nutrient fortification complicates attributing effects solely to zinc.

Study Details

PMID:22094838
Participants:100
Impact:+20 μg/dL (83.9 → 103.9 μg/dL) in fortified group (significant); no change in control
Trust score:4/5

Study measuring plasma zinc in children with celiac disease before and after 4 weeks on a gluten-free diet (GFD); zinc‑deficient patients were randomized to GFD ± 4 weeks zinc supplementation.

Trust comment: Randomized among zinc‑deficient patients with moderate sample size; short intervention (4 weeks) limits conclusions about longer-term supplementation effects.

Study Details

PMID:20176568
Participants:134
Impact:Plasma zinc rose during 4 weeks of GFD in both groups; no additional increase with 4 weeks of zinc supplementation (GFD vs GFD+zinc similar at 4 weeks)
Trust score:3/5

Adding a 25 mg/day zinc supplement during pregnancy increased plasma zinc among women with higher total zinc intake; erythrocyte zinc tracked with habitual dietary intake.

Trust comment: Large randomized double-blind trial with biomarker outcomes, giving reliable evidence on zinc status though pregnancy physiology affects zinc levels.

Study Details

PMID:9366865
Participants:580
Impact:increased with higher total daily zinc intake (diet + supplement) at 26, 32, 38 weeks)
Trust score:4/5

Feeding preterm infants a nutrient-enriched formula normalized plasma zinc by 2 months past term without disrupting overall mineral homeostasis.

Trust comment: Prospective feeding trial in humans with clear measurement of plasma minerals but modest sample size and limited detail on long-term outcomes.

Study Details

PMID:7752008
Participants:33
Impact:normalized by ≥2 months post-term
Trust score:3/5

Daily cashew consumption for 12 weeks in adolescents with obesity reduced plasma copper and increased erythrocyte SOD activity; plasma zinc increased across both groups (likely influenced by counseling).

Trust comment: Randomized controlled trial but with substantial dropout and potential confounding from concurrent nutritional counseling; objective biochemical endpoints measured.

Study Details

PMID:39796597
Participants:81
Impact:Increased within both groups over 12 weeks (nutritional guidance effect; baseline differences present)
Trust score:4/5

Twelve weeks of zinc carnosine in older adults with low zinc increased plasma zinc modestly and reduced multiple markers of DNA damage while increasing expression of MT1A and ZIP1.

Trust comment: Placebo-controlled 12-week RCT in older adults with low zinc status reporting objective genomic and gene-expression endpoints; sample moderate.

Study Details

PMID:25755079
Participants:84
Impact:+5.69% (significant vs baseline)
Trust score:4/5

Short-term zinc supplementation (10 or 20 mg/d) raised fasting plasma zinc within 5 days; levels fell after stopping and returned to placebo within ~2 weeks.

Trust comment: Randomized, double-blind, placebo-controlled trial with frequent sampling and clear temporal effects, though limited to healthy adult men.

Study Details

PMID:20943956
Participants:58
Impact:elevated by day 5 on supplementation; returned to baseline within ~2 weeks after withdrawal
Trust score:4/5

After RYGBP surgery zinc absorption and several zinc status markers declined despite higher supplemental zinc intakes; absorption dropped sharply at 6 months.

Trust comment: Randomized supplementation groups with 18-month follow-up and objective biochemical absorption measures; moderate sample and good follow-up (56 completers).

Study Details

PMID:21865332
Participants:56
Impact:decreased after RYGBP
Trust score:4/5

17-day randomized placebo-controlled trial: 20 mg/day zinc reduced blood cell DNA strand breaks (comet assay) despite no significant change in plasma zinc.

Trust comment: Randomized placebo-controlled trial with blinded assay and clear biomarker change, though short duration and small sample.

Study Details

PMID:25491347
Participants:40
Impact:no significant change
Trust score:4/5

In a 10-week trial in Chinese schoolchildren, zinc plus other micronutrients improved neuropsychologic performance and growth more than zinc or micronutrients alone; plasma zinc rose after micronutrient treatments.

Trust comment: Large double-blind controlled trial with clear outcomes, though 10-week duration is relatively short.

Study Details

PMID:9701162
Participants:740
Impact:increased after zinc+micronutrients or micronutrients alone
Trust score:4/5

In SICU patients requiring PN, parenteral nutrition significantly increased plasma zinc levels over 7 days; glutamine-supplemented PN improved glutathione but zinc rose with PN regardless of glutamine.

Trust comment: Randomized, double-blind trial in 59 critically ill patients with clear biomarker outcomes; applicable to hospitalized PN patients though not general population.

Study Details

PMID:18065204
Participants:59
Impact:increased after 7 days of parenteral nutrition (significant in total cohort and subgroups)
Trust score:4/5

Over 2 years on a cholesterol-lowering diet, plasma zinc indicators were not adversely affected overall (no change in women; slight increase in men).

Trust comment: Large prospective 2-year cohort (n=364) with repeated biochemical measures, appropriate analyses, and clear reporting.

Study Details

PMID:12515414
Participants:364
Impact:no change (women); slight increase (men)
Trust score:4/5

In 20 treated postmenopausal women with NIDDM, 3 weeks of zinc raised plasma zinc and doubled 5'-nucleotidase activity; IGF-I rose in those with low baseline, and lipoprotein oxidation was unchanged.

Trust comment: Small, short-term controlled trial with clear biochemical endpoints but limited sample size and subgroup effects.

Study Details

PMID:9280186
Participants:40
Impact:+ increased after supplementation
Trust score:3/5

Pilot randomized trial of clioquinol (a metal-protein-attenuating compound) in Alzheimer patients: treatment was associated with reduced plasma Abeta42, raised plasma zinc, and less cognitive worsening in a more severely affected subgroup.

Trust comment: Small pilot randomized trial showing biologic effects, but limited size and exploratory endpoints reduce confidence.

Study Details

PMID:14676042
Participants:36
Impact:increased in clioquinol-treated group
Trust score:3/5

In healthy adult men, consuming zinc-biofortified wheat (+1.6 mg Zn/day) did not change plasma zinc but altered zinc-sensitive fatty-acid desaturase activities (FADS2 up, FADS1 down); antioxidant and DNA damage markers unchanged.

Trust comment: Controlled randomized feeding trial with objective biomarkers but small sample (n=36) — well-controlled but limited power for broader endpoints.

Study Details

PMID:34036355
Participants:36
Impact:No change across metabolic periods
Trust score:4/5

Pregnant women taking iron-containing prenatal supplements had much lower fractional zinc absorption and lower plasma zinc than unsupplemented controls; adding zinc to prenatal supplements reduced this adverse effect.

Trust comment: Stable-isotope measurements in a defined cohort (n=47) with clear group comparisons; sample size modest.

Study Details

PMID:10958820
Participants:47
Impact:lower in Fe group (8.2 ± 2.2 µmol/L) vs control (10.9 ± 1.8 µmol/L)
Trust score:4/5

In a 4-week randomized trial, liquid zinc supplement (15 mg ZnSO4) raised plasma zinc by ~0.72 μmol/L at day 15 and showed an overall increase across time, whereas zinc-fortified bread did not.

Trust comment: Double-blind randomized trial with adequate sample and objective biomarker outcome, though short duration.

Study Details

PMID:21562238
Participants:132
Impact:+ +0.72 μmol/L at day 15 (zinc supplement vs others); overall increased from baseline (P=0.006)
Trust score:4/5

A 14-day zinc course given during pneumonia raised plasma zinc short-term but did not reduce subsequent pneumonia or diarrhea over 6 months.

Trust comment: Large randomized, double-blind, placebo-controlled trial with high follow-up (99%) providing robust null findings for prevention.

Study Details

PMID:20631326
Participants:2599
Impact:increased immediately after 14-day supplementation but difference not detectable at 1 and 2.5 months
Trust score:5/5

In malnourished TB patients, daily zinc (15 mg) alone or with vitamin A did not speed sputum smear conversion compared with placebo; plasma zinc rose but no clinical benefit observed.

Trust comment: Randomized double-blind trial with 300 enrolled (255 completed); well-conducted but baseline imbalances and severe malnutrition limit generalizability.

Study Details

PMID:20920186
Participants:255
Impact:increased in zinc group +1.5 μmol/L (11.6 → 13.1 μmol/L at 6 months) but no superiority vs placebo
Trust score:4/5

Study in pregnant adolescents showing zinc supplementation prevented decline in plasma zinc and enhanced folic acid response when given together.

Trust comment: Moderate-sized human supplementation study but older, group allocation method unclear and outcomes biochemical rather than clinical.

Study Details

PMID:12700794
Participants:74
Impact:decline observed in groups without zinc supplementation; decline prevented in groups receiving zinc (significant)
Trust score:3/5

In pregnant women, an MMN supplement containing 15 mg zinc produced maternal plasma zinc concentrations similar to standard iron–folic acid regimens at week 30; MMN increased vitamin B12 but did not change zinc vs controls.

Trust comment: Large randomized trial with objective biomarker measurements and adherence monitoring (n=641 samples analyzed); high reliability for the reported maternal zinc results.

Study Details

PMID:27798335
Participants:641
Impact:no significant difference between MMN and standard iron–folate at week 30 (e.g., MMN ~7.77 μmol/L vs Fe60F ~7.61 μmol/L)
Trust score:5/5

Four months of 10 mg/day zinc in infants raised plasma zinc but did not change plasma copper or hematological markers of copper status.

Trust comment: Randomized controlled sub-study with direct biochemical measures showing clear increase in zinc and no change in copper or blood indices.

Study Details

PMID:15174779
Participants:115
Impact:increase (post-supplementation Z 93.0 vs C 60.6; Δ +32.4)
Trust score:4/5

Higher-iron formula showed lower plasma zinc and copper at 12 months (trend) but no cognitive benefit; zinc was measured as a secondary outcome.

Trust comment: Small randomized trial where zinc was a secondary measured outcome and iron (not zinc) was the intervention, limiting direct zinc-specific conclusions.

Study Details

PMID:11487753
Participants:58
Impact:lower at 12 months in high-iron group (70 ±14 vs 89 ±27) — suggests reduced zinc (trend)
Trust score:3/5

Fortified biscuits (including iodine) increased iodine and other micronutrient status and reduced anemia in primary schoolchildren and improved deworming effectiveness.

Trust comment: Large randomized, double-blind, placebo-controlled trial with clear biochemical outcomes and robust effect estimates.

Study Details

PMID:19321576
Participants:510
Impact:+0.61 µmol/L (95% CI: 0.26 to 0.95)
Trust score:5/5

Introducing pureed beef as first complementary food increased zinc intake and was associated with greater head growth; blood zinc did not differ between groups.

Trust comment: Randomized trial with objective biomarker measures and longitudinal follow-up, moderate sample size.

Study Details

PMID:16456417
Participants:88
Impact:no difference between groups; ~20% had <60 µg/dL
Trust score:4/5

In young Laotian children, daily preventive zinc (and some zinc regimens) increased anti-E. coli IgG levels, and preventive zinc improved antibody avidity in zinc-deficient children.

Trust comment: Randomized controlled parent trial with a well-described immunology sub-study (200 samples); subgroup effects in zinc-deficient children are plausible though based on a subset.

Study Details

PMID:36167891
Participants:200
Impact:increased with PZ and MNP (reduced prevalence of zinc deficiency)
Trust score:4/5

48 postmenopausal women with type 2 diabetes received zinc (40 mg/day) ± ALA or placebo for 12 weeks; zinc raised plasma zinc but did not change inflammatory marker concentrations.

Trust comment: Randomized double-blind placebo-controlled trial with clearly reported endpoints but modest sample size and specialized population.

Study Details

PMID:23643522
Participants:48
Impact:significant increase over time (P = .007 and P = .009)
Trust score:4/5

Daily zinc for 4 months raised plasma zinc and reduced diarrhea and pneumonia but did not change weight or length gains in young children.

Trust comment: Large, double-blind randomized placebo-controlled trial with clinical outcomes and high relevance.

Study Details

PMID:20107146
Participants:2482
Impact:+ increased (successful supplementation)
Trust score:5/5

Adolescent girls receiving zinc (tablet or zinc-rich snacks) for 10 weeks had larger increases in plasma zinc, better memory and reasoning score gains, faster reaction times, and improved salt taste sensitivity versus control.

Trust comment: Randomized school-based trial with multiple objective and functional measures and moderate sample size.

Study Details

PMID:20368377
Participants:180
Impact:J group +61.3%; D group +9.9% (J>D; p<0.1)
Trust score:4/5

One year of zinc (45 mg/day) reduced infections and some inflammatory and oxidative stress markers in older adults.

Trust comment: Randomized double-blind placebo-controlled trial with relevant biological markers and clinical outcomes, but modest sample size (n=50).

Study Details

PMID:17344507
Participants:50
Impact:increased
Trust score:4/5

combined death or ICU admission (≤30 days)

1 evidences

Randomized trial in adults with COVID-19 found oral zinc reduced the combined outcome of death or ICU admission and shortened hospital stay and symptom duration.

Trust comment: Randomized double-blind multicenter trial with meaningful clinical endpoints, though some outcomes have borderline CIs and overall sample size is moderate.

Study Details

PMID:36367144
Participants:470
Impact:reduced (OR 0.58; 95% CI 0.33–0.99)
Trust score:4/5

ICU admission

1 evidences

Randomized trial in adults with COVID-19 found oral zinc reduced the combined outcome of death or ICU admission and shortened hospital stay and symptom duration.

Trust comment: Randomized double-blind multicenter trial with meaningful clinical endpoints, though some outcomes have borderline CIs and overall sample size is moderate.

Study Details

PMID:36367144
Participants:470
Impact:5.2% (zinc) vs 11.3% (placebo); OR 0.43 (95% CI 0.21–0.87)
Trust score:4/5

mortality at 30 days

1 evidences

Randomized trial in adults with COVID-19 found oral zinc reduced the combined outcome of death or ICU admission and shortened hospital stay and symptom duration.

Trust comment: Randomized double-blind multicenter trial with meaningful clinical endpoints, though some outcomes have borderline CIs and overall sample size is moderate.

Study Details

PMID:36367144
Participants:470
Impact:6.5% (zinc) vs 9.2% (placebo); OR 0.68 (95% CI 0.34–1.35) (trend)
Trust score:4/5

length of hospital stay

2 evidences

In infants hospitalized with bronchiolitis, one week of vitamin D (plus routine care) did not produce significant improvements in respiratory outcomes or hospital stay compared with control.

Trust comment: Randomized, blinded trial with adequate reporting; moderate sample but several dropouts and short-term intervention limit ability to detect effects.

Study Details

PMID:35692038
Participants:94
Impact:no significant difference vs control
Trust score:3/5

Randomized trial in adults with COVID-19 found oral zinc reduced the combined outcome of death or ICU admission and shortened hospital stay and symptom duration.

Trust comment: Randomized double-blind multicenter trial with meaningful clinical endpoints, though some outcomes have borderline CIs and overall sample size is moderate.

Study Details

PMID:36367144
Participants:470
Impact:shorter by 3.5 days (difference 3.5 d; 95% CI 2.76–4.23) in inpatients
Trust score:4/5

symptom duration (outpatients)

1 evidences

Randomized trial in adults with COVID-19 found oral zinc reduced the combined outcome of death or ICU admission and shortened hospital stay and symptom duration.

Trust comment: Randomized double-blind multicenter trial with meaningful clinical endpoints, though some outcomes have borderline CIs and overall sample size is moderate.

Study Details

PMID:36367144
Participants:470
Impact:reduced by 1.9 days (95% CI 0.62–2.6)
Trust score:4/5

total serum bilirubin

1 evidences

Term neonates receiving oral zinc (5 mg/day) plus phototherapy had larger and faster reductions in serum bilirubin and required shorter phototherapy than placebo.

Trust comment: Double-blind RCT with clear biochemical and clinical endpoints, moderate sample size supports moderate confidence.

Study Details

PMID:37700584
Participants:106
Impact:24 h: 15.3 vs 17.1 mg/dL (MD −1.74; P<0.001); 48 h: 11.7 vs 14.62 mg/dL (MD −2.89; P<0.001); 72 h and 96 h also lower
Trust score:4/5

duration of phototherapy

1 evidences

Term neonates receiving oral zinc (5 mg/day) plus phototherapy had larger and faster reductions in serum bilirubin and required shorter phototherapy than placebo.

Trust comment: Double-blind RCT with clear biochemical and clinical endpoints, moderate sample size supports moderate confidence.

Study Details

PMID:37700584
Participants:106
Impact:mean 53.42 h (zinc) vs 71.4 h (placebo); P<0.001
Trust score:4/5

hospital stay

1 evidences

Term neonates receiving oral zinc (5 mg/day) plus phototherapy had larger and faster reductions in serum bilirubin and required shorter phototherapy than placebo.

Trust comment: Double-blind RCT with clear biochemical and clinical endpoints, moderate sample size supports moderate confidence.

Study Details

PMID:37700584
Participants:106
Impact:no significant difference (≈81.05 h vs 86.25 h; P=0.227)
Trust score:4/5

live birth

1 evidences

Large randomized trial of combined folic acid plus zinc in men undergoing infertility treatment showed no improvement in live birth or most semen parameters and an increase in sperm DNA fragmentation and GI side effects.

Trust comment: Large multicenter randomized trial with robust follow-up; however intervention combined folic acid and zinc so effects cannot be attributed to zinc alone.

Study Details

PMID:31910279
Participants:2370
Impact:no significant difference: 34% (supplement) vs 35% (placebo); risk difference −0.9% (95% CI −4.7 to 2.8)
Trust score:5/5

sperm DNA fragmentation (%)

1 evidences

Large randomized trial of combined folic acid plus zinc in men undergoing infertility treatment showed no improvement in live birth or most semen parameters and an increase in sperm DNA fragmentation and GI side effects.

Trust comment: Large multicenter randomized trial with robust follow-up; however intervention combined folic acid and zinc so effects cannot be attributed to zinc alone.

Study Details

PMID:31910279
Participants:2370
Impact:increased mean 29.7% vs 27.2%; MD +2.4% (95% CI 0.5% to 4.4%)
Trust score:5/5

Gastrointestinal adverse events

1 evidences

Large randomized trial of combined folic acid plus zinc in men undergoing infertility treatment showed no improvement in live birth or most semen parameters and an increase in sperm DNA fragmentation and GI side effects.

Trust comment: Large multicenter randomized trial with robust follow-up; however intervention combined folic acid and zinc so effects cannot be attributed to zinc alone.

Study Details

PMID:31910279
Participants:2370
Impact:higher with supplementation (e.g., nausea 4% vs 2%; vomiting 3% vs 1%)
Trust score:5/5

oral mucositis severity (OMAS)

1 evidences

Small randomized double-blind trial in head and neck cancer patients found zinc mouthwash reduced radiation-induced oral mucositis severity and pain compared with placebo.

Trust comment: Double-blind RCT but small single-center sample (n=67) and multiple intervention arms limit generalizability.

Study Details

PMID:36864527
Participants:67
Impact:week 7 mean OMAS 2.71 (zinc) vs 6.86 (placebo); significant reduction weeks 2–7
Trust score:3/5

pain severity (VAS)

1 evidences

Small randomized double-blind trial in head and neck cancer patients found zinc mouthwash reduced radiation-induced oral mucositis severity and pain compared with placebo.

Trust comment: Double-blind RCT but small single-center sample (n=67) and multiple intervention arms limit generalizability.

Study Details

PMID:36864527
Participants:67
Impact:week 7 mean VAS 3.58 (zinc) vs 7.60 (placebo); significant reduction weeks 2–7
Trust score:3/5

alertness and attention

1 evidences

Open-label RCT in preterm neonates found zinc supplementation until 3 months corrected age improved alertness/attention and reduced signs of hyper-excitability and abnormal reflexes.

Trust comment: Randomized trial provides direct human data but open-label design and modest sample size (n=100) increase risk of bias.

Study Details

PMID:26615342
Participants:100
Impact:greater proportion normal at 40 weeks post-conceptional age (P=0.02)
Trust score:3/5

hyper-excitability signs

1 evidences

Open-label RCT in preterm neonates found zinc supplementation until 3 months corrected age improved alertness/attention and reduced signs of hyper-excitability and abnormal reflexes.

Trust comment: Randomized trial provides direct human data but open-label design and modest sample size (n=100) increase risk of bias.

Study Details

PMID:26615342
Participants:100
Impact:fewer in zinc group at 40 weeks (P=0.001) and at 3 months corrected age (P=0.003)
Trust score:3/5

serum alkaline phosphatase

1 evidences

Open-label RCT in preterm neonates found zinc supplementation until 3 months corrected age improved alertness/attention and reduced signs of hyper-excitability and abnormal reflexes.

Trust comment: Randomized trial provides direct human data but open-label design and modest sample size (n=100) increase risk of bias.

Study Details

PMID:26615342
Participants:100
Impact:higher mean level at 3 months in zinc group (statistically significant)
Trust score:3/5

genital wart count

1 evidences

50 patients with genital warts received cryotherapy plus oral zinc or placebo for 2 months; zinc provided no added benefit but caused more stomach side effects.

Trust comment: Randomized double-blind split-side RCT with clear endpoints but small sample (n=50).

Study Details

PMID:36987822
Participants:50
Impact:no significant difference vs placebo
Trust score:4/5

gastrointestinal adverse effects

2 evidences

Randomized study in healthy adults showing that several oral zinc regimens halved hepatic copper uptake by PET/CT; adverse GI effects were common and varied by zinc salt and dosing.

Trust comment: Randomized human intervention with objective PET/CT primary outcome and clear per-protocol analyses, but modest sample size and non-blinded design.

Study Details

PMID:36038585
Participants:37
Impact:21/37 participants had ≥1 common side effect (nausea, gastric discomfort, headache); more frequent with zinc acetate (P=0.001)
Trust score:4/5

50 patients with genital warts received cryotherapy plus oral zinc or placebo for 2 months; zinc provided no added benefit but caused more stomach side effects.

Trust comment: Randomized double-blind split-side RCT with clear endpoints but small sample (n=50).

Study Details

PMID:36987822
Participants:50
Impact:increased (significant) in zinc group
Trust score:4/5

HDL cholesterol

3 evidences

In type 2 diabetic patients, combined mineral (Mg+Zn) plus vitamins C+E increased HDL cholesterol and apolipoprotein A1 over 3 months; Mg+Zn alone showed no significant changes.

Trust comment: Randomized double-blind trial but effects reported for combined micronutrient group (Mg+Zn+vitamins), limiting attribution to zinc alone.

Study Details

PMID:15163474
Participants:69
Impact:increase by 24% in minerals+vitamins (MV) group (50.4 ± 19.3 vs 40.6 ± 10.8 mg/dl), p < 0.01
Trust score:3/5

Children with NASH took zinc for 16 weeks and had lower liver enzyme and inflammation and higher HDL, but no change in liver fat on ultrasound.

Trust comment: Randomized, placebo-controlled trial in children with registration and clear endpoints but modest sample size.

Study Details

PMID:37989929
Participants:60
Impact:increased (significant)
Trust score:4/5

Three months of combined myo-inositol and zinc (with GOS) did not improve HOMA-IR overall but modestly improved HDL and showed reduced fasting insulin and HOMA-IR in a severe-obesity subgroup.

Trust comment: Randomized double-blind trial but small sample, short duration, and zinc was combined with myo-inositol (attribution to zinc alone unclear).

Study Details

PMID:39781581
Participants:50
Impact:increase vs placebo (p=0.05)
Trust score:3/5

severe or invasive infection incidence

1 evidences

250 Ugandan children <5 years with sickle cell anemia received daily 10 mg zinc or placebo for 12 months; zinc raised serum zinc but did not reduce severe/invasive infections, with a preliminary signal of fewer strokes or deaths.

Trust comment: Large, well-conducted randomized double-blind placebo-controlled trial with intention-to-treat analysis and predefined infection endpoints.

Study Details

PMID:36735400
Participants:250
Impact:no reduction (aIRR 1.04, 95% CI 0.81–1.32; p=0.78)
Trust score:5/5

serum zinc level / zinc deficiency prevalence

1 evidences

250 Ugandan children <5 years with sickle cell anemia received daily 10 mg zinc or placebo for 12 months; zinc raised serum zinc but did not reduce severe/invasive infections, with a preliminary signal of fewer strokes or deaths.

Trust comment: Large, well-conducted randomized double-blind placebo-controlled trial with intention-to-treat analysis and predefined infection endpoints.

Study Details

PMID:36735400
Participants:250
Impact:serum zinc increased +10.8 μg/dL (61.4→72.2); zinc deficiency fell 64.5%→41.3% (p=0.001)
Trust score:5/5

composite stroke or death

1 evidences

250 Ugandan children <5 years with sickle cell anemia received daily 10 mg zinc or placebo for 12 months; zinc raised serum zinc but did not reduce severe/invasive infections, with a preliminary signal of fewer strokes or deaths.

Trust comment: Large, well-conducted randomized double-blind placebo-controlled trial with intention-to-treat analysis and predefined infection endpoints.

Study Details

PMID:36735400
Participants:250
Impact:fewer events in zinc arm (2 vs 9; aHR 0.22, 95% CI 0.05–1.00; p=0.05) — preliminary
Trust score:5/5

duration of diarrhea

5 evidences

In malnourished young children with acute diarrhea, zinc supplementation tended to reduce stool output and duration and increased serum zinc and weight gain.

Trust comment: Randomized double-blind trial with moderate sample size; some primary outcomes were borderline significant but biochemical and weight changes were significant.

Study Details

PMID:9370894
Participants:111
Impact:-14% (overall; p = 0.06; subgroup reductions significant)
Trust score:4/5

In children with rotavirus diarrhea, zinc alone or zinc plus Saccharomyces boulardii shortened diarrhea and hospital stay compared to rehydration alone.

Trust comment: Large randomized treatment-group study in children with clear clinical outcomes, though exact effect sizes not reported in text excerpt.

Study Details

PMID:21261786
Participants:480
Impact:decreased (statistically significant vs control in zinc and zinc+S. boulardii groups)
Trust score:4/5

808 children (6–59 months) hospitalized for acute diarrhea were randomized to placebo, zinc, or zinc+cupric syrup for 14 days; supplementation did not shorten diarrhea duration or reduce stool output versus placebo.

Trust comment: Large, double-blind randomized controlled trial with robust methods and high follow-up, showing no therapeutic benefit on primary outcomes.

Study Details

PMID:19416499
Participants:808
Impact:no significant difference vs placebo
Trust score:5/5

An infant formula containing probiotics, prebiotics, fiber and increased zinc+iron shortened duration of acute diarrhea versus control formula.

Trust comment: Randomized trial but multifactorial formula (zinc included among other active ingredients) so individual zinc contribution is unclear.

Study Details

PMID:17704024
Participants:58
Impact:−0.82 days (1.63 vs 2.45 days; ~−33%)
Trust score:3/5

A zinc-containing gel ORS increased fluid intake and reduced diarrhea duration and persistence at 72 h in young children with acute gastroenteritis.

Trust comment: Randomized controlled trial with clear endpoints but modest sample size.

Study Details

PMID:25822861
Participants:83
Impact:shorter mean duration (p=0.001)
Trust score:4/5

stool weight / stool output

1 evidences

808 children (6–59 months) hospitalized for acute diarrhea were randomized to placebo, zinc, or zinc+cupric syrup for 14 days; supplementation did not shorten diarrhea duration or reduce stool output versus placebo.

Trust comment: Large, double-blind randomized controlled trial with robust methods and high follow-up, showing no therapeutic benefit on primary outcomes.

Study Details

PMID:19416499
Participants:808
Impact:no significant difference vs placebo
Trust score:5/5

Serum zinc

45 evidences

Malnourished children had lower blood zinc and copper; zinc levels correlated with linear growth.

Trust comment: Clinical observational measurements in 58 children with clear correlations reported but cross-sectional design and small sample limit causal inference.

Study Details

PMID:10829989
Participants:58
Impact:significantly decreased in children with severe PEM
Trust score:3/5

In hemodialysis patients zinc increased serum zinc and some B-cell marker levels, but did not produce a clear between-group improvement in vaccine antibody response.

Trust comment: Small randomized sample with objective labs but limited power and mixed within/between-group results.

Study Details

PMID:9684909
Participants:37
Impact:increased in supplemented hemodialysis patients (p<0.01)
Trust score:3/5

808 children (6–59 months) hospitalized for acute diarrhea were randomized to placebo, zinc, or zinc+cupric syrup for 14 days; supplementation did not shorten diarrhea duration or reduce stool output versus placebo.

Trust comment: Large, double-blind randomized controlled trial with robust methods and high follow-up, showing no therapeutic benefit on primary outcomes.

Study Details

PMID:19416499
Participants:808
Impact:increased from baseline in zinc-supplemented groups (group-level changes reported)
Trust score:5/5

Antihypertensive monotherapy was associated with decreased serum zinc and increased urinary zinc; an optimal-mineral diet restored serum zinc.

Trust comment: Controlled clinical monitoring in a small sample shows plausible drug–mineral interactions but is limited by sample size and short follow-up.

Study Details

PMID:24452943
Participants:45
Impact:significant decrease after antihypertensive treatment
Trust score:3/5

Placebo-controlled trial in patients with treatment-resistant viral warts: oral zinc sulphate produced high rates of complete wart clearance in completers.

Trust comment: Randomized placebo-controlled trial showing large effect in completers, but notable dropout and small completer numbers moderate confidence.

Study Details

PMID:11952542
Participants:43
Impact:Low at baseline; treatment response correlated with serum zinc increase
Trust score:4/5

Six weeks of zinc raised serum zinc but did not change IGF-1 or bone turnover markers in peripubertal girls.

Trust comment: Small randomized trial with short duration and limited outcome changes; increases confidence in zinc absorption but limited clinical effect data.

Study Details

PMID:10465179
Participants:47
Impact:increased with supplementation
Trust score:3/5

A 3-year homestead food production programme did not change haemoglobin, iron, vitamin A, or zinc biomarker status in women or children at endline.

Trust comment: Large, well-designed cluster-randomized trial with biomarker measurements and appropriate adjustments; null effects for zinc outcomes.

Study Details

PMID:40387380
Participants:3413
Impact:No intervention effect on serum zinc (nonpregnant women adjusted β ≈ −14.8 µg/L, p=0.21; children adjusted β ≈ −13.1 µg/L, p=0.23) and no reduction in zinc deficiency prevalence.
Trust score:5/5

In Indonesian infants, zinc supplements raised serum zinc, but combined iron+zinc was less effective at improving iron status than iron alone.

Trust comment: Large community-based randomized trial with substantial completed-sample biochemical data (n=549) and clear interaction findings.

Study Details

PMID:12663287
Participants:549
Impact:+~28% (11.58 vs 9.06 μmol/L in zinc vs placebo)
Trust score:5/5

Zinc combined with iron (with or without vitamin A) improved growth and micronutrient status in stunted infants, whereas zinc alone worsened iron/hemoglobin markers and growth trajectory.

Trust comment: Large double-blind community RCT with clear subgroup effects (stunted, low hemoglobin), supporting internal validity.

Study Details

PMID:17468087
Participants:800
Impact:improved with Zn+Fe and Zn+Fe+vitA
Trust score:4/5

In a 3-month randomized double-blind trial, daily 30 mg iron plus 30 mg zinc improved hemoglobin, total body iron and serum zinc versus placebo in women of childbearing age.

Trust comment: Randomized double-blind trial with moderate sample size and clinically relevant biochemical outcomes.

Study Details

PMID:25582309
Participants:81
Impact:significant increase vs placebo and vs iron alone
Trust score:4/5

Weekly simultaneous iron + zinc supplementation reduced severe diarrhea and, in undernourished infants, reduced severe ALRI compared with control.

Trust comment: Double-blind, randomized community trial with biological measures and morbidity outcomes; subgroup effects in undernourished children should be interpreted cautiously.

Study Details

PMID:14652364
Participants:799
Impact:increased in zinc and iron+zinc groups at 12 months
Trust score:4/5

In 40 men with type 2 diabetes and normal zinc status, high-dose zinc raised serum zinc but did not change oxidative damage markers or vascular function over 3 months.

Trust comment: Randomized placebo-controlled study with objective biomarkers; limited by small sample and single population (men with normal zinc).

Study Details

PMID:21840002
Participants:40
Impact:significant increase in treatment group
Trust score:4/5

56 overweight/obese NAFLD patients received calorie restriction plus either 30 mg/day zinc or placebo for 12 weeks; zinc raised serum zinc and improved some liver enzymes and waist circumference but did not change steatosis.

Trust comment: Randomized double-blind RCT with clear biochemical endpoints but small sample and short duration limit generalizability.

Study Details

PMID:32020523
Participants:56
Impact:increased (significant, p<0.001)
Trust score:4/5

A multivitamin-mineral supplement containing zinc increased serum and cellular zinc and showed signals of improved mitochondrial function and antioxidant enzyme activity in healthy volunteers.

Trust comment: Randomized placebo-controlled design but intervention was a multinutrient formula so effects cannot be attributed to zinc alone.

Study Details

PMID:28171220
Participants:150
Impact:increased at 3 and 6 months (p<0.001)
Trust score:3/5

Daily iron supplementation in pregnant women reduced serum copper and zinc concentrations in the second and third trimesters.

Trust comment: Randomized double-blind placebo-controlled trial (n=66) showing consistent biochemical changes but modest sample size.

Study Details

PMID:17963760
Participants:66
Impact:↓ significant decrease in supplemented group (P < 0.001)
Trust score:4/5

6 months of 15–30 mg/day zinc raised serum and urinary zinc with no major overall adverse effects on iron, copper status or lipids, though 30 mg/day showed some age/sex‑dependent changes.

Trust comment: Large randomized double‑blind study (n=387) with dose arms and 6‑month follow‑up; well conducted though subgroup signals noted.

Study Details

PMID:17313720
Participants:387
Impact:significant increase with supplementation
Trust score:4/5

Double-blind randomized trial in hemodialysis patients showed that 60 days of zinc (100 mg/day elemental) raised serum zinc and lowered serum leptin in women.

Trust comment: Randomized double-blind placebo-controlled trial (n=60) with clear biochemical endpoints; moderate size and limited duration (60 days).

Study Details

PMID:24188897
Participants:60
Impact:significant increase in the zinc-supplemented group
Trust score:4/5

In malnourished young children with acute diarrhea, zinc supplementation tended to reduce stool output and duration and increased serum zinc and weight gain.

Trust comment: Randomized double-blind trial with moderate sample size; some primary outcomes were borderline significant but biochemical and weight changes were significant.

Study Details

PMID:9370894
Participants:111
Impact:+2.4 μmol/L (increase vs -0.3 μmol/L in control; p < 0.001)
Trust score:4/5

Overweight/obese adults given 30 mg zinc daily for 12 weeks had higher blood zinc and BDNF and felt less depressed than those on placebo.

Trust comment: Randomized double-blind placebo-controlled trial with modest sample (46 completers); clear biochemical and clinical signal but relatively small N.

Study Details

PMID:24621065
Participants:46
Impact:increased
Trust score:4/5

In hemodialysis patients with zinc deficiency, one year of zinc supplementation was associated with increases in body fat weight; serum zinc correlated positively with fat mass.

Trust comment: Open-label RCT in a specific patient group with small sample size; plausible finding but limited generalizability.

Study Details

PMID:39400501
Participants:48
Impact:positively correlated with body fat weight (p < 0.01)
Trust score:3/5

A 6-month multi-micronutrient beverage increased serum vitamin A and zinc in Nigerian schoolchildren.

Trust comment: Large double-blind, placebo-controlled school-based RCT with biochemical endpoints and high completion.

Study Details

PMID:21677073
Participants:534
Impact:+1.0 ± 0.2 μmol/L (micronutrient) vs +0.6 ± 0.2 μmol/L (control); p = 0.031
Trust score:4/5

In women with gestational diabetes, 6 weeks of zinc (30 mg/day) increased serum zinc and antioxidant capacity and lowered hs-CRP, without changing pregnancy outcomes.

Trust comment: Randomized, double-blind, placebo-controlled trial but small sample (n=50) limits precision.

Study Details

PMID:26465829
Participants:50
Impact:mean change +8.5 mg/dL vs −3.6 mg/dL in placebo (P=0.006)
Trust score:4/5

Daily ABB C1® (contains 15 mg zinc/day) for 30–35 days increased serum zinc and selenium and tended to enhance vaccine-associated immune markers versus placebo in vaccinated volunteers.

Trust comment: Randomised double-blind trial but small and heterogeneous sample with mixed vaccine cohorts; zinc levels increased though clinical immune-endpoint differences were not consistently significant.

Study Details

PMID:34959898
Participants:64
Impact:increase (statistically significant in cohort comparisons; p<0.001 reported for influenza subgroup)
Trust score:3/5

Three months of curcumin increased serum zinc and the zinc/copper ratio and lowered serum copper in adults with β-thalassemia intermedia.

Trust comment: Small (n=30) randomized double-blind trial measuring mineral biomarkers; limited sample size reduces generalizability.

Study Details

PMID:33432439
Participants:30
Impact:increase (significant after 3 months)
Trust score:3/5

Infants randomized to 10 mg zinc as a dispersible tablet, zinc in MNP, or placebo for 24 weeks; exchangeable zinc pool (EZP) and serum zinc measured before and after.

Trust comment: Large, randomized, partially blinded RCT sub-study with robust isotope methodology and high retention.

Study Details

PMID:35276840
Participants:156
Impact:positive correlation with EZP (R2=0.08, p=0.0001); pattern mirrored EZP changes
Trust score:5/5

In Thai infants, zinc supplements raised blood zinc but did not improve growth; combined iron+zinc altered iron markers versus single supplements.

Trust comment: Large randomized placebo-controlled factorial trial (n=609) with measured biochemical endpoints supports high trustworthiness.

Study Details

PMID:16920862
Participants:609
Impact:+~70% (16.7 vs 9.8 μmol/L in zinc vs placebo)
Trust score:5/5

Randomized double-blind trial of daily multivitamin and trace element supplement (including zinc 20 mg) vs placebo in adults measuring serum nutrient levels and antioxidant markers over 6 months.

Trust comment: Large randomized trial showing expected rises in nutrient biomarkers for a multinutrient supplement that included zinc; effects are biomarker-level and part of combined treatment.

Study Details

PMID:9627910
Participants:401
Impact:significant increase in serum zinc after 3 months of supplementation (vs placebo)
Trust score:4/5

Triple-fortified rice raised serum zinc more than control rice in schoolchildren.

Trust comment: Randomized school-feeding intervention with biochemical outcome (serum zinc) and adequate sample size.

Study Details

PMID:23303870
Participants:203
Impact:increased in both groups but greater rise in fortified group (11.3 vs 10.6 μmol/L; P < 0.05)
Trust score:4/5

Randomized trial in children with coeliac disease: adding four weeks of zinc to a gluten-free diet increased serum zinc and iron more than diet alone; copper change was not significantly different.

Trust comment: Randomized controlled trial in 71 children; direct human evidence but moderate sample size and short supplement duration.

Study Details

PMID:29141505
Participants:71
Impact:greater increase with GFD + zinc (significant)
Trust score:4/5

Zinc (100 mg/day) for 2 months increased blood zinc and antioxidant markers and reduced lipid peroxidation in hemodialysis patients.

Trust comment: Double-blind randomized crossover RCT in 65 HD patients with clear biochemical endpoints and significant p-values.

Study Details

PMID:23140661
Participants:65
Impact:↑ significant increase (P < .001)
Trust score:4/5

Young women given multivitamin plus 7 mg zinc daily for 10 weeks showed reduced anger and depression scores and higher serum zinc versus multivitamin alone.

Trust comment: Small randomized double-blind pilot (n=30) with positive mood and serum zinc changes but limited sample size for broad generalization.

Study Details

PMID:20087376
Participants:30
Impact:increased
Trust score:3/5

In zinc-deficient hemodialysis patients, three months of zinc supplementation increased serum zinc, improved red blood cell osmotic fragility and reduced lipid peroxidation (MDA), but some side effects occurred with zinc.

Trust comment: Randomized study in a specific clinical population (n=34) showing biochemical and functional RBC improvements, but small size and noted side effects reduce generalizability.

Study Details

PMID:11979503
Participants:34
Impact:significant increase after 3 months of zinc supplementation
Trust score:3/5

In 79 primary-school children given iron, zinc, or both for 4 months, serum zinc increased with zinc supplementation; effects on ferritin differed by regimen and plasma retinol decreased across supplemented groups.

Trust comment: Randomized double-blind trial with moderate sample size; results internally consistent though some biomarker changes are complex.

Study Details

PMID:19070056
Participants:79
Impact:significantly increased in all supplemented groups (zinc and iron+zinc)
Trust score:4/5

In 40 obese young women randomized to 30 mg/day zinc or placebo for 8 weeks, zinc raised serum and urinary zinc and reduced some inflammatory markers (hs-CRP, IL-6) but did not change leptin or adiponectin.

Trust comment: Controlled intervention with small groups and short duration; results plausible but sample size limits precision.

Study Details

PMID:24402636
Participants:40
Impact:increased by ~15% with supplementation (p<0.05)
Trust score:3/5

In zinc-deficient people with HIV on ART, 24 weeks of daily zinc raised zinc levels and reduced a monocyte activation marker (sCD14) but did not change most inflammation or cardiovascular markers.

Trust comment: Randomized, double-blind, placebo-controlled trial with objective biomarker outcomes but modest sample size and 24-week duration.

Study Details

PMID:40431411
Participants:95
Impact:+33.50 μg/dL (+53.17%) vs +8.60 μg/dL in placebo (p<0.0001)
Trust score:4/5

Randomized study in healthy adults showing that several oral zinc regimens halved hepatic copper uptake by PET/CT; adverse GI effects were common and varied by zinc salt and dosing.

Trust comment: Randomized human intervention with objective PET/CT primary outcome and clear per-protocol analyses, but modest sample size and non-blinded design.

Study Details

PMID:36038585
Participants:37
Impact:Higher after zinc acetate than zinc gluconate (post-treatment group means e.g., acetate up to 25.2 µmol/L vs gluconate groups ~17–19 µmol/L; P≈0.02–0.03)
Trust score:4/5

Double-blind RCT: oral zinc raised serum zinc but did not improve rosacea severity vs placebo over 90 days.

Trust comment: Randomized double-blind trial with objective scoring but modest sample size (n=44) limiting power to detect small effects.

Study Details

PMID:22435439
Participants:44
Impact:increased in zinc group (P<0.001)
Trust score:4/5

Daily oral polaprezinc (34 mg Zn/day) in zinc-deficient hemodialysis patients increased serum zinc, lowered serum copper and ferritin, and reduced the erythropoietin responsiveness index (ERI), allowing lower ESA requirements.

Trust comment: Randomized multicenter trial in zinc-deficient HD patients with objective biochemical and clinical endpoints; open-label and modest size are limitations.

Study Details

PMID:25988769
Participants:66
Impact:Increased from 53±6 to 80±18 µg/dL at 12 months in polaprezinc group (control ~56 µg/dL)
Trust score:4/5

Infants counseled to eat red meat more frequently from 6–12 months had higher meat intake and improved haemoglobin/hematocrit but no change in zinc status or linear growth at 12 months.

Trust comment: Randomized trial with biochemical measures but small sample (76 completers) and short follow-up limit generalizability.

Study Details

PMID:23945724
Participants:76
Impact:no significant change
Trust score:3/5

A 4-month randomized trial in women with low iron stores tested dietary advice, iron supplement, or placebo and measured zinc status; iron supplements with meals appeared to lower zinc status.

Trust comment: Randomized, partially blinded placebo-controlled human trial with measured biomarkers; moderate risk from subgroup sizes but overall reliable.

Study Details

PMID:20416130
Participants:78
Impact:increased in diet and placebo groups (adjusted P ≤ 0.002); no rise in iron supplement group (iron with meals lowered zinc; between-group P = 0.02)
Trust score:4/5

Fortified porridge improved anemia, iron and selenium status in Zambian infants but did not significantly raise overall serum zinc.

Trust comment: Large double-blind randomized trial (n=743) with objective biochemical endpoints; limited efficacy on overall zinc status.

Study Details

PMID:21411608
Participants:743
Impact:no overall change (ratio 1.09; 95% CI 0.66–1.80); improved in subgroup with low baseline Hb (P=0.024)
Trust score:4/5

In 60 patients with traumatic fractures, 50 mg elemental zinc daily for 60 days raised serum zinc and alkaline phosphatase and improved radiographic callus formation versus placebo.

Trust comment: Randomized double-blind placebo-controlled clinical trial in humans with clear outcomes, but moderate sample size.

Study Details

PMID:18813411
Participants:60
Impact:significant increase (zinc group vs placebo)
Trust score:4/5

Randomized workplace nutrition intervention providing oral nutrition supplements (multi‑vitamin/mineral formula including minerals) plus education vs education alone in female workers; intervention improved biochemical micronutrient markers including serum zinc, iron, and total serum calcium and reduced micronutrient deficiency prevalence.

Trust comment: Large randomized trial with objective biochemical outcomes, but use of a multinutrient ONS means effects cannot be attributed to zinc alone.

Study Details

PMID:38684383
Participants:500
Impact:+4.6 μg/dL (from 49.0 to 53.6 μg/dL)
Trust score:4/5

In 60 women with gestational diabetes, 6 weeks of magnesium-zinc-calcium-vitamin D reduced inflammation and oxidative stress markers and modestly lowered fasting glucose.

Trust comment: Double-blind, placebo-controlled randomized trial with clear biomarker outcomes though multi-nutrient co-supplementation limits attribution to zinc alone.

Study Details

PMID:30922259
Participants:60
Impact:+4.1 ± 1.8 mg/dL vs +0.4 ± 2.6 in placebo (P < 0.001)
Trust score:4/5

Twelve weeks of 30 mg/day zinc reduced TLR-2 expression and improved a nonocular Behçet's disease activity score versus placebo.

Trust comment: Double-blind randomized placebo-controlled design with clear biomarker and clinical outcome changes supports moderate-high confidence.

Study Details

PMID:35413570
Participants:50
Impact:increase in zinc group (reported significance ≤0.05)
Trust score:4/5

immunological failure (CD4 <200 cells/mm3 events)

1 evidences

231 HIV-infected adults with low plasma zinc were randomized to zinc (12–15 mg/day) or placebo for 18 months; zinc reduced immunological failure and diarrheal episodes but did not change viral load or mortality.

Trust comment: Randomized controlled trial with longitudinal follow-up and biological monitoring; solid effect on CD4 outcomes though generalizability may be limited to zinc-deficient HIV cohorts.

Study Details

PMID:20455705
Participants:231
Impact:reduced ~4-fold (relative rate 0.24; 95% CI 0.10–0.56; p<0.002)
Trust score:4/5

diarrhea rate

1 evidences

231 HIV-infected adults with low plasma zinc were randomized to zinc (12–15 mg/day) or placebo for 18 months; zinc reduced immunological failure and diarrheal episodes but did not change viral load or mortality.

Trust comment: Randomized controlled trial with longitudinal follow-up and biological monitoring; solid effect on CD4 outcomes though generalizability may be limited to zinc-deficient HIV cohorts.

Study Details

PMID:20455705
Participants:231
Impact:reduced (OR 0.4; 95% CI 0.183–0.981; p=0.019)
Trust score:4/5

HIV viral load

1 evidences

231 HIV-infected adults with low plasma zinc were randomized to zinc (12–15 mg/day) or placebo for 18 months; zinc reduced immunological failure and diarrheal episodes but did not change viral load or mortality.

Trust comment: Randomized controlled trial with longitudinal follow-up and biological monitoring; solid effect on CD4 outcomes though generalizability may be limited to zinc-deficient HIV cohorts.

Study Details

PMID:20455705
Participants:231
Impact:no effect
Trust score:4/5

blood zinc level

1 evidences

Personalized supplementation raised vitamin D blood levels but did not reduce how often or how severe upper respiratory infections occurred in these healthy adults.

Trust comment: Randomized double-blind study but small sample, low event count (few URIs) and individualized allocation complicate interpretation.

Study Details

PMID:38794638
Participants:59
Impact:increased in supplemented subgroup but between-group end values not significantly different
Trust score:3/5

URI frequency and severity

1 evidences

Personalized supplementation raised vitamin D blood levels but did not reduce how often or how severe upper respiratory infections occurred in these healthy adults.

Trust comment: Randomized double-blind study but small sample, low event count (few URIs) and individualized allocation complicate interpretation.

Study Details

PMID:38794638
Participants:59
Impact:no reduction in occurrence or severity
Trust score:3/5

neuropsychometric performance (PHES subtests)

1 evidences

69 cirrhotic patients with minimal hepatic encephalopathy received zinc (45 mg/day elemental) or placebo for 12 weeks; zinc improved several psychomotor test scores and quality-of-life measures and increased serum zinc.

Trust comment: Randomized controlled trial with objective psychometric endpoints and biochemical confirmation, but modest sample size.

Study Details

PMID:34582657
Participants:69
Impact:improved (significant improvements in NCT-A, NCT-B, SDT, DST vs placebo)
Trust score:4/5

serum zinc level

6 evidences

69 cirrhotic patients with minimal hepatic encephalopathy received zinc (45 mg/day elemental) or placebo for 12 weeks; zinc improved several psychomotor test scores and quality-of-life measures and increased serum zinc.

Trust comment: Randomized controlled trial with objective psychometric endpoints and biochemical confirmation, but modest sample size.

Study Details

PMID:34582657
Participants:69
Impact:increased (68.47→91.21 mcg/dL; p<0.001)
Trust score:4/5

In this phase 1 trial of VLBW preterm infants, serum zinc levels fell over 21 days in both groups, and human milk additives tested did not maintain serum zinc levels.

Trust comment: Phase 1 randomized, double-blind trial in humans but small sample (n=40) limits generalizability.

Study Details

PMID:39374901
Participants:40
Impact:decrease from day 1 to day 21 (statistically significant within groups, p < 0.01)
Trust score:3/5

Zinc acetate hydrate (50 mg/day) increased serum zinc more than polaprezinc (34 mg/day) in maintenance hemodialysis patients and led to a decline in serum copper.

Trust comment: Prospective randomized trial with moderate sample size; open-label and single-center may limit generalizability.

Study Details

PMID:31794152
Participants:91
Impact:greater increase with zinc acetate hydrate vs polaprezinc at 3 months (significant)
Trust score:4/5

Zinc supplementation in zinc‑deficient ESRD patients increased serum zinc and substantially reduced plasma homocysteine vs placebo over ~6 weeks.

Trust comment: Double‑blind RCT in a defined zinc‑deficient ESRD population with clear biochemical endpoints; short duration but robust internal validity.

Study Details

PMID:23475369
Participants:100
Impact:Increased significantly with supplementation (p<0.05)
Trust score:4/5

Pregnant women given 20 mg elemental zinc daily had higher blood zinc at delivery compared with placebo.

Trust comment: Double-blind randomized controlled trial with adequate sample and clear biochemical outcome, but modest sample for some paired analyses.

Study Details

PMID:19810298
Participants:242
Impact:+14.7 microg/dL (mean increase; 95% CI 5–23; P=0.002)
Trust score:4/5

In HCV patients, supplementation with BCAAs plus zinc (10 mg/day) for 60 days increased BCAA:tyrosine ratio and serum zinc; in those with elevated baseline AFP, supplementation reduced AFP.

Trust comment: Randomized multicenter trial with objective biochemical endpoints, but small sample and combined BCAA+zinc intervention limit zinc‑only attribution.

Study Details

PMID:25394681
Participants:53
Impact:increased vs placebo (76 ±11 vs 68 ±11 µg/dl; P=0.0497)
Trust score:3/5

health-related quality of life (SF-36)

1 evidences

69 cirrhotic patients with minimal hepatic encephalopathy received zinc (45 mg/day elemental) or placebo for 12 weeks; zinc improved several psychomotor test scores and quality-of-life measures and increased serum zinc.

Trust comment: Randomized controlled trial with objective psychometric endpoints and biochemical confirmation, but modest sample size.

Study Details

PMID:34582657
Participants:69
Impact:improved across multiple domains vs placebo
Trust score:4/5

sCD14 (monocyte activation)

1 evidences

In zinc-deficient people with HIV on ART, 24 weeks of daily zinc raised zinc levels and reduced a monocyte activation marker (sCD14) but did not change most inflammation or cardiovascular markers.

Trust comment: Randomized, double-blind, placebo-controlled trial with objective biomarker outcomes but modest sample size and 24-week duration.

Study Details

PMID:40431411
Participants:95
Impact:−56.31 ng/mL in treatment vs +101.71 ng/mL in placebo (significant difference; p=0.02)
Trust score:4/5

CD4 count / virologic suppression

1 evidences

In zinc-deficient people with HIV on ART, 24 weeks of daily zinc raised zinc levels and reduced a monocyte activation marker (sCD14) but did not change most inflammation or cardiovascular markers.

Trust comment: Randomized, double-blind, placebo-controlled trial with objective biomarker outcomes but modest sample size and 24-week duration.

Study Details

PMID:40431411
Participants:95
Impact:no significant change; all remained virologically suppressed
Trust score:4/5

incidence of acute lower respiratory infection (ALRI)

1 evidences

Two weeks of prophylactic oral zinc in infants (6–11 months) did not change overall ARI incidence but reduced duration measures and substantially lowered acute lower respiratory infection incidence over follow-up.

Trust comment: Randomized, double-blind community RCT with clear clinical endpoints and good follow-up in a target population.

Study Details

PMID:25362008
Participants:272
Impact:−62% (reported reduction; effect persisted for 5 months)
Trust score:4/5

duration of ARI episodes

1 evidences

Two weeks of prophylactic oral zinc in infants (6–11 months) did not change overall ARI incidence but reduced duration measures and substantially lowered acute lower respiratory infection incidence over follow-up.

Trust comment: Randomized, double-blind community RCT with clear clinical endpoints and good follow-up in a target population.

Study Details

PMID:25362008
Participants:272
Impact:−12% (reported) and days of illness −15% (reported)
Trust score:4/5

incidence of overall ARI

1 evidences

Two weeks of prophylactic oral zinc in infants (6–11 months) did not change overall ARI incidence but reduced duration measures and substantially lowered acute lower respiratory infection incidence over follow-up.

Trust comment: Randomized, double-blind community RCT with clear clinical endpoints and good follow-up in a target population.

Study Details

PMID:25362008
Participants:272
Impact:no significant effect
Trust score:4/5

Plasma zinc

17 evidences

Perioperative zinc plus vitamin E supplementation increased plasma zinc, reduced inflammatory markers, and shortened hospital length of stay after CABG surgery.

Trust comment: Randomized double-blind trial with clear clinical and biomarker outcomes, but supplementation combined zinc with vitamin E.

Study Details

PMID:37891226
Participants:78
Impact:increased (p<0.0001)
Trust score:4/5

In a small pilot study of HIV patients with poor CD4 recovery, zinc supplementation raised plasma zinc and was associated with CD4 increases in those initially zinc-deficient.

Trust comment: Small pilot randomized component with very limited sample size (total n=31) and subgroup randomization; findings are preliminary.

Study Details

PMID:24270132
Participants:31
Impact:median change +29 μg/dL with supplementation vs +4.5 μg/dL with placebo (in low-zinc subgroup)
Trust score:3/5

14 days of zinc supplementation raised plasma zinc but did not improve weight gain or speed recovery from diarrhea in hospitalized malnourished children.

Trust comment: Double-blind randomized placebo-controlled inpatient trial (n=87) with clear clinical and biochemical endpoints; biochemical but not clinical benefit observed.

Study Details

PMID:10103334
Participants:87
Impact:significant increase by day 14 (magnitude not specified)
Trust score:4/5

Measured plasma and erythrocyte minerals in hospitalized patients on antipsychotics; erythrocyte magnesium decreased whereas plasma magnesium was unchanged; no clear plasma zinc change reported.

Trust comment: Clinical observational measurement in a modest sample; informative but limited by size and clinical heterogeneity.

Study Details

PMID:15466963
Participants:56
Impact:no clear change reported
Trust score:3/5

In a double-blind RCT, oral zinc (2 mg/kg/day) did not raise plasma zinc significantly but was associated with improved weight gain and fewer infection episodes during 60 days.

Trust comment: Randomized double-blind placebo-controlled design supports internal validity though sample size is small.

Study Details

PMID:23963274
Participants:38
Impact:no significant increase with supplementation
Trust score:4/5

In elderly subjects, oral zinc (or zinc+arginine) restored plasma zinc levels but did not enhance influenza antibody responses or lymphocyte counts.

Trust comment: Large randomized controlled design in elderly participants with biologic and immunologic endpoints; clear negative clinical immunogenicity result.

Study Details

PMID:10408666
Participants:384
Impact:increased/restored to levels found in younger people (no numeric values provided)
Trust score:4/5

Ten-week zinc- and micronutrient-rich food or ayurvedic zinc supplements increased plasma zinc and reduced zinc deficiency prevalence in adolescent girls.

Trust comment: Randomized 10-week intervention in 180 girls with biochemical outcome measures and reported percentage changes.

Study Details

PMID:22129855
Participants:180
Impact:↑ 9.9% (food supplement) and ↑ 61.3% (ayurvedic zinc)
Trust score:4/5

Crossover feeding study in women showed lower zinc absorption and a small drop in plasma zinc on a lactoovovegetarian diet compared with an omnivorous diet.

Trust comment: Controlled crossover feeding study with direct isotopic absorption measures in 21 women; small sample but strong design for absorption outcomes.

Study Details

PMID:9497185
Participants:21
Impact:5% reduction (within normal range)
Trust score:4/5

In non-anemic young women, 12 weeks of low-dose iron supplementation improved iron stores but caused a significant drop in plasma zinc.

Trust comment: Randomised supplementation trial but small sample (n=40); outcome measures credible though magnitude of zinc change not provided in the summary.

Study Details

PMID:23602244
Participants:40
Impact:decrease (statistically significant, p=0.004)
Trust score:3/5

Randomized double-blind placebo-controlled trial giving 45 mg zinc/day for 6 months to healthy elderly adults and measuring plasma zinc and inflammatory/oxidative markers.

Trust comment: Randomized double-blind trial with clear biomarker outcomes though small sample size limits precision and generalizability.

Study Details

PMID:20427734
Participants:40
Impact:plasma zinc increased after supplementation vs placebo
Trust score:4/5

In young patients with thalassemia and low bone mass, zinc supplementation increased whole-body bone mass and areal bone density over 18 months.

Trust comment: Randomized placebo-controlled trial with objective DXA outcomes but small completed sample limits precision.

Study Details

PMID:23945720
Participants:32
Impact:significant increase vs placebo (P = 0.014)
Trust score:4/5

Randomized double-blind trial in obese hypertensive adults: 3 months of Spirulina (2 g/day) decreased serum iron but did not markedly change serum calcium or magnesium.

Trust comment: Randomized controlled design but small sample and spirulina is a multi-component supplement; zinc concentration change was not significant.

Study Details

PMID:26779620
Participants:50
Impact:no significant change: spirulina 10.03 → 9.78 µmol/L, placebo 10.71 → 10.92 µmol/L (ANOVA treatment P=0.517)
Trust score:3/5

Two-week zinc supplementation raised plasma zinc by day 14 but did not significantly shorten diarrhoea duration or reduce severity or incidence versus control.

Trust comment: Randomized clinical trial with adequate sample but open-label and non-placebo-controlled, limiting clinical inference despite biomarker change.

Study Details

PMID:16354711
Participants:280
Impact:significant increase in supplemented group by day 14
Trust score:3/5

In a large randomized trial of young children, preventive zinc (daily) and a zinc-containing micronutrient powder increased plasma zinc but did not improve linear growth or weight; the micronutrient powder improved iron status and modestly reduced anemia among initially anemic children.

Trust comment: Large, registered, double-blind randomized trial with high adherence and objective biomarker and anthropometric measures.

Study Details

PMID:30580974
Participants:2943
Impact:preventive zinc 66.4 µg/dL vs control 56.0 µg/dL at endline (+10.4 µg/dL; p<0.001)
Trust score:5/5

A 22-week school-based multiple micronutrient supplement (including zinc 10 mg/day) increased plasma zinc and reduced zinc deficiency prevalence in 6–9-year-old children.

Trust comment: Large, well-conducted cluster-randomised, double-blind trial with high retention and appropriate biochemical corrections; findings for zinc are direct and significant.

Study Details

PMID:33580103
Participants:347
Impact:+0.9 µmol/L (95% CI 0.4, 1.4)
Trust score:5/5

Randomized trial in young children comparing 10 mg/day zinc alone, zinc+multivitamins/minerals, or placebo for ~6 months; morbidity, growth, and plasma micronutrients measured.

Trust comment: Well-conducted randomized controlled trial with adequate sample and objective biomarker and morbidity outcomes; direct zinc supplementation arm provides high internal validity.

Study Details

PMID:14985222
Participants:246
Impact:change from baseline to 6 mo: placebo +6.1 µg/dL; Zn alone +27.3 µg/dL; Zn+VM +16.2 µg/dL (P<0.0001)
Trust score:5/5

Giving one egg daily for six months did not improve plasma zinc, selenium, copper or magnesium; plasma iron decreased in the egg group.

Trust comment: Large randomized controlled trial with blinded outcome assessment and measured biomarkers; secondary analysis with some sample loss but appropriate adjustments.

Study Details

PMID:37095119
Participants:387
Impact:Mean difference −0.6 µg/dL (95% CI −13.57 to 14.78); no significant change
Trust score:4/5

linear growth (LAZ)

1 evidences

In a large randomized trial of young children, preventive zinc (daily) and a zinc-containing micronutrient powder increased plasma zinc but did not improve linear growth or weight; the micronutrient powder improved iron status and modestly reduced anemia among initially anemic children.

Trust comment: Large, registered, double-blind randomized trial with high adherence and objective biomarker and anthropometric measures.

Study Details

PMID:30580974
Participants:2943
Impact:no significant effect (no difference between groups)
Trust score:5/5

anemia / ferritin (micronutrient powder arm)

1 evidences

In a large randomized trial of young children, preventive zinc (daily) and a zinc-containing micronutrient powder increased plasma zinc but did not improve linear growth or weight; the micronutrient powder improved iron status and modestly reduced anemia among initially anemic children.

Trust comment: Large, registered, double-blind randomized trial with high adherence and objective biomarker and anthropometric measures.

Study Details

PMID:30580974
Participants:2943
Impact:micronutrient powder increased ferritin and modestly reduced anemia in children who were anemic at baseline (significant vs some other groups)
Trust score:5/5

quality of life (physical domain)

1 evidences

Twelve weeks of 30 mg/day zinc in young women with PMS improved the physical domain of quality of life; overall quality-of-life improvement was seen within the zinc group but not significantly different vs placebo, and sleep quality showed a marginal improvement.

Trust comment: Small randomized double-blind trial with subjective outcomes; some domain-specific effects but limited sample size.

Study Details

PMID:32514756
Participants:60
Impact:+5.55 ± 3.71 points in zinc vs +0.13 ± 2.87 in placebo (p<0.001)
Trust score:3/5

overall quality of life (total score)

1 evidences

Twelve weeks of 30 mg/day zinc in young women with PMS improved the physical domain of quality of life; overall quality-of-life improvement was seen within the zinc group but not significantly different vs placebo, and sleep quality showed a marginal improvement.

Trust comment: Small randomized double-blind trial with subjective outcomes; some domain-specific effects but limited sample size.

Study Details

PMID:32514756
Participants:60
Impact:+9.185 ± 7.29 within zinc group (not significant vs placebo)
Trust score:3/5

sleep quality (Pittsburgh score)

1 evidences

Twelve weeks of 30 mg/day zinc in young women with PMS improved the physical domain of quality of life; overall quality-of-life improvement was seen within the zinc group but not significantly different vs placebo, and sleep quality showed a marginal improvement.

Trust comment: Small randomized double-blind trial with subjective outcomes; some domain-specific effects but limited sample size.

Study Details

PMID:32514756
Participants:60
Impact:trend to improvement in zinc group (−1.48 ± 4.12, p=0.07)
Trust score:3/5

PMS physical symptoms

1 evidences

Twelve weeks of 30 mg/day zinc in women with PMS reduced physical and psychological PMS symptoms and increased total antioxidant capacity and BDNF, with no change in hs-CRP.

Trust comment: Randomized, double-blind trial with biochemical and clinical endpoints but small sample size limits generalizability.

Study Details

PMID:31154571
Participants:60
Impact:significant decrease vs placebo (p=0.03)
Trust score:4/5

PMS psychological symptoms

1 evidences

Twelve weeks of 30 mg/day zinc in women with PMS reduced physical and psychological PMS symptoms and increased total antioxidant capacity and BDNF, with no change in hs-CRP.

Trust comment: Randomized, double-blind trial with biochemical and clinical endpoints but small sample size limits generalizability.

Study Details

PMID:31154571
Participants:60
Impact:significant decrease vs placebo (p=0.006)
Trust score:4/5

BDNF and total antioxidant capacity

1 evidences

Twelve weeks of 30 mg/day zinc in women with PMS reduced physical and psychological PMS symptoms and increased total antioxidant capacity and BDNF, with no change in hs-CRP.

Trust comment: Randomized, double-blind trial with biochemical and clinical endpoints but small sample size limits generalizability.

Study Details

PMID:31154571
Participants:60
Impact:BDNF increased (p=0.01); total antioxidant capacity increased (p<0.001); hs-CRP unchanged
Trust score:4/5

lymphocyte concentration

1 evidences

Nine months of daily preventive zinc (7 mg/day) in young Laotian children did not change cytokine or T-cell concentrations but was associated with lower lymphocyte counts overall and lower eosinophil counts in the subgroup with lower baseline zinc.

Trust comment: Well-powered randomized trial with objective hematologic and immunologic measures and appropriate adjustments.

Study Details

PMID:32119742
Participants:512
Impact:endline mean 5,018 ± 158 cells/µL in preventive zinc vs 5,640 ± 160 in control (difference ≈ −622 cells/µL; p=0.032)
Trust score:5/5

eosinophil concentration (baseline low zinc subgroup)

1 evidences

Nine months of daily preventive zinc (7 mg/day) in young Laotian children did not change cytokine or T-cell concentrations but was associated with lower lymphocyte counts overall and lower eosinophil counts in the subgroup with lower baseline zinc.

Trust comment: Well-powered randomized trial with objective hematologic and immunologic measures and appropriate adjustments.

Study Details

PMID:32119742
Participants:512
Impact:524 ± 44 vs 600 ± 41 cells/µL in control (difference ≈ −76 cells/µL; p=0.012)
Trust score:5/5

T-cell cytokines / T-cell counts

1 evidences

Nine months of daily preventive zinc (7 mg/day) in young Laotian children did not change cytokine or T-cell concentrations but was associated with lower lymphocyte counts overall and lower eosinophil counts in the subgroup with lower baseline zinc.

Trust comment: Well-powered randomized trial with objective hematologic and immunologic measures and appropriate adjustments.

Study Details

PMID:32119742
Participants:512
Impact:no significant change
Trust score:5/5

sleep onset latency

1 evidences

Eating zinc-rich foods (and zinc-enriched yeast with astaxanthin) for 12 weeks improved objective actigraphy measures of sleep onset latency and sleep efficiency in healthy adults.

Trust comment: Randomized, double-blind trial with objective actigraphy outcomes in a moderate-size healthy cohort.

Study Details

PMID:28019085
Participants:120
Impact:decreased (improved) in zinc-rich and zinc+astaxanthin groups versus placebo (actigraphy)
Trust score:4/5

sleep efficiency

1 evidences

Eating zinc-rich foods (and zinc-enriched yeast with astaxanthin) for 12 weeks improved objective actigraphy measures of sleep onset latency and sleep efficiency in healthy adults.

Trust comment: Randomized, double-blind trial with objective actigraphy outcomes in a moderate-size healthy cohort.

Study Details

PMID:28019085
Participants:120
Impact:improved in zinc-rich food group versus placebo (actigraphy)
Trust score:4/5

time to fall asleep

1 evidences

Eating zinc-rich foods (and zinc-enriched yeast with astaxanthin) for 12 weeks improved objective actigraphy measures of sleep onset latency and sleep efficiency in healthy adults.

Trust comment: Randomized, double-blind trial with objective actigraphy outcomes in a moderate-size healthy cohort.

Study Details

PMID:28019085
Participants:120
Impact:decreased in zinc-rich food group (significant vs placebo)
Trust score:4/5

Weight-for-age Z-score

4 evidences

Daily low-dose MNP containing bioavailable iron and 2.5 mg zinc reduced iron and zinc deficiencies and modestly improved weight-for-age over 23 weeks.

Trust comment: Double-blind randomized controlled trial with clear biochemical endpoints, though zinc dose was low and some outcomes lack reported effect sizes.

Study Details

PMID:21178093
Participants:200
Impact:increased (P<0.05; exact numeric change not reported)
Trust score:4/5

A 6-month lipid-based nutrient supplement (providing zinc among other nutrients) modestly increased length- and weight-for-age in young children, with effects persisting 6 months later.

Trust comment: Large randomized controlled trial with clear growth outcomes, but supplement contained multiple nutrients so zinc-specific effects cannot be isolated.

Study Details

PMID:24225356
Participants:589
Impact:+0.12 ± 0.02 (significant vs control)
Trust score:4/5

In 6–12 month Indonesian infants, single zinc improved some growth measures while iron improved growth and psychomotor development; combined iron+zinc showed no benefit at the tested ratio.

Trust comment: Large randomized community RCT (n=680) with clear outcomes; robust but interaction effects limit simple interpretation.

Study Details

PMID:15321815
Participants:680
Impact:increased (Zn vs placebo; significant at 12 mo)
Trust score:4/5

Infants born small for gestational age who received daily zinc showed greater weight and length gains over the first 6 months versus placebo.

Trust comment: Small double-blind randomized trial with clear anthropometric outcomes and significant effects on growth in this specific population.

Study Details

PMID:7636643
Participants:68
Impact:improved in zinc group (6-month z score change -1.28 to -0.66 vs -1.43 to -1.47 in placebo; p < 0.001)
Trust score:4/5

knee-heel length

1 evidences

In 6–12 month Indonesian infants, single zinc improved some growth measures while iron improved growth and psychomotor development; combined iron+zinc showed no benefit at the tested ratio.

Trust comment: Large randomized community RCT (n=680) with clear outcomes; robust but interaction effects limit simple interpretation.

Study Details

PMID:15321815
Participants:680
Impact:increased (Zn and Fe vs placebo; significant at 12 mo)
Trust score:4/5

psychomotor development (BSID PDI)

1 evidences

In 6–12 month Indonesian infants, single zinc improved some growth measures while iron improved growth and psychomotor development; combined iron+zinc showed no benefit at the tested ratio.

Trust comment: Large randomized community RCT (n=680) with clear outcomes; robust but interaction effects limit simple interpretation.

Study Details

PMID:15321815
Participants:680
Impact:increased (Fe vs placebo; significant at 12 mo)
Trust score:4/5

prevalence of persistent diarrhoea

1 evidences

In Bangladeshi toddlers, zinc and vitamin A together reduced persistent diarrhoea and dysentery, but zinc alone was associated with increased acute lower respiratory infection (ALRI); vitamin A reduced that adverse effect when given together.

Trust comment: Large double-blind RCT (n=800) with reported rate ratios and CIs; high methodological quality.

Study Details

PMID:11498488
Participants:800
Impact:decreased ~21% (rate ratio 0.79; 95% CI 0.66–0.94)
Trust score:5/5

prevalence of dysentery

1 evidences

In Bangladeshi toddlers, zinc and vitamin A together reduced persistent diarrhoea and dysentery, but zinc alone was associated with increased acute lower respiratory infection (ALRI); vitamin A reduced that adverse effect when given together.

Trust comment: Large double-blind RCT (n=800) with reported rate ratios and CIs; high methodological quality.

Study Details

PMID:11498488
Participants:800
Impact:decreased ~20% (rate ratio 0.80; 95% CI 0.67–0.95)
Trust score:5/5

acute lower respiratory infection (incidence and prevalence)

1 evidences

In Bangladeshi toddlers, zinc and vitamin A together reduced persistent diarrhoea and dysentery, but zinc alone was associated with increased acute lower respiratory infection (ALRI); vitamin A reduced that adverse effect when given together.

Trust comment: Large double-blind RCT (n=800) with reported rate ratios and CIs; high methodological quality.

Study Details

PMID:11498488
Participants:800
Impact:incidence increased +62% (RR 1.62; 1.16–2.25); prevalence increased +107% (RR 2.07; 1.76–2.44) with zinc alone; interaction with vitamin A reduced this adverse effect
Trust score:5/5

Plaque index (PI)

2 evidences

In a 21-day crossover experimental gingivitis model, the dentifrice containing triclosan + pvm/ma + Zn + PPi reduced plaque, gingivitis, and bleeding indices versus control.

Trust comment: Double-blind crossover design but small sample and zinc was combined with multiple active ingredients (not isolated zinc effect).

Study Details

PMID:10914890
Participants:25
Impact:-28.8% vs control
Trust score:3/5

In young adults with plaque-induced gingivitis, adjunctive zinc-containing intraoral stents reduced gingival inflammation (GI) more than control over 8 weeks.

Trust comment: Randomized double-blind placebo-controlled trial with objective clinical indices but small sample (41 completers) and short follow-up (8 weeks).

Study Details

PMID:41001958
Participants:41
Impact:no significant intergroup difference
Trust score:4/5

blood lead concentration (PbB)

1 evidences

Among lead-exposed schoolchildren, zinc (and iron) supplementation for 6 months did not reduce blood lead concentrations compared with placebo; iron improved iron status but did not lower lead.

Trust comment: Large double-blind field RCT with high completion (517) and relevant biochemical measures; results are clear for PbB outcome.

Study Details

PMID:16920858
Participants:517
Impact:decreased in all groups over time but no additional reduction from zinc or iron vs placebo (no treatment effect after adjustment)
Trust score:4/5

iron status

2 evidences

Among lead-exposed schoolchildren, zinc (and iron) supplementation for 6 months did not reduce blood lead concentrations compared with placebo; iron improved iron status but did not lower lead.

Trust comment: Large double-blind field RCT with high completion (517) and relevant biochemical measures; results are clear for PbB outcome.

Study Details

PMID:16920858
Participants:517
Impact:improved with iron supplementation (significant improvement in iron markers)
Trust score:4/5

Probiotic-supplemented milk modestly improved growth (weight/height velocity) but had no effect on iron or zinc status in Indonesian children.

Trust comment: Large randomized trial with clear endpoints; intervention was probiotics in milk (indirectly measured zinc status).

Study Details

PMID:23700339
Participants:494
Impact:0% (no significant change)
Trust score:4/5

absorbed zinc (mg/day)

2 evidences

In young Indian children, iron- and zinc-biofortified pearl millet increased absorption of both minerals versus control millet; absorbed iron and zinc exceeded physiological requirements.

Trust comment: Randomized, isotope-based absorption study with careful dietary control but small sample (n≈40); methods are strong for absorption endpoints.

Study Details

PMID:23843474
Participants:40
Impact:biofortified 1.0 ± 0.5 vs control 0.7 ± 0.2; increase ≈ +0.3 mg/d (P=0.03)
Trust score:4/5

Fortifying wheat with higher zinc increased total absorbed zinc while fractional absorption fell with higher fortification; values remained stable over ~7 weeks.

Trust comment: Controlled feeding and repeated measures with moderate sample size provide reliable absorption data.

Study Details

PMID:15755834
Participants:41
Impact:increased with higher fortification (0.71 → 1.11 → 1.34 mg/d) and remained stable over ~7 weeks
Trust score:4/5

absorbed iron (mg/day)

1 evidences

In young Indian children, iron- and zinc-biofortified pearl millet increased absorption of both minerals versus control millet; absorbed iron and zinc exceeded physiological requirements.

Trust comment: Randomized, isotope-based absorption study with careful dietary control but small sample (n≈40); methods are strong for absorption endpoints.

Study Details

PMID:23843474
Participants:40
Impact:biofortified 0.7 ± 0.5 vs control 0.2 ± 0.2; increase ≈ +0.5 mg/d (P<0.0001)
Trust score:4/5

dietary zinc intake (mg/day)

1 evidences

In young Indian children, iron- and zinc-biofortified pearl millet increased absorption of both minerals versus control millet; absorbed iron and zinc exceeded physiological requirements.

Trust comment: Randomized, isotope-based absorption study with careful dietary control but small sample (n≈40); methods are strong for absorption endpoints.

Study Details

PMID:23843474
Participants:40
Impact:biofortified 5.8 ± 2.1 vs control 3.3 ± 1.1 (P<0.0001)
Trust score:4/5

zinc fractional absorption

1 evidences

Crossover study in formula-fed infants comparing higher vs lower dietary fiber in weaning cereals; measured stool characteristics and mineral (including zinc) absorption using stable isotopes.

Trust comment: Human crossover study with isotope measurements of zinc absorption in infants; subgroup sample for isotope measures limited but methods are direct and appropriate.

Study Details

PMID:8642490
Participants:57
Impact:45.3% (8.0% DF) vs 41.2% (1.8% DF)
Trust score:4/5

total zinc absorption

2 evidences

Reducing dietary phytate (corn-soy diet) increased zinc absorption in children recovering from tuberculosis but had no effect in well children.

Trust comment: Human stable-isotope study with objective absorption measures but very small short-term sample (n=23), limiting external validity.

Study Details

PMID:11110854
Participants:23
Impact:In TB-recovery children increased from 100 to 169 µg/(kg·d) (+69 µg/(kg·d), P<0.05)
Trust score:3/5

In 60 children, NaFeEDTA- or FeSO4-fortified soy sauce did not change fractional zinc absorption or total zinc absorption compared with non-fortified soy sauce.

Trust comment: Randomized human study with modest sample (n=60) and direct measurement of zinc absorption; limited by small size.

Study Details

PMID:25582850
Participants:60
Impact:no significant difference among groups (P=0.5940)
Trust score:3/5

exchangeable zinc pool (EZP)

4 evidences

Infants randomized to 10 mg zinc as a dispersible tablet, zinc in MNP, or placebo for 24 weeks; exchangeable zinc pool (EZP) and serum zinc measured before and after.

Trust comment: Large, randomized, partially blinded RCT sub-study with robust isotope methodology and high retention.

Study Details

PMID:35276840
Participants:156
Impact:significant increase in dispersible tablet group vs placebo (tablet > MNP; MNP increase not significant)
Trust score:5/5

Adding 10 mg zinc to a micronutrient powder markedly increased absorbed zinc and improved the exchangeable zinc pool in infants.

Trust comment: Nested randomized study using stable isotope methodology (≈38 infants); high-quality biochemical measures though sample size was small.

Study Details

PMID:24225451
Participants:38
Impact:+0.8 mg/kg at follow-up (3.7 vs 4.5 mg/kg)
Trust score:4/5

In 9-month-old breastfed infants, meat or zinc-fortified cereal provided more absorbed zinc than iron-only fortified cereal; human-milk zinc contributed <25% of needs.

Trust comment: Randomized feeding trial with direct isotope-based zinc absorption measures but small sample size limits generalizability.

Study Details

PMID:22648720
Participants:45
Impact:EZP correlated with zinc intake (r = 0.43, P < 0.01) and TAZ (r = 0.54, P < 0.001)
Trust score:4/5

In Kenyan infants (~9 months), iron in MNP did not affect zinc absorption, but overall zinc absorption from maize-based diets was low and often below physiologic requirement.

Trust comment: Randomized, double-blind isotope study with rigorous methods but limited completed sample size and high inflammatory burden.

Study Details

PMID:25493942
Participants:27
Impact:no difference between MNP+Fe and MNP−Fe; EZP lower than expected compared with infants in hygienic settings
Trust score:4/5

inflammation effect on EZP

1 evidences

Infants randomized to 10 mg zinc as a dispersible tablet, zinc in MNP, or placebo for 24 weeks; exchangeable zinc pool (EZP) and serum zinc measured before and after.

Trust comment: Large, randomized, partially blinded RCT sub-study with robust isotope methodology and high retention.

Study Details

PMID:35276840
Participants:156
Impact:no association between elevated CRP/AGP and EZP
Trust score:5/5

serum ferritin

5 evidences

A 22-week school-based multiple micronutrient supplement (including zinc 10 mg/day) increased plasma zinc and reduced zinc deficiency prevalence in 6–9-year-old children.

Trust comment: Large, well-conducted cluster-randomised, double-blind trial with high retention and appropriate biochemical corrections; findings for zinc are direct and significant.

Study Details

PMID:33580103
Participants:347
Impact:+9.1 µg/L (95% CI 2.3, 15.9)
Trust score:5/5

Adding 15 mg zinc to prenatal iron+folate did not alter hemoglobin or ferritin changes during pregnancy.

Trust comment: Large randomized double-masked trial with measured hematologic outcomes supports reliable null finding for added zinc.

Study Details

PMID:10731503
Participants:645
Impact:no significant difference by supplement type
Trust score:4/5

1125 adolescent girls received a fortified beverage for up to 12 months; fortification (including zinc) improved hemoglobin, ferritin, retinol, and short-term growth measures.

Trust comment: Large randomized double-blind placebo-controlled trial with objective biochemical and anthropometric outcomes, but multinutrient product means effects cannot be attributed solely to zinc.

Study Details

PMID:17709456
Participants:1125
Impact:increased (significant at 6 and continued increase at 12 months)
Trust score:4/5

Children/adolescents in a randomized methylphenidate discontinuation trial had ferritin and zinc measured to see biochemical changes and whether baseline levels moderated symptom/working memory changes after withdrawal.

Trust comment: Randomized discontinuation design but small sample and preliminary analyses; results reported as exploratory/moderating findings.

Study Details

PMID:35714551
Participants:63
Impact:decreased after methylphenidate withdrawal
Trust score:3/5

Daily feeding with iron- and zinc-biofortified pearl millet did not change iron or zinc status or growth overall but raised hemoglobin in some subgroups (males and iron‑deficient children).

Trust comment: Large randomized controlled feeding trial with negative overall findings but plausible subgroup effects; well conducted.

Study Details

PMID:35299084
Participants:223
Impact:no significant change overall
Trust score:4/5

baseline ferritin (moderator)

1 evidences

Children/adolescents in a randomized methylphenidate discontinuation trial had ferritin and zinc measured to see biochemical changes and whether baseline levels moderated symptom/working memory changes after withdrawal.

Trust comment: Randomized discontinuation design but small sample and preliminary analyses; results reported as exploratory/moderating findings.

Study Details

PMID:35714551
Participants:63
Impact:higher baseline ferritin associated with larger worsening of teacher-rated hyperactivity-impulsivity and ODD after withdrawal
Trust score:3/5

baseline serum zinc (moderator)

1 evidences

Children/adolescents in a randomized methylphenidate discontinuation trial had ferritin and zinc measured to see biochemical changes and whether baseline levels moderated symptom/working memory changes after withdrawal.

Trust comment: Randomized discontinuation design but small sample and preliminary analyses; results reported as exploratory/moderating findings.

Study Details

PMID:35714551
Participants:63
Impact:higher baseline zinc associated with larger increase in working memory errors after withdrawal
Trust score:3/5

serum zinc concentration

55 evidences

23 weeks of daily whole or fortified milk increased serum vitamin A, zinc and iron in schoolchildren, with larger gains in those initially deficient but no difference between milk types.

Trust comment: Large randomized double-blind controlled study with objective micronutrient measurements, though both arms improved limiting attribution to added fortification.

Study Details

PMID:29565149
Participants:328
Impact:↑ significantly within both groups; greater increases in initially deficient children; no between-group difference after supplementation
Trust score:4/5

12-week double-blind RCT in Cambodian women: MMN (including 15 mg zinc) raised serum zinc; adding 60 mg iron blunted that increase.

Trust comment: Large, double-blind randomized trial with complete follow-up (760 completers) and objective biochemical outcomes, high trust.

Study Details

PMID:31174215
Participants:760
Impact:MMN group 12.3 μmol/L vs placebo 11.2 μmol/L at 12 wk (+1.1 μmol/L); Fe+MMN 11.6 μmol/L (≈−0.7 μmol/L vs MMN)
Trust score:5/5

Children aged 1–5 years received 10 mg/day zinc for 4 months; zinc normalized serum zinc and improved hemoglobin but did not change growth measures.

Trust comment: Blinded randomized clinical trial with small sample (n=58); biochemical improvements clear but anthropometric responses absent.

Study Details

PMID:16738738
Participants:58
Impact:Significant increase/normalization of serum zinc in supplementation group (P=0.023)
Trust score:3/5

Preterm infants given zinc plus multivitamin grew more and had higher zinc levels and fewer illnesses over 6 weeks compared to multivitamin alone.

Trust comment: Randomized controlled trial with 100 preterm infants and objective biochemical and clinical outcomes; short follow-up and some endpoints not fully quantified in the excerpt.

Study Details

PMID:20308765
Participants:100
Impact:Post-supplement Group I 105 ±16.5 µg/dL vs Group II 82.2 ±17.4 µg/dL (P < 0.05)
Trust score:4/5

Compared girls with sickle cell disease to matched controls; lower zinc was linked to later puberty and later first menstruation.

Trust comment: Cross-sectional case-control study with clear associations but cannot prove causation and potential confounding.

Study Details

PMID:29870301
Participants:162
Impact:Subjects 58.01 ±10.58 µg/dL vs controls 68.37 ±8.67 µg/dL; P=0.001 (lower in SCA)
Trust score:3/5

Pregnant women with gestational diabetes took zinc or placebo for 6 weeks; zinc improved blood sugar control and some lipids.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear biochemical outcomes but modest sample size (n=58).

Study Details

PMID:26233572
Participants:58
Impact:+6.9 ±13.2 mg/dL (zinc) vs -1.5 ±16.5 mg/dL (placebo); P=0.03
Trust score:4/5

In migraine patients, 8 weeks of zinc (50 mg elemental) reduced monthly attack frequency; other migraine measures changed less consistently.

Trust comment: Randomized double-blind trial with complete follow-up (n=80) and adjusted analyses, but modest sample size and some outcomes lost significance after adjustment.

Study Details

PMID:32928216
Participants:80
Impact:+3.58 μg/dL (adjusted change vs placebo)
Trust score:4/5

Children with low serum zinc ate zinc-fortified bread for 90 days and showed increases in zinc status, some growth markers, and immune responses.

Trust comment: Small controlled feeding study with clear biochemical and clinical signals but limited sample size (n=24) reduces generalizability.

Study Details

PMID:9481631
Participants:24
Impact:Increased (p<0.01)
Trust score:3/5

Daily 10 mg zinc for 3 months raised serum zinc and reduced serum iron (AUC) in healthy 8–9-year-old children without causing anemia.

Trust comment: Randomized, triple-blind trial with full follow-up (n=30); well-controlled biochemical measures though sample size is small.

Study Details

PMID:25192026
Participants:30
Impact:increase (basal serum zinc increased more in zinc-supplemented group)
Trust score:4/5

In 100 adolescent girls, higher serum zinc was associated with slightly lower depression and anxiety scores.

Trust comment: Cross-sectional study of 100 students showing correlations (cannot infer causality).

Study Details

PMID:28064416
Participants:100
Impact:lower dietary zinc intake in zinc-deficient subjects (p=0.001); serum zinc inversely correlated with mood scores
Trust score:3/5

Zinc treatment/supplementation in children with ETEC diarrhea increased serum zinc and some innate immune markers (complement C3, phagocytosis) but reduced oxidative burst capacity.

Trust comment: Well-sized clinical follow-up with immunologic measures and clear statistical differences, though some immune changes are complex to interpret.

Study Details

PMID:20237063
Participants:248
Impact:higher in zinc-treated and zinc-treated+supplemented groups vs untreated (P < 0.001)
Trust score:4/5

In a trial of iron supplementation in anaemic lactating women, serum zinc decreased in supplemented groups (measured in a 53-person subset), with larger declines after daily vs weekly iron.

Trust comment: Randomized intervention but serum zinc assessed in a limited subset (n=53), undermining precision and generalizability.

Study Details

PMID:16167707
Participants:53
Impact:decreased after iron supplementation; greater reduction with daily vs weekly dosing (zinc deficiency detected in supplemented groups but not control)
Trust score:3/5

Zinc supplementation corrected low serum zinc levels but did not improve clinical outcomes such as illness scores, hospital stay, or ventilation duration in infants with severe pneumonia.

Trust comment: Prospective randomized trial but non-blinded with a small sample and no clinical benefit observed.

Study Details

PMID:26684319
Participants:96
Impact:normalized by day ~12 in treatment group
Trust score:3/5

Double-blind randomized trial in 106 alcohol-dependent inpatients comparing 21 days of micronutrient supplementation (including zinc 20 mg) versus placebo and measuring serum vitamin and trace element levels.

Trust comment: Randomized double-blind trial with adequate sample size and clear biomarker outcomes; changes are biochemical, short-term.

Study Details

PMID:12897045
Participants:106
Impact:significantly increased in supplement group vs placebo after 21 days
Trust score:4/5

Elderly people given a liquid multi-nutrient supplement maintained BMI and had improved intake of several nutrients and some measures of well-being; serum zinc did not change.

Trust comment: Randomized 16-week intervention in older adults with measured biomarkers, but multi-nutrient supplement and lack of zinc-specific effects limit zinc attribution.

Study Details

PMID:10608948
Participants:71
Impact:no change (within normal range)
Trust score:3/5

In hospitalized COVID-19 patients with low baseline zinc, high-dose IV zinc safely increased serum zinc above the deficiency cutoff by Day 6 with minimal local infusion irritation.

Trust comment: Randomized double-blind pilot with small sample and incomplete recruitment; shows biological correction of deficiency but underpowered for clinical outcomes.

Study Details

PMID:33629384
Participants:33
Impact:HDIVZn increased serum zinc above deficiency cutoff (10.7 μmol/L) by Day 6; P<0.001
Trust score:3/5

Cluster RCT sub-study in infants aged 6–12 months: 4 months of daily supplementation (MNP, syrup, or fortified food) increased serum zinc in all groups, with syrup showing the largest increase; MNP reduced anemia prevalence.

Trust comment: Large cluster-randomized trial with biochemical endpoints and high compliance in subgroups, providing strong evidence for zinc status improvement.

Study Details

PMID:35684031
Participants:283
Impact:Significant increase in all groups; largest increase in syrup group (mean changes all pairwise significant)
Trust score:5/5

Randomized open-label trial of polaprezinc (zinc compound) after AMI showed increased serum zinc, lower IL-6/max CPK index and improved left ventricular ejection fraction at 9 months versus control.

Trust comment: Randomized but open-label and small (n=50) with baseline imbalances; results suggest benefit but warrant larger trials.

Study Details

PMID:30855449
Participants:50
Impact:significantly increased with polaprezinc
Trust score:3/5

Daily prenatal multiple micronutrients did not improve maternal serum zinc or retinol compared with iron-only supplementation; possible small improvement in folate postpartum.

Trust comment: Randomized prenatal supplementation with supervised dosing and biochemical outcomes, though biochemical sub-sampling and generally adequate baseline status limit detectable effects.

Study Details

PMID:19668928
Participants:507
Impact:no difference between MM and Fe groups
Trust score:4/5

Among 3–4-year-old children, counseling to reduce saturated fat did not change zinc intake or serum zinc concentrations compared with controls.

Trust comment: Randomized prospective study subset with measured dietary intake and laboratory zinc indicators; moderate sample size and direct zinc measurements.

Study Details

PMID:9280175
Participants:79
Impact:no significant difference (intervention 11.2±1.9 vs control 10.5±1.6 µmol/L; NS)
Trust score:4/5

In asthmatic children given zinc 50 mg/day for 8 weeks, blood zinc rose and clinical symptoms and lung function improved versus placebo.

Trust comment: Randomized double-blind placebo-controlled trial with objective spirometry and clear biochemical change, moderate sample size.

Study Details

PMID:24960516
Participants:284
Impact:+~67 µg/dL (from ~62 to 129 µg/dL in zinc group vs ~61 to 63 µg/dL in controls)
Trust score:4/5

In a 12-month weight-loss trial, diets with differing zinc content maintained normal zinc status; higher-protein diet improved some iron markers but zinc did not change between groups.

Trust comment: Randomized diet trial with small completer sample (n=36) and objective biomarkers, but limited sample size reduces precision.

Study Details

PMID:24231018
Participants:36
Impact:no longitudinal between-diet difference
Trust score:3/5

One-month double-blind RCT in ICU nurses: zinc supplementation increased serum zinc and improved overall sleep quality and some PSQI subscales.

Trust comment: Double-blind RCT with objective serum zinc and validated sleep questionnaire but small sample and subjective primary outcome.

Study Details

PMID:29241421
Participants:53
Impact:increased in zinc group (end of study vs control)
Trust score:3/5

Six months of zinc‑fortified rice increased serum zinc, lowered zinc deficiency prevalence, and (for NutriRice) increased serum folate in Cambodian schoolchildren.

Trust comment: Large double-blind cluster-RCT with biochemical outcomes and appropriate statistical methods; high external validity for similar settings.

Study Details

PMID:31756911
Participants:1667
Impact:+0.98 µmol/L (URO), +0.85 µmol/L (URN), +1.40 µmol/L (NutriRice) vs placebo at endline
Trust score:5/5

In children with chronic kidney disease, daily zinc (15 vs 30 mg) for up to 12 months led to a small but significant increase in body mass and some anthropometric measures, especially with 30 mg/day; serum zinc, albumin and CRP showed no consistent improvement.

Trust comment: Randomized multicenter trial in humans with objective anthropometric and biochemical measures, but small sample, partial masking, no placebo control group, and 27% attrition reduces certainty.

Study Details

PMID:31694220
Participants:35
Impact:no significant change from baseline
Trust score:3/5

Randomized placebo-controlled trial in hemodialysis patients; zinc raised serum zinc and produced a non-significant fall in CRP.

Trust comment: Randomized double-blind placebo-controlled trial but small sample (n=55), so moderate confidence.

Study Details

PMID:19541504
Participants:55
Impact:+31.0 μg/dL (from 57.4 to 88.4 μg/dL)
Trust score:4/5

Substudy of AREDS (717 participants): 5 years of zinc oxide supplementation increased serum zinc (~17% median) versus ~2% in non-zinc groups, with no significant long-term effects on hematocrit, copper, or lipids.

Trust comment: High-quality long-term randomized trial substudy with clear objective biomarker outcomes and large sample for this analysis.

Study Details

PMID:11925463
Participants:717
Impact:median +17% with zinc supplementation vs +2% without (p<0.001)
Trust score:5/5

Weekly zinc supplementation increased serum zinc in infants; iron indicators were unchanged and serum copper decreased with zinc or iron supplementation.

Trust comment: Double‑blind, randomized community trial with clear biochemical endpoints and adequate group sizes.

Study Details

PMID:16140896
Participants:333
Impact:Increased in groups receiving weekly zinc (greater increase in those with low baseline Zn)
Trust score:4/5

Postmenopausal osteoporotic women took zinc or placebo for 60 days; zinc raised serum zinc but did not change serum calcium.

Trust comment: Randomized double-blind placebo-controlled RCT with clear biochemical endpoints but small sample (n=60).

Study Details

PMID:23879079
Participants:60
Impact:+50 µg/dL (increased to 120.5 from 70.5 µg/dL after 60 days)
Trust score:4/5

Weekly or daily micronutrient supplements including zinc raised hemoglobin, serum zinc, and retinol versus placebo; growth improved only in children who were stunted at baseline.

Trust comment: Double-blind placebo-controlled trial with clear biomarker improvements and subgroup growth benefit; moderate sample size.

Study Details

PMID:9925127
Participants:163
Impact:increased in both daily and weekly groups vs placebo (P < 0.001)
Trust score:4/5

In formula-fed infants, early versus later introduction of complementary foods did not affect serum zinc concentrations or zinc status at 12, 24, or 36 months.

Trust comment: Randomized prospective trial with completed follow-up in majority of participants and direct biochemical measures of zinc status.

Study Details

PMID:11320951
Participants:133
Impact:no difference between early and late complementary feeding groups at 12, 24, 36 months
Trust score:4/5

In a 6-week double-blind RCT, curcumin (both forms) increased serum zinc and the zinc-to-copper ratio in people with metabolic syndrome.

Trust comment: Double-blind randomized clinical trial with clear measurement of serum trace elements in 120 participants.

Study Details

PMID:30020812
Participants:120
Impact:increase (significant, p < 0.001)
Trust score:4/5

Zinc-deficient nursing home residents received 30 mg/day zinc or placebo for 3 months to assess serum zinc and T cell immune measures.

Trust comment: Randomized double-blind placebo-controlled trial with clear biochemical and immune endpoints but small sample of zinc-deficient subset.

Study Details

PMID:26817502
Participants:31
Impact:mean change higher by 16% in zinc group vs placebo (p=0.007, adjusted)
Trust score:4/5

Zinc given to children with severe malnutrition led to biochemical zinc recovery, higher albumin and improved blood parameters, and fewer deaths compared with controls.

Trust comment: Large randomized double-blind controlled trial in 300 children with objective biochemical and clinical endpoints, though exact effect sizes for some outcomes are not reported.

Study Details

PMID:14725412
Participants:300
Impact:increase detected by day 60 post-discharge
Trust score:4/5

Between 2002 and 2012 zinc status in rural Chinese schoolchildren improved markedly (higher serum zinc, lower prevalence of deficiency and stunting).

Trust comment: Large, population-based survey using established WHO/UNICEF/IAEA/IZiNCG indicators across two time points, providing robust observational trends.

Study Details

PMID:28101714
Participants:3407
Impact:increase from 718.2 µg/L (2002) to 846.8 µg/L (2012)
Trust score:4/5

Infants given 3 mg/day zinc showed higher hair zinc but no significant improvements in weight or length growth over 6 months.

Trust comment: Small randomized double-blind trial with objective biomarker changes (hair zinc) but limited sample size and no growth benefit demonstrated.

Study Details

PMID:18560697
Participants:31
Impact:No significant change
Trust score:3/5

Zinc supplementation restored serum zinc levels and reduced some treatment side effects but did not change virologic response to interferon/ribavirin.

Trust comment: Randomized study but small sample size; biochemical and tolerability endpoints improved while virologic efficacy unchanged.

Study Details

PMID:15904908
Participants:40
Impact:restored/increased from depressed levels during IFN/ribavirin therapy
Trust score:3/5

Randomized trial in 290 preschoolers: vitamin A + zinc improved height gains; multiple micronutrients yielded greater hemoglobin increases; serum zinc rose most in the vitamin A+zinc group.

Trust comment: Well-sized randomized trial with multiple arms and biologic endpoints, though full methodological details (blinding etc.) are limited in the summary.

Study Details

PMID:22374555
Participants:290
Impact:increased in all groups; greatest increase in vitamin A + zinc group (significant)
Trust score:4/5

Women using contraceptives had lower mean serum zinc (and some other trace elements) compared with non-users; reductions correlated with duration of use.

Trust comment: Cross-sectional study (n=150) with statistically significant differences but observational design limits causal inference.

Study Details

PMID:22224344
Participants:150
Impact:decreased (contraceptive users vs controls; p<0.01)
Trust score:3/5

Subsample (n=740) from a randomized antenatal trial in rural Nepal: multiple micronutrient supplementation reduced the prevalence of vitamin D deficiency though mean serum 25‑hydroxyvitamin D concentrations were unchanged between first and third trimester.

Trust comment: Randomized controlled trial with biochemical endpoints in a large subsample (n=740); results are specific and well-reported.

Study Details

PMID:16600929
Participants:740
Impact:no improvement with folic acid + iron + zinc
Trust score:4/5

Very low birth weight infants received fortified human milk with or without trace elements; study focused on multiple minerals and growth, not iodine effects.

Trust comment: Prospective randomized trial in VLBW infants with objective biochemical measures but modest sample size and short follow-up.

Study Details

PMID:15448423
Participants:62
Impact:No significant difference at 6 weeks (zinc deficiency rare)
Trust score:4/5

Three-month randomized trial of antihypertensive monotherapy showing diuretics, ACE‑inhibitors and calcium‑antagonists altered zinc status (increased zincuria and reduced serum/erythrocyte zinc); not investigating calcium supplementation or calcium outcomes.

Trust comment: Well-characterized prospective trial with careful mineral measurements and dietary control, though allocation details limit generalizability.

Study Details

PMID:30208601
Participants:98
Impact:decreased after ACE inhibitor therapy (significant)
Trust score:4/5

Zinc-containing fortifications (MNPs or fortified CSB) increased serum zinc in moderately malnourished children; one MNP formulation without zinc decreased serum zinc.

Trust comment: Cluster randomized controlled trial with good adherence and objective serum measures, but limitations include non–trace-element vacutainers and retrospective registration.

Study Details

PMID:36121865
Participants:276
Impact:CSB-MNP-A: +18.7 μg/dL; CSB-MNP-C: +9.4 μg/dL; CSB (control): +11.8 μg/dL; CSB-MNP-B (no zinc): -4.9 μg/dL (pre-post changes)
Trust score:4/5

In EDTA chelation-treated patients, urinary magnesium excretion decreased (indicating magnesium retention) while blood lead fell substantially.

Trust comment: Double-blind placebo-controlled trial (n=60) with direct biochemical measures showing large changes in metal excretion and serum levels.

Study Details

PMID:8969629
Participants:60
Impact:decreased by ~34% after treatment
Trust score:4/5

Daily 5 mg zinc raised serum zinc overall and improved weight gain and reduced lower respiratory infection incidence in infants who were zinc-deficient at baseline.

Trust comment: Large randomized placebo-controlled trial with objective biochemical and clinical outcomes and clear subgroup effects.

Study Details

PMID:12450909
Participants:301
Impact:+2.6 μmol/L at 24 wk (13.3 vs 10.7 μmol/L; P < 0.001)
Trust score:5/5

Weekly zinc (70 mg) increased serum zinc by 16% in preschool children selected for low/marginal nutrient status; growth effects were driven by vitamin A, not zinc.

Trust comment: Randomized factorial study but small selected sample (n=43 completed) limits generalizability; objective biomarker change for zinc robust.

Study Details

PMID:10376776
Participants:43
Impact:↑ 16% with zinc supplementation (P<0.001)
Trust score:3/5

In obese postmenopausal women, multistrain probiotic supplementation altered some iron-status markers and produced small, dose-dependent changes in serum zinc (increase at low dose, decrease at high dose) compared with baseline.

Trust comment: Randomized trial with 30 subjects per arm reporting serum zinc changes as secondary/associated outcomes; moderate quality but zinc was not the primary intervention target.

Study Details

PMID:31384878
Participants:90
Impact:LD group: increased vs baseline; HD group: decreased vs baseline (within-group changes reported)
Trust score:4/5

Two weeks of zinc syrup (20 mg/day) in children with persistent diarrhoea shortened recovery time in underweight kids and prevented weight and serum zinc loss.

Trust comment: Randomized double-blind controlled trial with clinically meaningful outcomes in 190 high-risk children; subgroup effects reported.

Study Details

PMID:9894821
Participants:190
Impact:maintained in zinc group (13.4 → 13.6 μmol/L) vs decreased in control (13.6 → 11.8 μmol/L); P<0.03
Trust score:4/5

Daily 25 mg zinc for 3 weeks raised serum zinc but did not restore night vision by itself; it appeared to help vitamin A restore night vision in women with low baseline zinc.

Trust comment: Randomized, double-blind trial with 202 participants and objective measures; subgroup effect and borderline p-value limit certainty.

Study Details

PMID:11382658
Participants:202
Impact:increased (post-treatment)
Trust score:4/5

ACE inhibitor therapy altered zinc parameters: serum zinc fell and urinary zinc rose during treatment.

Trust comment: Randomized, double-blind comparison of ACE inhibitors in 31 hypertensive patients; small sample but measurements direct and reported with statistics.

Study Details

PMID:8966143
Participants:31
Impact:decrease during ACEI therapy (ZnS significantly lowered)
Trust score:3/5

Two multicenter studies: a double-blind RCT (NPC-02 zinc acetate, n≈56 efficacy-set) and a dose-adjustment study (n=43); zinc acetate significantly raised serum zinc and dose-dependently increased concentrations with acceptable safety.

Trust comment: Multicenter randomized placebo-controlled trial + dose-adjustment study with objective biochemical endpoints and transparent safety reporting; moderate sample but high internal validity.

Study Details

PMID:31392541
Participants:99
Impact:mean increase ~22.4 μg/dL greater vs placebo at week 8
Trust score:4/5

Cross-sectional analysis of serum copper, selenium and zinc versus Montenegro skin test (MST) diameter in vaccinated volunteers.

Trust comment: Moderate-quality observational study (n=172) with appropriate assays but correlational design cannot establish causality.

Study Details

PMID:17980395
Participants:172
Impact:Reported mean zinc 999.2 ± 366 μg/L with no significant relation to MST size
Trust score:3/5

In children with shigellosis, 14 days of adjunct zinc increased serum zinc, improved antibody seroconversion and increased circulating B-cell/plasma-cell proportions.

Trust comment: Double-blind placebo-controlled trial in malnourished children showing immunologic improvements with zinc adjunct therapy.

Study Details

PMID:15699240
Participants:56
Impact:increase (significant)
Trust score:4/5

Pregnant women given different iron doses (one tablet contained added zinc) showed no significant between-group differences in serum zinc during pregnancy.

Trust comment: Randomized comparison of iron dosing with multinutrient tablet including zinc; not primarily a zinc intervention so conclusions about zinc effects are limited.

Study Details

PMID:11787984
Participants:67
Impact:no significant difference between 100 mg and 15 mg iron groups (15 mg tablet contained 10 mg zinc)
Trust score:3/5

Dietary changes over 2 years were associated with altered serum zinc; in the low-fat group, decreasing fats and decreasing sweets/snacks predicted higher serum zinc.

Trust comment: Controlled dietary intervention with measured biomarkers, but associations are observational within the trial and not a zinc supplementation intervention.

Study Details

PMID:25531289
Participants:231
Impact:increase associated with decreased fats and decreased sweets/snacks in low-fat group (β ≈ -0.575, p=0.022 at 12 mo; β ≈ -0.570, p=0.027 at 24 mo)
Trust score:3/5

T cell proliferation

1 evidences

Zinc-deficient nursing home residents received 30 mg/day zinc or placebo for 3 months to assess serum zinc and T cell immune measures.

Trust comment: Randomized double-blind placebo-controlled trial with clear biochemical and immune endpoints but small sample of zinc-deficient subset.

Study Details

PMID:26817502
Participants:31
Impact:significant increase in stimulated T cell proliferation (driven by increased T cell numbers)
Trust score:4/5

peripheral T cell number

1 evidences

Zinc-deficient nursing home residents received 30 mg/day zinc or placebo for 3 months to assess serum zinc and T cell immune measures.

Trust comment: Randomized double-blind placebo-controlled trial with clear biochemical and immune endpoints but small sample of zinc-deficient subset.

Study Details

PMID:26817502
Participants:31
Impact:significant increase (zinc group)
Trust score:4/5

basal serum zinc

1 evidences

Healthy 8–9-year-old children received oral and IV zinc over 3 months; growth-related hormones and enzymes were measured acutely and across the study.

Trust comment: Triple-blind RCT with clear biomarker changes but small sample and short duration limit generalizability.

Study Details

PMID:25759961
Participants:40
Impact:significant increase after supplementation (p < 0.0001)
Trust score:3/5

alkaline phosphatase (ALP)

1 evidences

Healthy 8–9-year-old children received oral and IV zinc over 3 months; growth-related hormones and enzymes were measured acutely and across the study.

Trust comment: Triple-blind RCT with clear biomarker changes but small sample and short duration limit generalizability.

Study Details

PMID:25759961
Participants:40
Impact:significant increase (p = 0.027)
Trust score:3/5

IGF1 and IGFBP3

1 evidences

Healthy 8–9-year-old children received oral and IV zinc over 3 months; growth-related hormones and enzymes were measured acutely and across the study.

Trust comment: Triple-blind RCT with clear biomarker changes but small sample and short duration limit generalizability.

Study Details

PMID:25759961
Participants:40
Impact:plasma IGF1 and IGFBP3 increased significantly during zinc administration (IGF1 p=0.0468; IGFBP3 p<0.0001)
Trust score:3/5

urinary zinc excretion

8 evidences

6 months of 15–30 mg/day zinc raised serum and urinary zinc with no major overall adverse effects on iron, copper status or lipids, though 30 mg/day showed some age/sex‑dependent changes.

Trust comment: Large randomized double‑blind study (n=387) with dose arms and 6‑month follow‑up; well conducted though subgroup signals noted.

Study Details

PMID:17313720
Participants:387
Impact:significant increase with supplementation
Trust score:4/5

In EDTA chelation-treated patients, urinary magnesium excretion decreased (indicating magnesium retention) while blood lead fell substantially.

Trust comment: Double-blind placebo-controlled trial (n=60) with direct biochemical measures showing large changes in metal excretion and serum levels.

Study Details

PMID:8969629
Participants:60
Impact:~25-fold increase after first infusion (EDTA vs control)
Trust score:4/5

ACE inhibitor therapy altered zinc parameters: serum zinc fell and urinary zinc rose during treatment.

Trust comment: Randomized, double-blind comparison of ACE inhibitors in 31 hypertensive patients; small sample but measurements direct and reported with statistics.

Study Details

PMID:8966143
Participants:31
Impact:increase during ACEI therapy (ZnU increased)
Trust score:3/5

Three-month randomized trial of antihypertensive monotherapy showing diuretics, ACE‑inhibitors and calcium‑antagonists altered zinc status (increased zincuria and reduced serum/erythrocyte zinc); not investigating calcium supplementation or calcium outcomes.

Trust comment: Well-characterized prospective trial with careful mineral measurements and dietary control, though allocation details limit generalizability.

Study Details

PMID:30208601
Participants:98
Impact:increased after diuretics (significant)
Trust score:4/5

A randomized controlled trial in iron-depleted schoolchildren found that NaFeEDTA-fortified wheat improved iron status but did not change urinary zinc excretion after 7 months.

Trust comment: Randomized controlled trial with adequate sample and clear biomarker outcomes for urinary zinc and iron status.

Study Details

PMID:23156119
Participants:179
Impact:no significant difference (iron group median 38.4 μg/dL vs control 33.1 μg/dL)
Trust score:4/5

48 surgical patients randomized to low-dose rhGH or placebo; rhGH decreased urinary zinc excretion and improved zinc balance and utilization but raised mean blood glucose transiently postoperatively.

Trust comment: Randomized clinical setting but small surgical sample and primary intervention was growth hormone (indirect effects on zinc).

Study Details

PMID:18069770
Participants:48
Impact:decreased in rhGH group (P < 0.05)
Trust score:3/5

Non-anemic infants received iron+cu with or without 10 mg zinc daily from 6–18 months; blood and urine minerals tracked at multiple timepoints.

Trust comment: Large randomized controlled trial with repeated measures and high compliance, supporting biochemical effects of daily zinc supplementation.

Study Details

PMID:24103510
Participants:251
Impact:increased in zinc group at 12 months only
Trust score:4/5

Antihypertensive monotherapy was associated with decreased serum zinc and increased urinary zinc; an optimal-mineral diet restored serum zinc.

Trust comment: Controlled clinical monitoring in a small sample shows plausible drug–mineral interactions but is limited by sample size and short follow-up.

Study Details

PMID:24452943
Participants:45
Impact:significant increase after treatment
Trust score:3/5

hemoglobin

8 evidences

Children aged 1–5 years received 10 mg/day zinc for 4 months; zinc normalized serum zinc and improved hemoglobin but did not change growth measures.

Trust comment: Blinded randomized clinical trial with small sample (n=58); biochemical improvements clear but anthropometric responses absent.

Study Details

PMID:16738738
Participants:58
Impact:Mean hemoglobin increased in zinc group (P=0.002)
Trust score:3/5

Adding 15 mg zinc to prenatal iron+folate did not alter hemoglobin or ferritin changes during pregnancy.

Trust comment: Large randomized double-masked trial with measured hematologic outcomes supports reliable null finding for added zinc.

Study Details

PMID:10731503
Participants:645
Impact:no significant difference by supplement type (iron+folate with vs without zinc)
Trust score:4/5

1125 adolescent girls received a fortified beverage for up to 12 months; fortification (including zinc) improved hemoglobin, ferritin, retinol, and short-term growth measures.

Trust comment: Large randomized double-blind placebo-controlled trial with objective biochemical and anthropometric outcomes, but multinutrient product means effects cannot be attributed solely to zinc.

Study Details

PMID:17709456
Participants:1125
Impact:increased at 6 months (significant, P<0.01)
Trust score:4/5

Reducing phytate in weaning cereals produced little long-term effect on infants' iron or zinc status over 6 months.

Trust comment: Large randomized intervention with good follow-up, but effects on zinc status were minimal.

Study Details

PMID:12816787
Participants:267
Impact:slightly higher in phytate-reduced cereal vs formula group (120 g/L vs 117 g/L)
Trust score:4/5

In a 3-month randomized double-blind trial, daily 30 mg iron plus 30 mg zinc improved hemoglobin, total body iron and serum zinc versus placebo in women of childbearing age.

Trust comment: Randomized double-blind trial with moderate sample size and clinically relevant biochemical outcomes.

Study Details

PMID:25582309
Participants:81
Impact:significant increase vs placebo
Trust score:4/5

Non-anemic infants received iron+cu with or without 10 mg zinc daily from 6–18 months; blood and urine minerals tracked at multiple timepoints.

Trust comment: Large randomized controlled trial with repeated measures and high compliance, supporting biochemical effects of daily zinc supplementation.

Study Details

PMID:24103510
Participants:251
Impact:evidence of improved hemoglobin at 18 months (trend, p = 0.09)
Trust score:4/5

Fortified biscuits (including iodine) increased iodine and other micronutrient status and reduced anemia in primary schoolchildren and improved deworming effectiveness.

Trust comment: Large randomized, double-blind, placebo-controlled trial with clear biochemical outcomes and robust effect estimates.

Study Details

PMID:19321576
Participants:510
Impact:+1.87 g/L (95% CI: 0.78 to 2.96)
Trust score:5/5

Six-month RCT in Vietnamese infants testing daily or weekly multiple micronutrients (including a small zinc dose) vs placebo; growth and blood micronutrients measured.

Trust comment: Large randomized, double-blind trial with clear biomarker and growth outcomes, but zinc was one component of a multi-micronutrient supplement and dose appears small.

Study Details

PMID:15735111
Participants:306
Impact:+16.4 g/L change in DMM vs +8.6 g/L in placebo (6 mo)
Trust score:4/5

cold symptom duration

1 evidences

Children/adolescents with early cold symptoms received zinc gluconate lozenges or placebo; symptom duration and adverse events were recorded.

Trust comment: Large randomized double-masked placebo-controlled trial with clear null primary outcome and reported adverse events.

Study Details

PMID:9643859
Participants:249
Impact:no significant difference (median 9 days in both groups; P = .71)
Trust score:4/5

adverse effects — bad taste

1 evidences

Children/adolescents with early cold symptoms received zinc gluconate lozenges or placebo; symptom duration and adverse events were recorded.

Trust comment: Large randomized double-masked placebo-controlled trial with clear null primary outcome and reported adverse events.

Study Details

PMID:9643859
Participants:249
Impact:more frequent in zinc group (60.2% vs 37.9%, p=0.001)
Trust score:4/5

adverse effects — nausea/mouth discomfort/diarrhea

1 evidences

Children/adolescents with early cold symptoms received zinc gluconate lozenges or placebo; symptom duration and adverse events were recorded.

Trust comment: Large randomized double-masked placebo-controlled trial with clear null primary outcome and reported adverse events.

Study Details

PMID:9643859
Participants:249
Impact:higher in zinc group (nausea 29.3% vs 16.1%, p=0.01; mouth/tongue discomfort 36.6% vs 24.2%, p=0.03; diarrhea 10.6% vs 4.0%, p=0.05)
Trust score:4/5

diarrhea incidence

7 evidences

Daily 10 mg zinc for 7 months reduced diarrhea incidence and persistent diarrhea in young Guatemalan children; no clear effect on respiratory infections.

Trust comment: Randomized double-blind community trial with daily morbidity surveillance; moderate sample size but rigorous design.

Study Details

PMID:9164774
Participants:89
Impact:-22% median incidence
Trust score:4/5

School lunch seasoning fortified with multiple micronutrients (including 50 μg iodine per serving) reduced respiratory and diarrheal morbidity and slightly improved a visual recall test, but did not change growth.

Trust comment: Large cluster RCT with meaningful morbidity and short-term cognitive endpoints, but fortification included multiple micronutrients.

Study Details

PMID:18541560
Participants:569
Impact:reduced (rate ratio 0.38; 95% CI: 0.16, 0.90)
Trust score:4/5

Weekly oral zinc reduced pneumonia episodes and slightly reduced diarrhea incidence and reduced deaths in young children in this urban Bangladesh trial.

Trust comment: Large randomized trial with meaningful clinical endpoints and mortality benefit, though notable withdrawals may affect generalizability.

Study Details

PMID:16168782
Participants:1621
Impact:-6% (1881 vs 2407 cases; RR 0.94; 95% CI 0.88–0.99)
Trust score:4/5

Daily zinc (3–10 mg) for 6 months raised plasma zinc in a dose-dependent manner and reduced diarrhea incidence by ~21–42% without adverse effects on copper or iron markers.

Trust comment: Randomized, double-masked, community-based trial with adequate sample size and clear outcomes.

Study Details

PMID:18326612
Participants:631
Impact:-21% to -42% (statistically significant)
Trust score:5/5

Weekly zinc supplementation in young children reduced diarrheal illness and was feasible to deliver in the community.

Trust comment: Large randomized double-blind community trial with extensive follow-up and good operational data supports high trust.

Study Details

PMID:17414392
Participants:1712
Impact:decreased (significantly fewer episodes during supplementation period)
Trust score:5/5

Children receiving combined vitamin A and zinc had fewer malaria and fever episodes, lower diarrhea incidence, and reduced anemia compared with placebo over six months.

Trust comment: Randomized double-blind trial with meaningful clinical outcomes, though baseline imbalances and combined supplementation (vitamin A + zinc) limit attribution to zinc alone.

Study Details

PMID:18237394
Participants:148
Impact:decreased (52.7% to 28.3%, p = 0.002)
Trust score:4/5

In children treated for acute diarrhea, 5 days of zinc was as effective as 10 days at preventing subsequent diarrhea over 3 months.

Trust comment: Large randomized, community double-blind trial with daily supervision and adequate follow-up; compares two zinc regimens rather than zinc vs no zinc.

Study Details

PMID:21147907
Participants:1622
Impact:no significant difference; mean episodes 1.08 (5-d) vs 1.02 (10-d) over 90 d (P=0.35)
Trust score:4/5

zinc absorption (with enzymatic dephytinization)

1 evidences

Study of 2–10 y Nigerian children showed meals reduce zinc absorption and enzymatic dephytinization of maize porridge doubled zinc absorption from the meal.

Trust comment: Small, controlled study using stable isotopes and direct absorption measures but limited sample size.

Study Details

PMID:19321589
Participants:34
Impact:+101% (relative increase from meal; P<0.001)
Trust score:3/5

zinc absorption (meal vs no meal)

1 evidences

Study of 2–10 y Nigerian children showed meals reduce zinc absorption and enzymatic dephytinization of maize porridge doubled zinc absorption from the meal.

Trust comment: Small, controlled study using stable isotopes and direct absorption measures but limited sample size.

Study Details

PMID:19321589
Participants:34
Impact:lower with meal (16.2% vs 63.4%)
Trust score:3/5

calcium absorption (meal effect)

1 evidences

Study of 2–10 y Nigerian children showed meals reduce zinc absorption and enzymatic dephytinization of maize porridge doubled zinc absorption from the meal.

Trust comment: Small, controlled study using stable isotopes and direct absorption measures but limited sample size.

Study Details

PMID:19321589
Participants:34
Impact:increased with meal (61.3% vs 27.8%)
Trust score:3/5

percentage zinc absorption

1 evidences

After RYGBP surgery zinc absorption and several zinc status markers declined despite higher supplemental zinc intakes; absorption dropped sharply at 6 months.

Trust comment: Randomized supplementation groups with 18-month follow-up and objective biochemical absorption measures; moderate sample and good follow-up (56 completers).

Study Details

PMID:21865332
Participants:56
Impact:decreased from 32.3% pre-op to 13.6% at 6 mo and 21% at 18 mo
Trust score:4/5

rapidly exchangeable zinc pool size

1 evidences

After RYGBP surgery zinc absorption and several zinc status markers declined despite higher supplemental zinc intakes; absorption dropped sharply at 6 months.

Trust comment: Randomized supplementation groups with 18-month follow-up and objective biochemical absorption measures; moderate sample and good follow-up (56 completers).

Study Details

PMID:21865332
Participants:56
Impact:decreased after RYGBP
Trust score:4/5

DNA strand breaks (comet tail moment)

1 evidences

17-day randomized placebo-controlled trial: 20 mg/day zinc reduced blood cell DNA strand breaks (comet assay) despite no significant change in plasma zinc.

Trust comment: Randomized placebo-controlled trial with blinded assay and clear biomarker change, though short duration and small sample.

Study Details

PMID:25491347
Participants:40
Impact:decreased from 39.7 to 30.0 (≈-24%; P<0.005)
Trust score:4/5

time to resolution of respiratory signs

1 evidences

Large RCT in children with severe pneumonia found adjunctive zinc did not change time to resolution of respiratory signs or treatment failure.

Trust comment: Large randomized controlled trial (225 per arm) with clinical endpoints; negative primary result but good design and sample size.

Study Details

PMID:24429536
Participants:450
Impact:no effect of zinc supplementation
Trust score:4/5

treatment failure

2 evidences

Large RCT in children with severe pneumonia found adjunctive zinc did not change time to resolution of respiratory signs or treatment failure.

Trust comment: Large randomized controlled trial (225 per arm) with clinical endpoints; negative primary result but good design and sample size.

Study Details

PMID:24429536
Participants:450
Impact:no effect of zinc supplementation
Trust score:4/5

In infants with probable serious bacterial infection, adding 10 mg zinc daily to antibiotics reduced treatment failure compared with placebo.

Trust comment: Large randomized double-blind placebo-controlled multicenter trial with clinically important primary outcome and intention-to-treat analysis.

Study Details

PMID:22656335
Participants:700
Impact:10% (zinc) vs 17% (placebo); absolute risk reduction 6.8%; relative risk reduction 40% (p=0.011)
Trust score:5/5

association of baseline zinc with recovery speed

1 evidences

Large RCT in children with severe pneumonia found adjunctive zinc did not change time to resolution of respiratory signs or treatment failure.

Trust comment: Large randomized controlled trial (225 per arm) with clinical endpoints; negative primary result but good design and sample size.

Study Details

PMID:24429536
Participants:450
Impact:higher basal zinc associated with faster resolution of chest indrawing (observational)
Trust score:4/5

sleep quality (PSQI total score)

1 evidences

One-month double-blind RCT in ICU nurses: zinc supplementation increased serum zinc and improved overall sleep quality and some PSQI subscales.

Trust comment: Double-blind RCT with objective serum zinc and validated sleep questionnaire but small sample and subjective primary outcome.

Study Details

PMID:29241421
Participants:53
Impact:improved (intervention group score decreased vs control)
Trust score:3/5

subjective sleep quality and sleep latency

1 evidences

One-month double-blind RCT in ICU nurses: zinc supplementation increased serum zinc and improved overall sleep quality and some PSQI subscales.

Trust comment: Double-blind RCT with objective serum zinc and validated sleep questionnaire but small sample and subjective primary outcome.

Study Details

PMID:29241421
Participants:53
Impact:improved in zinc group (significant)
Trust score:3/5

total cholesterol

1 evidences

Randomized double-blind placebo-controlled trial in 60 adults with moderate hypercholesterolemia; an 8-week nutraceutical containing bergamot/artichoke/Q10 and zinc improved lipids, inflammation markers and endothelial reactivity versus placebo.

Trust comment: Randomized, double-blind placebo-controlled trial with complete follow-up (n=60); modest sample size limits precision but design is strong.

Study Details

PMID:35631240
Participants:60
Impact:significant decrease vs placebo
Trust score:4/5

neuropsychologic performance

1 evidences

In a 10-week trial in Chinese schoolchildren, zinc plus other micronutrients improved neuropsychologic performance and growth more than zinc or micronutrients alone; plasma zinc rose after micronutrient treatments.

Trust comment: Large double-blind controlled trial with clear outcomes, though 10-week duration is relatively short.

Study Details

PMID:9701162
Participants:740
Impact:improved most with zinc + micronutrients
Trust score:4/5

growth (knee height)

1 evidences

In a 10-week trial in Chinese schoolchildren, zinc plus other micronutrients improved neuropsychologic performance and growth more than zinc or micronutrients alone; plasma zinc rose after micronutrient treatments.

Trust comment: Large double-blind controlled trial with clear outcomes, though 10-week duration is relatively short.

Study Details

PMID:9701162
Participants:740
Impact:improved most with zinc + micronutrients
Trust score:4/5

anemia prevalence

6 evidences

380 Cambodian schoolchildren ate fortified or placebo rice for 6 months; fortified rice altered gut microbiota and improved some micronutrient/inflammation markers.

Trust comment: Large double-blind cluster-RCT subsample with objective biochemical and sequencing outcomes; intervention combined multiple micronutrients so attribution to zinc alone is limited.

Study Details

PMID:38890302
Participants:380
Impact:decreased with UR-improved fortified rice (significant reduction)
Trust score:4/5

Double-masked, placebo-controlled 100-day trial in 100 anemic schoolchildren comparing a multi‑fortified juice (including zinc) vs non‑fortified juice; supervised administration and deworming were done.

Trust comment: Randomized, double-masked, placebo-controlled trial with supervised intake but moderate sample size (n=100); multi‑nutrient fortification complicates attributing effects solely to zinc.

Study Details

PMID:22094838
Participants:100
Impact:Fortified: 100% → 13%; Non‑fortified: 100% → 40% (both reduced, greater reduction in fortified group)
Trust score:4/5

In Indonesian infants, 6 months of zinc and/or iron supplementation reduced zinc deficiency and anemia prevalence, but combined iron+zinc was less effective than iron alone at reducing anemia; no effect on growth.

Trust comment: Large randomized double-blind placebo-controlled trial in infants; interaction effects reported increase complexity but overall high quality.

Study Details

PMID:11694609
Participants:478
Impact:reduced; iron+zinc reduced anemia by ~20% vs iron alone ~38% reduction
Trust score:4/5

In a 7-month cluster-RCT of fortified rice in Burundian schoolchildren, the intervention did not significantly increase hemoglobin or reduce anemia prevalence.

Trust comment: Large cluster-randomized controlled trial with appropriate outcomes, though high infection burden and formulation issues limited effect detection.

Study Details

PMID:26612421
Participants:904
Impact:no significant reduction
Trust score:4/5

Pooled data from four randomized trials in SE Asia showed combined iron+zinc reduced anemia and zinc deficiency but was less effective than single-nutrient supplements due to interactions.

Trust comment: Large pooled analysis of four randomized, placebo-controlled, double-blind trials (n=2468) across multiple countries providing strong evidence with clear statistical results.

Study Details

PMID:17237328
Participants:2468
Impact:combined iron+zinc reduced anemia prevalence by 21% (P<0.01) versus placebo
Trust score:5/5

Large cluster-randomized trial: daily micronutrient Sprinkles (included zinc) plus feeding education reduced anemia and iron deficiency and increased mean serum zinc during the intervention period.

Trust comment: Large cluster-randomized effectiveness trial with objective biomarker outcomes; effects on zinc and anemia did not persist beyond intervention.

Study Details

PMID:22801933
Participants:3112
Impact:-20.6% at 12 months
Trust score:4/5

zinc deficiency prevalence

10 evidences

Daily consumption of low-dose, highly bioavailable zinc-fortified filtered water increased children's blood zinc and reduced zinc deficiency but did not change diarrhea or growth.

Trust comment: Double-blind RCT with objective biochemical outcomes; modest sample size and limited power for clinical endpoints.

Study Details

PMID:26468121
Participants:277
Impact:significant reduction in Zn+filter group vs controls (P = 0.032)
Trust score:4/5

Six-month RCT in Vietnamese infants testing daily or weekly multiple micronutrients (including a small zinc dose) vs placebo; growth and blood micronutrients measured.

Trust comment: Large randomized, double-blind trial with clear biomarker and growth outcomes, but zinc was one component of a multi-micronutrient supplement and dose appears small.

Study Details

PMID:15735111
Participants:306
Impact:zinc deficiency still present in ~33% after 6 mo (no meaningful improvement)
Trust score:4/5

Pooled data from four randomized trials in SE Asia showed combined iron+zinc reduced anemia and zinc deficiency but was less effective than single-nutrient supplements due to interactions.

Trust comment: Large pooled analysis of four randomized, placebo-controlled, double-blind trials (n=2468) across multiple countries providing strong evidence with clear statistical results.

Study Details

PMID:17237328
Participants:2468
Impact:combined iron+zinc reduced zinc deficiency by 10% (P<0.05)
Trust score:5/5

In Indonesian infants, 6 months of zinc and/or iron supplementation reduced zinc deficiency and anemia prevalence, but combined iron+zinc was less effective than iron alone at reducing anemia; no effect on growth.

Trust comment: Large randomized double-blind placebo-controlled trial in infants; interaction effects reported increase complexity but overall high quality.

Study Details

PMID:11694609
Participants:478
Impact:significantly reduced with zinc supplementation
Trust score:4/5

Zinc-containing fortifications (MNPs or fortified CSB) increased serum zinc in moderately malnourished children; one MNP formulation without zinc decreased serum zinc.

Trust comment: Cluster randomized controlled trial with good adherence and objective serum measures, but limitations include non–trace-element vacutainers and retrospective registration.

Study Details

PMID:36121865
Participants:276
Impact:Decreased in CSB-MNP-A, CSB-MNP-C and CSB groups; increased in CSB-MNP-B
Trust score:4/5

Daily zinc supplementation did not reduce malaria episodes but increased plasma zinc and markedly reduced zinc deficiency.

Trust comment: Large randomized, double-blind trial with high adherence, prespecified analyses, and clinically measured endpoints.

Study Details

PMID:22131908
Participants:592
Impact:−52% (relative to placebo)
Trust score:5/5

Cross-sectional analysis found a high prevalence (31.3%) of biochemical zinc deficiency in healthy 1–3-year-old children in Western Europe.

Trust comment: Relatively large, multicenter sample with standardized assays, though cross-sectional design limits causal inference.

Study Details

PMID:34835970
Participants:278
Impact:31.3% (87/278) had serum Zn < 9.9 µmol/L
Trust score:4/5

Cross-sectional baseline survey of HIV-infected Ugandan children (1–5 y); measured serum zinc and associated factors.

Trust comment: Well-described cross-sectional analysis with clear laboratory methods and moderate sample size, but observational design limits causal inference.

Study Details

PMID:20858275
Participants:247
Impact:54.3% (134/247) had serum zinc <10 μmol/L
Trust score:3/5

380 Cambodian schoolchildren ate fortified or placebo rice for 6 months; fortified rice altered gut microbiota and improved some micronutrient/inflammation markers.

Trust comment: Large double-blind cluster-RCT subsample with objective biochemical and sequencing outcomes; intervention combined multiple micronutrients so attribution to zinc alone is limited.

Study Details

PMID:38890302
Participants:380
Impact:decreased with UR-original fortified rice (significant reduction)
Trust score:4/5

Daily low-dose MNP containing bioavailable iron and 2.5 mg zinc reduced iron and zinc deficiencies and modestly improved weight-for-age over 23 weeks.

Trust comment: Double-blind randomized controlled trial with clear biochemical endpoints, though zinc dose was low and some outcomes lack reported effect sizes.

Study Details

PMID:21178093
Participants:200
Impact:prevalence decrease of 11.8% (P<0.05)
Trust score:4/5

growth (anthropometry)

3 evidences

Randomized trial in young children comparing 10 mg/day zinc alone, zinc+multivitamins/minerals, or placebo for ~6 months; morbidity, growth, and plasma micronutrients measured.

Trust comment: Well-conducted randomized controlled trial with adequate sample and objective biomarker and morbidity outcomes; direct zinc supplementation arm provides high internal validity.

Study Details

PMID:14985222
Participants:246
Impact:no significant effects on growth
Trust score:5/5

In Indonesian infants, 6 months of zinc and/or iron supplementation reduced zinc deficiency and anemia prevalence, but combined iron+zinc was less effective than iron alone at reducing anemia; no effect on growth.

Trust comment: Large randomized double-blind placebo-controlled trial in infants; interaction effects reported increase complexity but overall high quality.

Study Details

PMID:11694609
Participants:478
Impact:no difference among groups (no growth improvement)
Trust score:4/5

Sprinkles and Foodlets improved infants' zinc status more than Drops, but there was no benefit for growth or vitamin A/D status.

Trust comment: Randomized trial with multiple supplement arms and biochemical outcomes, though context-specific to local diet.

Study Details

PMID:21750564
Participants:362
Impact:no significant differences across groups
Trust score:4/5

duration of diarrhoea

5 evidences

Double-blind RCT in 80 malnourished children: zinc syrup shortened diarrhoea, reduced stool output and ORS use and improved early recovery rates.

Trust comment: Double-blind RCT with clear positive clinical effects and appropriate statistics, though sample size is modest.

Study Details

PMID:11077932
Participants:80
Impact:70.4±10.0 h (zinc) vs 103.4±17.1 h (placebo); ~33 h shorter (p=0.0001)
Trust score:4/5

In Aboriginal children hospitalized with acute diarrhoea, zinc and/or vitamin A supplementation did not shorten diarrhoea duration or reduce re-admission rates compared with placebo.

Trust comment: Well-sized randomized factorial trial in the target population; conclusions limited to non-malnourished hospitalized children.

Study Details

PMID:15896183
Participants:392
Impact:no significant effect (median 3.0 days in supplemented and placebo groups)
Trust score:4/5

Adding oral zinc to usual care for infants with rotavirus reduced symptom durations, improved response rate, and lowered 3-month recurrence and severe-recurrence rates.

Trust comment: Randomized trial with modest sample (n=103) and positive clinical outcomes, but single-center and limited reporting details.

Study Details

PMID:27655538
Participants:103
Impact:shorter with zinc (P < 0.05)
Trust score:3/5

Children with cholera given 30 mg/day zinc recovered faster and had shorter diarrhoea and lower stool output than placebo.

Trust comment: Double-blind, randomized, placebo-controlled trial with clinically meaningful, statistically significant effects on diarrhoea outcomes.

Study Details

PMID:18184631
Participants:164
Impact:64.1 h (zinc) vs 72.8 h (placebo); −12% (p=0.028)
Trust score:5/5

Providing zinc for 14 days during diarrhoea in children reduced duration and incidence of diarrhoea and lowered child mortality in the community trial.

Trust comment: Large community cluster-randomized trial with clear, clinically important outcomes and robust effect sizes.

Study Details

PMID:12424162
Participants:8070
Impact:shorter (hazard ratio 0.76, 95% CI 0.65–0.90)
Trust score:5/5

re-admission for diarrhoeal illness

1 evidences

In Aboriginal children hospitalized with acute diarrhoea, zinc and/or vitamin A supplementation did not shorten diarrhoea duration or reduce re-admission rates compared with placebo.

Trust comment: Well-sized randomized factorial trial in the target population; conclusions limited to non-malnourished hospitalized children.

Study Details

PMID:15896183
Participants:392
Impact:no significant difference
Trust score:4/5

maternal plasma zinc concentration

2 evidences

Daily 25 mg zinc in pregnant women with lower baseline zinc was associated with higher infant birth weight and larger head circumference, especially in women with BMI <26.

Trust comment: Large randomized double-blind placebo-controlled trial with significant, clinically relevant infant outcome measures and subgroup effects reported.

Study Details

PMID:7629954
Participants:580
Impact:increased in zinc supplement group
Trust score:4/5

Daily 15 mg zinc during lactation raised maternal plasma zinc but did not alter the decline in milk zinc concentrations over time compared with placebo.

Trust comment: Randomized double-blind trial with moderate sample; population was adequately nourished so effects on milk in deficient populations remain unknown.

Study Details

PMID:7733024
Participants:71
Impact:higher in supplemented group (P = 0.05)
Trust score:4/5

milk zinc concentration

1 evidences

Daily 15 mg zinc during lactation raised maternal plasma zinc but did not alter the decline in milk zinc concentrations over time compared with placebo.

Trust comment: Randomized double-blind trial with moderate sample; population was adequately nourished so effects on milk in deficient populations remain unknown.

Study Details

PMID:7733024
Participants:71
Impact:declined over time in all subjects; no effect of supplementation
Trust score:4/5

dietary zinc intake

2 evidences

Providing red meat or fortified toddler milk raised dietary zinc intake modestly (~+0.7–0.8 mg/day) but did not change serum or hair zinc concentrations in toddlers over 20 weeks.

Trust comment: Randomized 20-week intervention with biomarker measurement and adequate sample size; dietary increases were small and did not translate to biochemical change.

Study Details

PMID:20980643
Participants:225
Impact:Meat: +0.8 mg/day (95% CI 0.5–1.1); FTMD: +0.7 mg/day (95% CI 0.2–1.1); Placebo: −0.5 mg/day (95% CI −0.8 to −0.2)
Trust score:4/5

In the BLISS trial, infants following a modified baby-led weaning approach had similar zinc intakes at 7 and 12 months and similar plasma zinc at 12 months compared with spoon-fed controls.

Trust comment: Randomized controlled design with community sample and biochemical outcomes; intervention included modifications that may limit generalizability to unmodified BLW.

Study Details

PMID:29803269
Participants:206
Impact:no significant difference at 7 or 12 months (medians ~3.5 mg/day at 7 mo, ~4.4 mg/day at 12 mo)
Trust score:4/5

zinc absorptive efficiency

2 evidences

Crossover feeding study in women showed lower zinc absorption and a small drop in plasma zinc on a lactoovovegetarian diet compared with an omnivorous diet.

Trust comment: Controlled crossover feeding study with direct isotopic absorption measures in 21 women; small sample but strong design for absorption outcomes.

Study Details

PMID:9497185
Participants:21
Impact:21% reduction with lactoovovegetarian diet
Trust score:4/5

Healthy adults adjusted intestinal zinc absorption when dietary zinc was low and diets were low in phytate; some zinc-status biomarkers did not change.

Trust comment: Controlled human feeding experiments using radiotracers (n=109) provide direct, reliable measures of zinc absorption.

Study Details

PMID:18469257
Participants:109
Impact:Up-regulated to as high as 92% on low-zinc (<11 mg/d), low-phytate diets
Trust score:4/5

relation of absorptive efficiency to dietary zinc

1 evidences

Healthy adults adjusted intestinal zinc absorption when dietary zinc was low and diets were low in phytate; some zinc-status biomarkers did not change.

Trust comment: Controlled human feeding experiments using radiotracers (n=109) provide direct, reliable measures of zinc absorption.

Study Details

PMID:18469257
Participants:109
Impact:Inverse relationship (lower dietary zinc -> higher absorptive efficiency)
Trust score:4/5

erythrocyte osmotic fragility and zinc-transport protein expression

1 evidences

Healthy adults adjusted intestinal zinc absorption when dietary zinc was low and diets were low in phytate; some zinc-status biomarkers did not change.

Trust comment: Controlled human feeding experiments using radiotracers (n=109) provide direct, reliable measures of zinc absorption.

Study Details

PMID:18469257
Participants:109
Impact:No response to dietary zinc content (no change)
Trust score:4/5

fecal myeloperoxidase (MPO)

1 evidences

Daily preventive zinc, therapeutic zinc, or a high-zinc MNP did not change stool markers of intestinal inflammation (MPO, NEO, CAL) in young Laotian children.

Trust comment: Large, randomized, double-blind, placebo-controlled trial with pre-specified analyses on a 720-child EED subsample; high-quality design.

Study Details

PMID:32618258
Participants:720
Impact:No significant difference across groups at endline (P = 0.749)
Trust score:5/5

fecal neopterin (NEO)

1 evidences

Daily preventive zinc, therapeutic zinc, or a high-zinc MNP did not change stool markers of intestinal inflammation (MPO, NEO, CAL) in young Laotian children.

Trust comment: Large, randomized, double-blind, placebo-controlled trial with pre-specified analyses on a 720-child EED subsample; high-quality design.

Study Details

PMID:32618258
Participants:720
Impact:No significant difference across groups at endline (P = 0.226)
Trust score:5/5

fecal calprotectin (CAL)

1 evidences

Daily preventive zinc, therapeutic zinc, or a high-zinc MNP did not change stool markers of intestinal inflammation (MPO, NEO, CAL) in young Laotian children.

Trust comment: Large, randomized, double-blind, placebo-controlled trial with pre-specified analyses on a 720-child EED subsample; high-quality design.

Study Details

PMID:32618258
Participants:720
Impact:No significant difference across groups at endline (P = 0.229)
Trust score:5/5

plasma citrulline

1 evidences

Preventive or therapeutic zinc, or MNP, did not change plasma citrulline, kynurenine, tryptophan, or the KT ratio in young Laotian children.

Trust comment: Randomized controlled trial subsample (n=359) with robust biochemical assays; subsample and marginal categorical findings limit conclusions.

Study Details

PMID:31889508
Participants:359
Impact:No significant difference between intervention groups at endline
Trust score:4/5

kynurenine (plasma)

1 evidences

Preventive or therapeutic zinc, or MNP, did not change plasma citrulline, kynurenine, tryptophan, or the KT ratio in young Laotian children.

Trust comment: Randomized controlled trial subsample (n=359) with robust biochemical assays; subsample and marginal categorical findings limit conclusions.

Study Details

PMID:31889508
Participants:359
Impact:No overall endline difference; therapeutic zinc group had higher proportion in highest tertile (P = 0.035)
Trust score:4/5

tryptophan and KT ratio

1 evidences

Preventive or therapeutic zinc, or MNP, did not change plasma citrulline, kynurenine, tryptophan, or the KT ratio in young Laotian children.

Trust comment: Randomized controlled trial subsample (n=359) with robust biochemical assays; subsample and marginal categorical findings limit conclusions.

Study Details

PMID:31889508
Participants:359
Impact:No overall endline difference; marginally fewer low-tryptophan cases in therapeutic zinc group (P = 0.079)
Trust score:4/5

plasma copper

2 evidences

Perioperative zinc plus vitamin E transiently lowered plasma copper on postoperative day 3 and increased leukocyte MT2A expression at days 3 and 21, with no lasting copper depletion.

Trust comment: Randomized add-on trial in surgical patients with clear biomarker endpoints; moderate sample size and relevant measurements support credibility.

Study Details

PMID:38865064
Participants:78
Impact:significantly decreased on postoperative day 3 in zinc-vitE group; no difference by day 21
Trust score:4/5

Adolescent athletes taking 22 mg/day zinc for 12 weeks showed improved antioxidant markers but decreased plasma iron and copper.

Trust comment: Placebo-controlled trial in adolescents with clear biochemical outcomes but small sample and potential nutritional interactions.

Study Details

PMID:19277992
Participants:47
Impact:decreased in Zn-supplemented group (p = 0.015)
Trust score:4/5

serum insulin

3 evidences

Six weeks of magnesium-zinc-calcium-vitamin D co-supplementation in gestational diabetes improved fasting glucose, insulin-related markers and some lipid markers versus placebo.

Trust comment: Randomized double-blind trial with clear metabolic endpoints, but zinc was given as part of a multi-nutrient supplement so individual zinc effects are not isolated.

Study Details

PMID:29316405
Participants:60
Impact:-21.0 ±4.8 pmol/L vs +7.2 ±4.8 pmol/L (P<0.001)
Trust score:4/5

Six weeks of zinc plus vitamin E in women with gestational diabetes improved insulin levels, insulin resistance measures, some lipid measures, and upregulated PPAR-γ and LDLR expression.

Trust comment: Randomized, double-blind, placebo-controlled trial (n=54) showing consistent metabolic and gene-expression changes, though sample size is modest.

Study Details

PMID:29804469
Participants:54
Impact:Decreased (β = -3.81 vs placebo; p = 0.001)
Trust score:4/5

In pregnant women at risk for IUGR, 30 mg/day zinc for 10 weeks reduced inflammation and oxidative stress markers and lowered insulin; no effect on uterine artery PI.

Trust comment: Randomized double-blind placebo-controlled trial with biomarker endpoints but small sample (n=52) limits generalizability.

Study Details

PMID:31248307
Participants:52
Impact:-1.33 µIU/mL (β)
Trust score:4/5

HOMA-IR

1 evidences

Six weeks of zinc plus vitamin E in women with gestational diabetes improved insulin levels, insulin resistance measures, some lipid measures, and upregulated PPAR-γ and LDLR expression.

Trust comment: Randomized, double-blind, placebo-controlled trial (n=54) showing consistent metabolic and gene-expression changes, though sample size is modest.

Study Details

PMID:29804469
Participants:54
Impact:Decreased (β = -0.96 vs placebo; p = 0.002)
Trust score:4/5

Total and LDL cholesterol

2 evidences

6-month RCT of Lysulin (lysine, zinc, vitamin C) in pre-diabetes reduced progression to diabetes and improved glycaemic and lipid measures versus placebo.

Trust comment: Well-designed RCT with clinically meaningful endpoints, but formulation contains multiple active ingredients so effects cannot be attributed solely to zinc.

Study Details

PMID:32795739
Participants:110
Impact:decreased in Lysulin group (significant)
Trust score:3/5

Six weeks of zinc plus vitamin E in women with gestational diabetes improved insulin levels, insulin resistance measures, some lipid measures, and upregulated PPAR-γ and LDLR expression.

Trust comment: Randomized, double-blind, placebo-controlled trial (n=54) showing consistent metabolic and gene-expression changes, though sample size is modest.

Study Details

PMID:29804469
Participants:54
Impact:Total cholesterol -8.56 mg/dL (p = 0.03); LDL -8.72 mg/dL (p = 0.01) vs placebo
Trust score:4/5

serum zinc (SZn)

1 evidences

In ~4–7-month-old infants, zinc supplementation increased serum zinc and weight gain; combined iron+zinc improved iron status but appeared to reduce the zinc increase versus zinc alone.

Trust comment: Large randomized, double-masked trial (915 enrolled, 784 completed) with clear biochemical and growth endpoints; robust sample size.

Study Details

PMID:16306925
Participants:784
Impact:Increased +10.3 µmol/L in Zn-alone group; +8.0 µmol/L in Fe+Zn group (P = 0.03 for difference)
Trust score:4/5

hemoglobin and serum ferritin

1 evidences

In ~4–7-month-old infants, zinc supplementation increased serum zinc and weight gain; combined iron+zinc improved iron status but appeared to reduce the zinc increase versus zinc alone.

Trust comment: Large randomized, double-masked trial (915 enrolled, 784 completed) with clear biochemical and growth endpoints; robust sample size.

Study Details

PMID:16306925
Participants:784
Impact:Greater increases in Fe and Fe+Zn groups (Hb ≈ +22.6 and +20.6 g/L; SF ≈ +36.0 and +24.8 µg/L) vs Zn or placebo
Trust score:4/5

weight gain

10 evidences

Low birth weight infants given daily zinc had greater weight, length and head circumference gains by 6 months compared with placebo.

Trust comment: Randomized placebo-controlled trial with monthly anthropometry; moderate sample of completers but some attrition.

Study Details

PMID:21858548
Participants:76
Impact:greater weight at 6 mo: 4995 ± 74 g (zinc) vs 3896 ± 865 g (placebo) (P=0.036)
Trust score:4/5

Short-term zinc (with/without vitamin A) did not affect weight or length gains over 6 months in undernourished children.

Trust comment: Large randomized double-blind placebo-controlled trial with adequate follow-up showing null effect on growth.

Study Details

PMID:11756064
Participants:653
Impact:no significant change
Trust score:4/5

14 days of zinc supplementation raised plasma zinc but did not improve weight gain or speed recovery from diarrhea in hospitalized malnourished children.

Trust comment: Double-blind randomized placebo-controlled inpatient trial (n=87) with clear clinical and biochemical endpoints; biochemical but not clinical benefit observed.

Study Details

PMID:10103334
Participants:87
Impact:no significant change by day 14
Trust score:4/5

In ~4–7-month-old infants, zinc supplementation increased serum zinc and weight gain; combined iron+zinc improved iron status but appeared to reduce the zinc increase versus zinc alone.

Trust comment: Large randomized, double-masked trial (915 enrolled, 784 completed) with clear biochemical and growth endpoints; robust sample size.

Study Details

PMID:16306925
Participants:784
Impact:Higher in Zn-alone group (no magnitude reported)
Trust score:4/5

Adjunctive vitamin A plus zinc for 8 weeks did not change time to sputum smear or culture conversion or weight gain in adults with pulmonary TB.

Trust comment: Moderately sized randomized controlled trial with objective microbiological endpoints; null results reported clearly.

Study Details

PMID:21068353
Participants:154
Impact:No significant difference (≈2.3 kg vs 2.2 kg)
Trust score:4/5

In TB patients, zinc supplementation did not change culture conversion or weight gain; a multi-micronutrient supplement (not zinc) increased weight.

Trust comment: Large randomized double-blind placebo-controlled 2x2 trial (n=499) with clearly reported clinical outcomes.

Study Details

PMID:16135188
Participants:499
Impact:no effect (zinc); MMN +0.78 kg at 8 weeks
Trust score:5/5

Daily zinc improved growth, weight and reduced infections in supplemented stunted infants over 6 months.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear clinically important outcomes and significant p-values.

Study Details

PMID:10885352
Participants:100
Impact:+1.73 kg (zinc, stunted) vs +0.95 kg (placebo, stunted) over 6 months
Trust score:5/5

In growth-retarded preschool children, zinc (±calcium) supplementation increased annual height gain, vitamin A-containing regimens improved weight gain, and supplementation reduced days of illness.

Trust comment: Double-blind placebo-controlled trial with adequate sample size and clinically meaningful growth outcomes.

Study Details

PMID:12500659
Participants:156
Impact:+0.36–0.38 kg/year (greater in +ZnCaVA and +CaVA vs control)
Trust score:4/5

Infants born small for gestational age who received daily zinc showed greater weight and length gains over the first 6 months versus placebo.

Trust comment: Small double-blind randomized trial with clear anthropometric outcomes and significant effects on growth in this specific population.

Study Details

PMID:7636643
Participants:68
Impact:greater weight increments in zinc group (significant at 2 months, p < 0.003)
Trust score:4/5

Daily 5 mg zinc for 6 months increased weight gain and boys' height and reduced stunting in children with low linear growth.

Trust comment: Community randomized controlled trial with measured anthropometric outcomes and reasonable follow-up, though subgroup effects noted.

Study Details

PMID:18956153
Participants:85
Impact:increased in boys (P = 0.04) and girls (P = 0.05)
Trust score:4/5

ponderal growth

1 evidences

In Thai infants, zinc supplements raised blood zinc but did not improve growth; combined iron+zinc altered iron markers versus single supplements.

Trust comment: Large randomized placebo-controlled factorial trial (n=609) with measured biochemical endpoints supports high trustworthiness.

Study Details

PMID:16920862
Participants:609
Impact:no change (zinc had no significant effect)
Trust score:5/5

iron status (with combined supplementation)

1 evidences

In Thai infants, zinc supplements raised blood zinc but did not improve growth; combined iron+zinc altered iron markers versus single supplements.

Trust comment: Large randomized placebo-controlled factorial trial (n=609) with measured biochemical endpoints supports high trustworthiness.

Study Details

PMID:16920862
Participants:609
Impact:reduced response when zinc given with iron (iron alone increased Hb/ferritin more than iron+zinc)
Trust score:5/5

metabolic syndrome components (glucose, TG, HDL, BP, waist)

1 evidences

Combined zinc, magnesium and chromium supplementation did not change metabolic syndrome components but lowered serum C-reactive protein.

Trust comment: Small randomized double-blind trial (n=32) using a combined-mineral intervention; limited size and confounding between minerals lower specificity to zinc.

Study Details

PMID:29773176
Participants:32
Impact:no change after 24 weeks
Trust score:3/5

C-reactive protein (CRP)

4 evidences

Randomized placebo-controlled trial in hemodialysis patients; zinc raised serum zinc and produced a non-significant fall in CRP.

Trust comment: Randomized double-blind placebo-controlled trial but small sample (n=55), so moderate confidence.

Study Details

PMID:19541504
Participants:55
Impact:-3.0 mg/L (from 13.5 to 10.5 mg/L; not statistically significant)
Trust score:4/5

Combined zinc, magnesium and chromium supplementation did not change metabolic syndrome components but lowered serum C-reactive protein.

Trust comment: Small randomized double-blind trial (n=32) using a combined-mineral intervention; limited size and confounding between minerals lower specificity to zinc.

Study Details

PMID:29773176
Participants:32
Impact:decreased in the mineral-supplemented group (statistically significant; magnitude not reported)
Trust score:3/5

In women with T2DM and CHD, 12-week combined magnesium and zinc supplementation modestly improved fasting glucose, insulin, HDL, inflammatory marker CRP, antioxidant markers, and depression/anxiety scores versus placebo.

Trust comment: Randomized, double-blind, placebo-controlled trial with objective biochemical endpoints but modest sample size.

Study Details

PMID:32466773
Participants:55
Impact:Between-group β −0.85 mg/L (95% CI −1.26, −0.45); P < 0.001
Trust score:4/5

In preterm neonates with late-onset sepsis, 10 days of oral zinc plus antibiotics improved clinical sepsis scores and reduced CRP and procalcitonin versus placebo plus antibiotics.

Trust comment: Prospective randomized clinical trial with clear clinical and laboratory endpoints and a reasonable sample size.

Study Details

PMID:33285602
Participants:180
Impact:5.3±1.8 vs 6.1±2.0 mg/L after 10 days (p=0.008); ~0.8 mg/L lower
Trust score:4/5

stool output

2 evidences

Children with cholera given 30 mg/day zinc recovered faster and had shorter diarrhoea and lower stool output than placebo.

Trust comment: Double-blind, randomized, placebo-controlled trial with clinically meaningful, statistically significant effects on diarrhoea outcomes.

Study Details

PMID:18184631
Participants:164
Impact:1.6 kg/day (zinc) vs 1.8 kg/day (placebo); −11% (p=0.039)
Trust score:5/5

In undernourished young children with persistent diarrhea, zinc reduced stool output, prevented weight loss and sped recovery.

Trust comment: Double-blind randomized controlled trial with clearly reported group sizes (24 per arm) and statistically significant clinical outcomes.

Study Details

PMID:11332926
Participants:96
Impact:−39% cumulative 7‑day stool weight vs control (p<0.001)
Trust score:4/5

body weight (7 days)

1 evidences

In undernourished young children with persistent diarrhea, zinc reduced stool output, prevented weight loss and sped recovery.

Trust comment: Double-blind randomized controlled trial with clearly reported group sizes (24 per arm) and statistically significant clinical outcomes.

Study Details

PMID:11332926
Participants:96
Impact:+111 g (zinc group) vs −90 g (control) over 7 days
Trust score:4/5

clinical recovery rate (7 days)

1 evidences

In undernourished young children with persistent diarrhea, zinc reduced stool output, prevented weight loss and sped recovery.

Trust comment: Double-blind randomized controlled trial with clearly reported group sizes (24 per arm) and statistically significant clinical outcomes.

Study Details

PMID:11332926
Participants:96
Impact:+42 percentage points (88% vs 46% control)
Trust score:4/5

influenza antibody titre

1 evidences

In elderly subjects, oral zinc (or zinc+arginine) restored plasma zinc levels but did not enhance influenza antibody responses or lymphocyte counts.

Trust comment: Large randomized controlled design in elderly participants with biologic and immunologic endpoints; clear negative clinical immunogenicity result.

Study Details

PMID:10408666
Participants:384
Impact:no change versus vaccine-only control
Trust score:4/5

lymphocyte counts (CD3/CD4/CD8)

1 evidences

In elderly subjects, oral zinc (or zinc+arginine) restored plasma zinc levels but did not enhance influenza antibody responses or lymphocyte counts.

Trust comment: Large randomized controlled design in elderly participants with biologic and immunologic endpoints; clear negative clinical immunogenicity result.

Study Details

PMID:10408666
Participants:384
Impact:no change
Trust score:4/5

hemoglobin (Fe vs Fe+Zn)

1 evidences

In Indonesian infants, zinc supplements raised serum zinc, but combined iron+zinc was less effective at improving iron status than iron alone.

Trust comment: Large community-based randomized trial with substantial completed-sample biochemical data (n=549) and clear interaction findings.

Study Details

PMID:12663287
Participants:549
Impact:Hb higher in Fe alone vs Fe+Zn (119.4 vs 115.3 g/L; P<0.05)
Trust score:5/5

serum ferritin (Fe vs Fe+Zn)

1 evidences

In Indonesian infants, zinc supplements raised serum zinc, but combined iron+zinc was less effective at improving iron status than iron alone.

Trust comment: Large community-based randomized trial with substantial completed-sample biochemical data (n=549) and clear interaction findings.

Study Details

PMID:12663287
Participants:549
Impact:ferritin higher in Fe alone vs Fe+Zn (46.5 vs 32.3 μg/L; P<0.05)
Trust score:5/5

CD4 count (low-zinc patients)

1 evidences

In a small pilot study of HIV patients with poor CD4 recovery, zinc supplementation raised plasma zinc and was associated with CD4 increases in those initially zinc-deficient.

Trust comment: Small pilot randomized component with very limited sample size (total n=31) and subgroup randomization; findings are preliminary.

Study Details

PMID:24270132
Participants:31
Impact:increased from 176 to 250 cells/mm3 (≈+74 cells/mm3; P=0.042)
Trust score:3/5

gingival inflammation (GI)

1 evidences

In young adults with plaque-induced gingivitis, adjunctive zinc-containing intraoral stents reduced gingival inflammation (GI) more than control over 8 weeks.

Trust comment: Randomized double-blind placebo-controlled trial with objective clinical indices but small sample (41 completers) and short follow-up (8 weeks).

Study Details

PMID:41001958
Participants:41
Impact:reduced (mean at 8 weeks 1.61 vs 1.77 control; group differences P<0.001)
Trust score:4/5

bleeding on probing (BOP)

1 evidences

In young adults with plaque-induced gingivitis, adjunctive zinc-containing intraoral stents reduced gingival inflammation (GI) more than control over 8 weeks.

Trust comment: Randomized double-blind placebo-controlled trial with objective clinical indices but small sample (41 completers) and short follow-up (8 weeks).

Study Details

PMID:41001958
Participants:41
Impact:no significant intergroup difference
Trust score:4/5

mild adverse events

1 evidences

Randomized safety trial in older adults found zinc lozenges well tolerated with only mild adverse events and no serious clinical safety signals.

Trust comment: Randomized double-blind placebo-controlled trial in elderly with 66 completers; small sample but appropriate safety assessments and no serious events.

Study Details

PMID:16280656
Participants:66
Impact:4 participants (zinc) vs 3 (placebo) reported mild events; 0 serious adverse events
Trust score:4/5

overall safety/tolerability

1 evidences

Randomized safety trial in older adults found zinc lozenges well tolerated with only mild adverse events and no serious clinical safety signals.

Trust comment: Randomized double-blind placebo-controlled trial in elderly with 66 completers; small sample but appropriate safety assessments and no serious events.

Study Details

PMID:16280656
Participants:66
Impact:no clinically significant differences between zinc and placebo on exams, labs, or vitals
Trust score:4/5

amount of zinc absorbed

1 evidences

Crossover feeding study in women showed lower zinc absorption and a small drop in plasma zinc on a lactoovovegetarian diet compared with an omnivorous diet.

Trust comment: Controlled crossover feeding study with direct isotopic absorption measures in 21 women; small sample but strong design for absorption outcomes.

Study Details

PMID:9497185
Participants:21
Impact:35% lower (2.4 mg/d vs 3.7 mg/d)
Trust score:4/5

osmotic fragility

1 evidences

In zinc-deficient hemodialysis patients, three months of zinc supplementation increased serum zinc, improved red blood cell osmotic fragility and reduced lipid peroxidation (MDA), but some side effects occurred with zinc.

Trust comment: Randomized study in a specific clinical population (n=34) showing biochemical and functional RBC improvements, but small size and noted side effects reduce generalizability.

Study Details

PMID:11979503
Participants:34
Impact:improved (decreased) with zinc supplementation
Trust score:3/5

lipid peroxidation (MDA)

2 evidences

Zinc (100 mg/day) for 2 months increased blood zinc and antioxidant markers and reduced lipid peroxidation in hemodialysis patients.

Trust comment: Double-blind randomized crossover RCT in 65 HD patients with clear biochemical endpoints and significant p-values.

Study Details

PMID:23140661
Participants:65
Impact:↓ significant decrease (P = .003 to P < .001)
Trust score:4/5

In zinc-deficient hemodialysis patients, three months of zinc supplementation increased serum zinc, improved red blood cell osmotic fragility and reduced lipid peroxidation (MDA), but some side effects occurred with zinc.

Trust comment: Randomized study in a specific clinical population (n=34) showing biochemical and functional RBC improvements, but small size and noted side effects reduce generalizability.

Study Details

PMID:11979503
Participants:34
Impact:decreased with zinc supplementation
Trust score:3/5

adverse effects

2 evidences

In zinc-deficient hemodialysis patients, three months of zinc supplementation increased serum zinc, improved red blood cell osmotic fragility and reduced lipid peroxidation (MDA), but some side effects occurred with zinc.

Trust comment: Randomized study in a specific clinical population (n=34) showing biochemical and functional RBC improvements, but small size and noted side effects reduce generalizability.

Study Details

PMID:11979503
Participants:34
Impact:nausea, vomiting, fever, muscle pain, weakness reported during zinc treatment
Trust score:3/5

Preoperative 40 mg zinc gargle had no consistent benefit over magnesium or budesonide; incidence and severity of postoperative sore throat were comparable across groups.

Trust comment: Well-conducted, double-blind randomized trial with adequate sample (n=180), but found no clear clinically significant benefit of zinc gargle.

Study Details

PMID:38693477
Participants:180
Impact:no adverse effects reported
Trust score:4/5

Pain (VAS)

1 evidences

In a small three-arm RCT (topical steroid +/- systemic zinc or vitamin D) over 8 weeks, adjunctive vitamin D produced earlier pain reduction versus steroid alone (by week 3) though zinc showed the largest clinical benefit; vitamin D adjunct effects were modest overall.

Trust comment: Randomized three-arm clinical trial with complete follow-up (n=42) and validated clinical/pain measures, though moderate sample size and lack of biochemical zinc levels are limitations.

Study Details

PMID:40457259
Participants:42
Impact:by Week 3 median VAS 3 in TA+Zn vs 5 in TA only (p=0.015); greater and more sustained reduction through Week 8
Trust score:4/5

clinical severity (Thongprasom score)

1 evidences

In a small three-arm RCT (topical steroid +/- systemic zinc or vitamin D) over 8 weeks, adjunctive vitamin D produced earlier pain reduction versus steroid alone (by week 3) though zinc showed the largest clinical benefit; vitamin D adjunct effects were modest overall.

Trust comment: Randomized three-arm clinical trial with complete follow-up (n=42) and validated clinical/pain measures, though moderate sample size and lack of biochemical zinc levels are limitations.

Study Details

PMID:40457259
Participants:42
Impact:median score at Week 8: 0 (TA+Zn) vs 1.5 (TA); greatest improvement in zinc group
Trust score:4/5

serum leptin (women)

1 evidences

Double-blind randomized trial in hemodialysis patients showed that 60 days of zinc (100 mg/day elemental) raised serum zinc and lowered serum leptin in women.

Trust comment: Randomized double-blind placebo-controlled trial (n=60) with clear biochemical endpoints; moderate size and limited duration (60 days).

Study Details

PMID:24188897
Participants:60
Impact:significant decrease after supplementation
Trust score:4/5

association zinc vs leptin

1 evidences

Double-blind randomized trial in hemodialysis patients showed that 60 days of zinc (100 mg/day elemental) raised serum zinc and lowered serum leptin in women.

Trust comment: Randomized double-blind placebo-controlled trial (n=60) with clear biochemical endpoints; moderate size and limited duration (60 days).

Study Details

PMID:24188897
Participants:60
Impact:negative association (β = -0.33, P = 0.03) after adjustment
Trust score:4/5

hair cortisol concentration (HCC)

1 evidences

Large randomized trial sub-study found that different zinc supplementation strategies did not meaningfully change hair cortisol (a chronic stress marker) in young Laotian children.

Trust comment: Large randomized controlled trial subgroup (n=512) with rigorous methods; convenience sampling for hair sub-study and potential biomarker sensitivity issues caution interpretation.

Study Details

PMID:30591656
Participants:512
Impact:no significant difference across intervention groups at endline; marginally smaller reduction in therapeutic zinc vs preventive zinc but not clinically meaningful
Trust score:4/5

body mass (BMI and related anthropometrics)

1 evidences

In children with chronic kidney disease, daily zinc (15 vs 30 mg) for up to 12 months led to a small but significant increase in body mass and some anthropometric measures, especially with 30 mg/day; serum zinc, albumin and CRP showed no consistent improvement.

Trust comment: Randomized multicenter trial in humans with objective anthropometric and biochemical measures, but small sample, partial masking, no placebo control group, and 27% attrition reduces certainty.

Study Details

PMID:31694220
Participants:35
Impact:+small but significant increase (greater effect with 30 mg/day)
Trust score:3/5

inflammation (CRP)

1 evidences

In children with chronic kidney disease, daily zinc (15 vs 30 mg) for up to 12 months led to a small but significant increase in body mass and some anthropometric measures, especially with 30 mg/day; serum zinc, albumin and CRP showed no consistent improvement.

Trust comment: Randomized multicenter trial in humans with objective anthropometric and biochemical measures, but small sample, partial masking, no placebo control group, and 27% attrition reduces certainty.

Study Details

PMID:31694220
Participants:35
Impact:no consistent or significant decrease overall
Trust score:3/5

serum zinc status (low pZn)

1 evidences

A fortified seasoning powder served with school lunch reduced the prevalence of urinary iodine deficiency and improved zinc status in children; no clear effect on anemia prevalence.

Trust comment: Large randomized controlled trial with objective biochemical outcomes and monitored adherence; effect estimates reported, though single setting and mixed outcomes.

Study Details

PMID:16702330
Participants:569
Impact:reduced odds of zinc deficiency (OR 0.63; ~−37% odds)
Trust score:4/5

urinary iodine deficiency

1 evidences

A fortified seasoning powder served with school lunch reduced the prevalence of urinary iodine deficiency and improved zinc status in children; no clear effect on anemia prevalence.

Trust comment: Large randomized controlled trial with objective biochemical outcomes and monitored adherence; effect estimates reported, though single setting and mixed outcomes.

Study Details

PMID:16702330
Participants:569
Impact:reduced odds (OR 0.52; ~−48% odds)
Trust score:4/5

anemia (hemoglobin)

2 evidences

Provision of small-quantity lipid-based nutrient supplements plus illness treatment and feeding advice increased growth and lowered stunting/wasting prevalence versus non-intervention, but varying the zinc content of the supplements (0, 5, 10 mg or tablet) produced no clear zinc-dose dependent effects on plasma zinc or growth.

Trust comment: Large, well-conducted cluster-randomized trial with rigorous procedures and objective outcomes; some adherence and masking limitations but overall high-quality evidence.

Study Details

PMID:25816354
Participants:3220
Impact:reduced anemia prevalence in intervention vs non-intervention (~91.1% to 79.1%; ≈−12 percentage points)
Trust score:5/5

A fortified seasoning powder served with school lunch reduced the prevalence of urinary iodine deficiency and improved zinc status in children; no clear effect on anemia prevalence.

Trust comment: Large randomized controlled trial with objective biochemical outcomes and monitored adherence; effect estimates reported, though single setting and mixed outcomes.

Study Details

PMID:16702330
Participants:569
Impact:no significant effect (OR 1.02)
Trust score:4/5

stunting prevalence

2 evidences

In pooled infant trials, blanket zinc supplementation did not prevent overall growth faltering, but zinc reduced odds of stunting and improved length growth in anemic subgroups.

Trust comment: Large pooled randomized, placebo-controlled multicountry trials with pre-planned analyses and subgroup findings, though effects were subgroup-specific.

Study Details

PMID:18806109
Participants:2451
Impact:reduced odds of stunting: OR 0.80 (95% CI 0.64–1.0)
Trust score:5/5

Provision of small-quantity lipid-based nutrient supplements plus illness treatment and feeding advice increased growth and lowered stunting/wasting prevalence versus non-intervention, but varying the zinc content of the supplements (0, 5, 10 mg or tablet) produced no clear zinc-dose dependent effects on plasma zinc or growth.

Trust comment: Large, well-conducted cluster-randomized trial with rigorous procedures and objective outcomes; some adherence and masking limitations but overall high-quality evidence.

Study Details

PMID:25816354
Participants:3220
Impact:reduced in intervention cohort vs non-intervention (~39.3% to 29.3%; ≈−10 percentage points)
Trust score:5/5

plasma zinc concentration (pZn)

1 evidences

Provision of small-quantity lipid-based nutrient supplements plus illness treatment and feeding advice increased growth and lowered stunting/wasting prevalence versus non-intervention, but varying the zinc content of the supplements (0, 5, 10 mg or tablet) produced no clear zinc-dose dependent effects on plasma zinc or growth.

Trust comment: Large, well-conducted cluster-randomized trial with rigorous procedures and objective outcomes; some adherence and masking limitations but overall high-quality evidence.

Study Details

PMID:25816354
Participants:3220
Impact:no consistent increase attributable to different zinc doses (no difference among zinc groups)
Trust score:5/5

all-cause mortality

5 evidences

Daily zinc from 6 weeks of age reduced physician-diagnosed diarrhea, dysentery and acute upper respiratory infections in Tanzanian infants; multivitamins had no benefit.

Trust comment: Large, double-blind randomized controlled trial with clear clinical endpoints, supporting high internal validity.

Study Details

PMID:26203094
Participants:2360
Impact:nonsignificant increase (HR 1.80; 95% CI 0.98–3.31; P=0.06)
Trust score:5/5

Zinc supplementation had no effect on falciparum malaria incidence but reduced diarrhoea prevalence; mortality was lower numerically but not statistically significant.

Trust comment: Well-conducted randomized, double-blind placebo trial with high completion rate; reported clear primary and secondary outcomes.

Study Details

PMID:11431296
Participants:685
Impact:numerically lower (5 vs 12; p=0.1; not significant)
Trust score:4/5

Daily zinc supplementation in young children did not significantly reduce overall mortality in this large community trial in Pemba, Zanzibar.

Trust comment: Large, randomized, double-blind placebo-controlled trial with intention-to-treat analysis, though the primary effect was not statistically significant.

Study Details

PMID:17368154
Participants:42546
Impact:-7% (non-significant; 95% CI -6% to 19%, p=0.29)
Trust score:4/5

In a very large double-blind cluster-randomized trial, adding 10 mg zinc daily to iron+folic acid did not change all-cause mortality or hospitalization rates in young children over 12 months.

Trust comment: Very large, double-blind cluster-randomized trial with systematic surveillance of deaths and hospitalizations; high precision and generalizability for these outcomes.

Study Details

PMID:17182810
Participants:94359
Impact:no significant effect (hazard ratio ≈1.02)
Trust score:5/5

Weekly oral zinc reduced pneumonia episodes and slightly reduced diarrhea incidence and reduced deaths in young children in this urban Bangladesh trial.

Trust comment: Large randomized trial with meaningful clinical endpoints and mortality benefit, though notable withdrawals may affect generalizability.

Study Details

PMID:16168782
Participants:1621
Impact:deaths 2 vs 14 (significant reduction; p=0.013)
Trust score:4/5

hospitalizations (all-cause and cause-specific)

1 evidences

In a very large double-blind cluster-randomized trial, adding 10 mg zinc daily to iron+folic acid did not change all-cause mortality or hospitalization rates in young children over 12 months.

Trust comment: Very large, double-blind cluster-randomized trial with systematic surveillance of deaths and hospitalizations; high precision and generalizability for these outcomes.

Study Details

PMID:17182810
Participants:94359
Impact:no significant effect on overall, diarrhea-specific or pneumonia-specific hospitalization rates
Trust score:5/5

S. mansoni reinfection rate

1 evidences

In schoolchildren given zinc (30 or 50 mg on schooldays) vs placebo for 12 months, reinfection rates with S. mansoni did not differ, but the median intensity of S. mansoni reinfection (eggs/g feces) was significantly lower in the zinc group.

Trust comment: Randomized, double-blind, placebo-controlled trial in humans with objective parasitologic outcomes; moderate sample and external factors (food program) may have influenced results.

Study Details

PMID:9023465
Participants:313
Impact:no significant difference (25% vs 29%)
Trust score:4/5

S. mansoni reinfection intensity

1 evidences

In schoolchildren given zinc (30 or 50 mg on schooldays) vs placebo for 12 months, reinfection rates with S. mansoni did not differ, but the median intensity of S. mansoni reinfection (eggs/g feces) was significantly lower in the zinc group.

Trust comment: Randomized, double-blind, placebo-controlled trial in humans with objective parasitologic outcomes; moderate sample and external factors (food program) may have influenced results.

Study Details

PMID:9023465
Participants:313
Impact:reduced median intensity (7 vs 13 eggs/g feces; statistically significant)
Trust score:4/5

CD4 count recovery (immune recovery)

1 evidences

Among HIV patients with immunovirological discordance randomized to zinc 15 mg/day vs placebo for 12 months, zinc supplementation did not produce a greater CD4 recovery compared with placebo; baseline hypozincemia was common in discordant patients.

Trust comment: Randomized double-blind study but small sample size and limited power to detect immunologic effects; objective lab measures but limited generalizability.

Study Details

PMID:33481813
Participants:40
Impact:no significant difference in CD4 increase between zinc and placebo groups
Trust score:3/5

plasma zinc level (hypozincemia correction)

1 evidences

Among HIV patients with immunovirological discordance randomized to zinc 15 mg/day vs placebo for 12 months, zinc supplementation did not produce a greater CD4 recovery compared with placebo; baseline hypozincemia was common in discordant patients.

Trust comment: Randomized double-blind study but small sample size and limited power to detect immunologic effects; objective lab measures but limited generalizability.

Study Details

PMID:33481813
Participants:40
Impact:supplemented hypozincemic patients achieved higher zinc levels but no clear immune benefit (no significant CD4 effect)
Trust score:3/5

asthma clinical symptoms (cough, wheeze, dyspnea)

1 evidences

In asthmatic children given zinc 50 mg/day for 8 weeks, blood zinc rose and clinical symptoms and lung function improved versus placebo.

Trust comment: Randomized double-blind placebo-controlled trial with objective spirometry and clear biochemical change, moderate sample size.

Study Details

PMID:24960516
Participants:284
Impact:significant improvement (reported vs placebo)
Trust score:4/5

spirometry (FVC, FEV1, FEV1/FVC)

1 evidences

In asthmatic children given zinc 50 mg/day for 8 weeks, blood zinc rose and clinical symptoms and lung function improved versus placebo.

Trust comment: Randomized double-blind placebo-controlled trial with objective spirometry and clear biochemical change, moderate sample size.

Study Details

PMID:24960516
Participants:284
Impact:significant improvement (reported vs placebo)
Trust score:4/5

Mortality

7 evidences

Weekly zinc (with or without retinol) added to TB therapy did not improve sputum conversion, radiographic, clinical outcomes, or mortality compared with placebo.

Trust comment: Well-designed randomized, double-blind placebo-controlled trial in 350 patients, though mortality imbalance warrants cautious interpretation.

Study Details

PMID:20958890
Participants:350
Impact:no significant difference (zinc deaths 9 vs placebo 2; HR 1.71, 95% CI 0.88–3.58)
Trust score:4/5

Zinc given to children with severe malnutrition led to biochemical zinc recovery, higher albumin and improved blood parameters, and fewer deaths compared with controls.

Trust comment: Large randomized double-blind controlled trial in 300 children with objective biochemical and clinical endpoints, though exact effect sizes for some outcomes are not reported.

Study Details

PMID:14725412
Participants:300
Impact:reduced (very few deaths in supplemented group vs more deaths in control)
Trust score:4/5

In infants with probable serious bacterial infection, adding 10 mg zinc daily to antibiotics reduced treatment failure compared with placebo.

Trust comment: Large randomized double-blind placebo-controlled multicenter trial with clinically important primary outcome and intention-to-treat analysis.

Study Details

PMID:22656335
Participants:700
Impact:10 deaths (zinc) vs 17 deaths (placebo); RR 0.57 (not statistically significant, p=0.15)
Trust score:5/5

Zinc supplementation (10 mg) in children with PEM reduced in-hospital mortality and several morbidity outcomes and improved short-term weight status post-discharge.

Trust comment: Large randomized, double-blind clinical trial in a high-risk population with clinically meaningful outcome reductions reported.

Study Details

PMID:14725411
Participants:300
Impact:Reduced (from 16.7% in controls to 4.7% with zinc)
Trust score:4/5

In very-low-birth-weight preterm neonates, oral zinc supplementation reduced morbidity and mortality versus placebo, with similar weight gain.

Trust comment: Double-blind randomized controlled trial with clinically meaningful endpoints and statistically significant results.

Study Details

PMID:24025633
Participants:193
Impact:higher in placebo control (RR 2.37; 95% CI 1.08–5.18; P = 0.006)
Trust score:5/5

In severely malnourished young children, higher-dose zinc did not improve growth and was linked to higher death rates.

Trust comment: Randomized double-blind trial in humans with clear mortality signal but relatively small sample and specific severe-malnutrition setting.

Study Details

PMID:9734756
Participants:141
Impact:↑353% (RR 4.53; 95% CI 1.09–18.8) with high-dose zinc vs low-dose
Trust score:4/5

Neonates with probable sepsis given zinc plus standard care had no significant change in mortality, hospital stay, or need for higher-line antibiotics.

Trust comment: Well-powered double-blind RCT with clear negative findings and balanced baseline characteristics.

Study Details

PMID:23255688
Participants:614
Impact:no significant difference (9.77% zinc vs 7.81% placebo; p=0.393)
Trust score:4/5

zinc treatment uptake for diarrhea

1 evidences

Providing zinc at home massively increased zinc treatment of diarrhea but did not reduce community diarrhea incidence; household-reported ALRI episodes were reduced.

Trust comment: Large village-randomized trial with robust surveillance and objective clinic data, but possible delivery/ascertainment biases and some baseline differences between clusters.

Study Details

PMID:24835009
Participants:3024
Impact:61.2% (home zinc) vs 5.4% (comparison); +55.8 percentage points (p<0.0001)
Trust score:4/5

diarrhea incidence (community-level)

1 evidences

Providing zinc at home massively increased zinc treatment of diarrhea but did not reduce community diarrhea incidence; household-reported ALRI episodes were reduced.

Trust comment: Large village-randomized trial with robust surveillance and objective clinic data, but possible delivery/ascertainment biases and some baseline differences between clusters.

Study Details

PMID:24835009
Participants:3024
Impact:no significant change (no community-level decrease detected)
Trust score:4/5

reported ALRI incidence (household surveillance)

1 evidences

Providing zinc at home massively increased zinc treatment of diarrhea but did not reduce community diarrhea incidence; household-reported ALRI episodes were reduced.

Trust comment: Large village-randomized trial with robust surveillance and objective clinic data, but possible delivery/ascertainment biases and some baseline differences between clusters.

Study Details

PMID:24835009
Participants:3024
Impact:32% fewer ALRI episodes in zinc villages (adjusted RR 0.68, 95% CI 0.46–0.99)
Trust score:4/5

plasma phospholipid nervonic acid composition

1 evidences

Daily consumption of mildly Zn-fortified water for 20 weeks modestly increased plasma phospholipid nervonic acid, especially in children who were Zn-deficient at baseline.

Trust comment: Double-blind randomized trial with biochemical endpoints and clear subgroup effect though modest sample size.

Study Details

PMID:29352828
Participants:186
Impact:B = +0.109 (95% CI 0.001–0.218) overall; in Zn-deficient children B = +0.230 (95% CI 0.023–0.488)
Trust score:4/5

change in plasma zinc concentration (PZC)

1 evidences

Short-term daily 5 mg zinc for 21 days markedly raised plasma zinc concentration in young children; impaired intestinal permeability attenuated but did not prevent the increase.

Trust comment: Randomized placebo-controlled trial with objective biomarker outcomes and reasonable sample size.

Study Details

PMID:23689263
Participants:282
Impact:mean increase +15.6 ± 13.3 µg/dL in zinc group vs +0.02 ± 10.9 µg/dL in placebo (P < 0.0001)
Trust score:4/5

effect modification by intestinal permeability (L:M ratio)

1 evidences

Short-term daily 5 mg zinc for 21 days markedly raised plasma zinc concentration in young children; impaired intestinal permeability attenuated but did not prevent the increase.

Trust comment: Randomized placebo-controlled trial with objective biomarker outcomes and reasonable sample size.

Study Details

PMID:23689263
Participants:282
Impact:higher urinary L:M associated with smaller PZC increase (–1.1 µg/dL per 50% increase in L:M; P=0.014)
Trust score:4/5

growth (weight, length/height, mid-arm circumference)

1 evidences

Daily zinc (12.5 mg) for 6 months raised serum zinc in a subsample but did not change growth measures (weight, height, arm circumference) compared with placebo.

Trust comment: Large double-blind randomized trial with high completion rate and objective anthropometric measures but null effects on growth outcomes.

Study Details

PMID:14681282
Participants:685
Impact:no significant differences between zinc and placebo during follow-up
Trust score:4/5

serum zinc concentration (subsample)

1 evidences

Daily zinc (12.5 mg) for 6 months raised serum zinc in a subsample but did not change growth measures (weight, height, arm circumference) compared with placebo.

Trust comment: Large double-blind randomized trial with high completion rate and objective anthropometric measures but null effects on growth outcomes.

Study Details

PMID:14681282
Participants:685
Impact:increased in zinc-supplemented children (reported increase; no full group growth effect)
Trust score:4/5

subjective tinnitus severity score

1 evidences

Oral zinc 50 mg daily for 2 months was associated with a large mean drop in subjective tinnitus severity score versus baseline in treated patients, but the trial was small and some clinical endpoints were not statistically different versus placebo.

Trust comment: Randomized placebo-controlled study but small and unbalanced groups with limited power and mixed statistical findings.

Study Details

PMID:12544035
Participants:41
Impact:mean score decreased from 5.25 to 2.82 in zinc group (mean change –2.43; reported p<0.001 versus baseline)
Trust score:3/5

clinically favorable progress (subjective)

1 evidences

Oral zinc 50 mg daily for 2 months was associated with a large mean drop in subjective tinnitus severity score versus baseline in treated patients, but the trial was small and some clinical endpoints were not statistically different versus placebo.

Trust comment: Randomized placebo-controlled study but small and unbalanced groups with limited power and mixed statistical findings.

Study Details

PMID:12544035
Participants:41
Impact:46.4% of zinc-treated patients showed clinically favorable progress (not statistically significant vs placebo)
Trust score:3/5

Symptom disappearance at day 5

1 evidences

Non-hospitalized adults with COVID-19/covid-like illness received melatonin, zinc and multivitamins (including vitamin D) or placebo; the supplement arm had faster symptom resolution by days 5 and 10.

Trust comment: Randomized double-blind RCT with moderate sample size, but zinc was given as part of a combination (melatonin + multivitamins), so effects cannot be attributed to zinc alone.

Study Details

PMID:37419768
Participants:163
Impact:+16.5 percentage points (49.4% vs 32.9%)
Trust score:3/5

Symptom disappearance at day 10

1 evidences

Non-hospitalized adults with COVID-19/covid-like illness received melatonin, zinc and multivitamins (including vitamin D) or placebo; the supplement arm had faster symptom resolution by days 5 and 10.

Trust comment: Randomized double-blind RCT with moderate sample size, but zinc was given as part of a combination (melatonin + multivitamins), so effects cannot be attributed to zinc alone.

Study Details

PMID:37419768
Participants:163
Impact:+13.4 percentage points (80.5% vs 67.1%)
Trust score:3/5

Hospitalization or ventilation requirement

1 evidences

Non-hospitalized adults with COVID-19/covid-like illness received melatonin, zinc and multivitamins (including vitamin D) or placebo; the supplement arm had faster symptom resolution by days 5 and 10.

Trust comment: Randomized double-blind RCT with moderate sample size, but zinc was given as part of a combination (melatonin + multivitamins), so effects cannot be attributed to zinc alone.

Study Details

PMID:37419768
Participants:163
Impact:0 events in both groups (no difference)
Trust score:3/5

Duration of severe pneumonia

1 evidences

In hospitalized children (2 months–5 years) with severe pneumonia, adjunctive oral zinc did not significantly shorten duration of severe pneumonia, pneumonia, or hospital stay compared with placebo.

Trust comment: Randomized double-blind placebo-controlled trial in hospitalized children with clearly reported outcomes, but excluded malnourished children and lacked baseline zinc measurements.

Study Details

PMID:22856593
Participants:117
Impact:Median +8.2 hours (34.2 h zinc vs 26.0 h placebo), non-significant (p=0.219)
Trust score:4/5

Duration of hospitalization

3 evidences

In children with rotavirus diarrhea, zinc alone or zinc plus Saccharomyces boulardii shortened diarrhea and hospital stay compared to rehydration alone.

Trust comment: Large randomized treatment-group study in children with clear clinical outcomes, though exact effect sizes not reported in text excerpt.

Study Details

PMID:21261786
Participants:480
Impact:decreased (statistically significant vs control in zinc and zinc+S. boulardii groups)
Trust score:4/5

In hospitalized children (2 months–5 years) with severe pneumonia, adjunctive oral zinc did not significantly shorten duration of severe pneumonia, pneumonia, or hospital stay compared with placebo.

Trust comment: Randomized double-blind placebo-controlled trial in hospitalized children with clearly reported outcomes, but excluded malnourished children and lacked baseline zinc measurements.

Study Details

PMID:22856593
Participants:117
Impact:Median +1.5 hours (73.5 h zinc vs 72.0 h placebo), non-significant (p≈0.193)
Trust score:4/5

In hospitalized young children with severe pneumonia, adjunct zinc did not shorten clinical signs or hospital stay overall and was linked to longer pneumonia duration in the hot season.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear null overall results but a season-specific adverse signal.

Study Details

PMID:16685051
Participants:299
Impact:no significant difference
Trust score:4/5

Dietary zinc intake density

1 evidences

In men adopting cholesterol-lowering, high-fiber diets, zinc intake density and plasma zinc levels were maintained over 12–24 months; no adverse effect on zinc status was observed.

Trust comment: Large, long-term study within a randomized dietary trial showing stable zinc status, though it is a secondary analysis and not a zinc-supplement intervention.

Study Details

PMID:7594123
Participants:365
Impact:No change from baseline (mg/1000 kcal unchanged)
Trust score:4/5

Fractional zinc absorption

5 evidences

Pregnant women taking iron-containing prenatal supplements had much lower fractional zinc absorption and lower plasma zinc than unsupplemented controls; adding zinc to prenatal supplements reduced this adverse effect.

Trust comment: Stable-isotope measurements in a defined cohort (n=47) with clear group comparisons; sample size modest.

Study Details

PMID:10958820
Participants:47
Impact:reduced to ~20.5% (Fe) and 20.2% (Fe+Zn) vs 47.0% in unsupplemented controls (~−27 pp)
Trust score:4/5

Reducing dietary phytate (corn-soy diet) increased zinc absorption in children recovering from tuberculosis but had no effect in well children.

Trust comment: Human stable-isotope study with objective absorption measures but very small short-term sample (n=23), limiting external validity.

Study Details

PMID:11110854
Participants:23
Impact:In TB-recovery children increased from 0.24 to 0.41 (absolute +0.17, P<0.05)
Trust score:3/5

Substituting biofortified maize increased children's zinc intake and total absorbed zinc compared with control maize, meeting requirements similarly to zinc-fortified maize.

Trust comment: Randomized feeding study with stable-isotope absorption measures in 60 children; outcomes directly relevant and statistically significant.

Study Details

PMID:25733467
Participants:60
Impact:no significant difference between control (0.28 ± 0.10) and biofortified maize (0.22 ± 0.06)
Trust score:4/5

Fortifying wheat with higher zinc increased total absorbed zinc while fractional absorption fell with higher fortification; values remained stable over ~7 weeks.

Trust comment: Controlled feeding and repeated measures with moderate sample size provide reliable absorption data.

Study Details

PMID:15755834
Participants:41
Impact:decreased with higher fortification (0.341 → 0.237 → 0.133 for Zn-0, Zn-3, Zn-9; P < 0.001)
Trust score:4/5

Ten-week feeding trial found no significant differences in fractional or total absorbed zinc between low-phytate and control maize groups.

Trust comment: Randomized feeding trial with objective isotope-based absorption measures but small group sizes limit power to detect modest effects.

Study Details

PMID:16400050
Participants:60
Impact:no significant difference between maize groups (0.32, 0.28, 0.29 respectively)
Trust score:3/5

Mental Development Index (MDI) at 13 months

1 evidences

In a subsample follow-up of infants whose mothers received prenatal zinc (30 mg/day) or placebo, infants of zinc-supplemented mothers had slightly lower mental and psychomotor development scores at 13 months compared with placebo.

Trust comment: Originally randomized prenatal trial but follow-up used a selected subsample with potential selection bias and limited control for confounders despite statistical adjustment.

Study Details

PMID:12147372
Participants:168
Impact:−3.3 points (placebo higher; regression coefficient=3.3, p=0.04)
Trust score:3/5

Psychomotor Development Index (PDI) at 13 months

1 evidences

In a subsample follow-up of infants whose mothers received prenatal zinc (30 mg/day) or placebo, infants of zinc-supplemented mothers had slightly lower mental and psychomotor development scores at 13 months compared with placebo.

Trust comment: Originally randomized prenatal trial but follow-up used a selected subsample with potential selection bias and limited control for confounders despite statistical adjustment.

Study Details

PMID:12147372
Participants:168
Impact:−5.1 points (placebo higher; regression coefficient=5.1, p=0.04)
Trust score:3/5

fasting serum glucose

1 evidences

Randomized placebo-controlled trial in type 2 diabetes patients found that 20 mg/day zinc for 60 days significantly lowered fasting serum glucose overall, with a larger response in older patients.

Trust comment: Randomized placebo-controlled trial reporting significant glucose-lowering with zinc, but effect sizes and completed-participant counts are not provided in the excerpt and full data are needed for quantitative interpretation.

Study Details

PMID:35345925
Participants:144
Impact:Significant decrease with zinc vs placebo (magnitude not provided in excerpt)
Trust score:3/5

HbA1c

3 evidences

Randomized placebo-controlled trial in type 2 diabetes patients found that 20 mg/day zinc for 60 days significantly lowered fasting serum glucose overall, with a larger response in older patients.

Trust comment: Randomized placebo-controlled trial reporting significant glucose-lowering with zinc, but effect sizes and completed-participant counts are not provided in the excerpt and full data are needed for quantitative interpretation.

Study Details

PMID:35345925
Participants:144
Impact:Measured pre/post; study reports improvement in glucose control, details not specified in excerpt
Trust score:3/5

6-month RCT of Lysulin (lysine, zinc, vitamin C) in pre-diabetes reduced progression to diabetes and improved glycaemic and lipid measures versus placebo.

Trust comment: Well-designed RCT with clinically meaningful endpoints, but formulation contains multiple active ingredients so effects cannot be attributed solely to zinc.

Study Details

PMID:32795739
Participants:110
Impact:significant reduction in Lysulin group (value not reported in excerpt)
Trust score:3/5

Type 2 diabetics had lower serum zinc than controls; 3 months of oral zinc supplementation raised serum zinc and reduced HbA1c% in supplemented patients.

Trust comment: Controlled supplementation trial but single-blind and limited reporting of effect sizes for some outcomes.

Study Details

PMID:16532095
Participants:101
Impact:decreased significantly after 3 months in supplemented group
Trust score:3/5

serum iron

2 evidences

Randomized trial in children with coeliac disease: adding four weeks of zinc to a gluten-free diet increased serum zinc and iron more than diet alone; copper change was not significantly different.

Trust comment: Randomized controlled trial in 71 children; direct human evidence but moderate sample size and short supplement duration.

Study Details

PMID:29141505
Participants:71
Impact:greater increase with GFD + zinc (significant)
Trust score:4/5

Randomized workplace nutrition intervention providing oral nutrition supplements (multi‑vitamin/mineral formula including minerals) plus education vs education alone in female workers; intervention improved biochemical micronutrient markers including serum zinc, iron, and total serum calcium and reduced micronutrient deficiency prevalence.

Trust comment: Large randomized trial with objective biochemical outcomes, but use of a multinutrient ONS means effects cannot be attributed to zinc alone.

Study Details

PMID:38684383
Participants:500
Impact:+1.4 μmol/L (from 13.9 to 15.3 μmol/L)
Trust score:4/5

serum copper

6 evidences

Randomized trial in non‑alcoholic cirrhosis showed 90 days of 50 mg zinc daily improved Child‑Pugh score and lowered copper and creatinine versus placebo.

Trust comment: Randomized, placebo‑controlled trial with clear biochemical outcomes but modest size and per‑protocol analysis limit generalizability.

Study Details

PMID:22827782
Participants:60
Impact:decreased (P = 0.01)
Trust score:3/5

Daily oral polaprezinc (34 mg Zn/day) in zinc-deficient hemodialysis patients increased serum zinc, lowered serum copper and ferritin, and reduced the erythropoietin responsiveness index (ERI), allowing lower ESA requirements.

Trust comment: Randomized multicenter trial in zinc-deficient HD patients with objective biochemical and clinical endpoints; open-label and modest size are limitations.

Study Details

PMID:25988769
Participants:66
Impact:Decreased from 89±17 to 79±12 µg/dL in polaprezinc group; control unchanged
Trust score:4/5

Three months of curcumin increased serum zinc and the zinc/copper ratio and lowered serum copper in adults with β-thalassemia intermedia.

Trust comment: Small (n=30) randomized double-blind trial measuring mineral biomarkers; limited sample size reduces generalizability.

Study Details

PMID:33432439
Participants:30
Impact:decrease (significant)
Trust score:3/5

Randomized trial in children with coeliac disease: adding four weeks of zinc to a gluten-free diet increased serum zinc and iron more than diet alone; copper change was not significantly different.

Trust comment: Randomized controlled trial in 71 children; direct human evidence but moderate sample size and short supplement duration.

Study Details

PMID:29141505
Participants:71
Impact:no significant difference between groups
Trust score:4/5

Daily iron supplementation in pregnant women reduced serum copper and zinc concentrations in the second and third trimesters.

Trust comment: Randomized double-blind placebo-controlled trial (n=66) showing consistent biochemical changes but modest sample size.

Study Details

PMID:17963760
Participants:66
Impact:↓ significant decrease in supplemented group (P < 0.01 to P < 0.001)
Trust score:4/5

Malnourished children had lower blood zinc and copper; zinc levels correlated with linear growth.

Trust comment: Clinical observational measurements in 58 children with clear correlations reported but cross-sectional design and small sample limit causal inference.

Study Details

PMID:10829989
Participants:58
Impact:decreased in children with marked linear growth retardation
Trust score:3/5

acute diarrhoea (infants)

1 evidences

Pregnant women given 30 mg zinc vs placebo; infants (especially low-birthweight) had lower risks of acute diarrhea, dysentery, and impetigo by 6 months, but no growth or serum zinc differences.

Trust comment: Large, double-blind, placebo-controlled randomized trial with clear morbidity outcomes, though benefits limited to low-birthweight subgroup.

Study Details

PMID:11297959
Participants:420
Impact:risk ratio 0.84 (95% CI 0.72–0.98) reduction
Trust score:5/5

dysentery (infants)

1 evidences

Pregnant women given 30 mg zinc vs placebo; infants (especially low-birthweight) had lower risks of acute diarrhea, dysentery, and impetigo by 6 months, but no growth or serum zinc differences.

Trust comment: Large, double-blind, placebo-controlled randomized trial with clear morbidity outcomes, though benefits limited to low-birthweight subgroup.

Study Details

PMID:11297959
Participants:420
Impact:risk ratio 0.36 (95% CI 0.25–0.84) reduction
Trust score:5/5

impetigo (infants)

1 evidences

Pregnant women given 30 mg zinc vs placebo; infants (especially low-birthweight) had lower risks of acute diarrhea, dysentery, and impetigo by 6 months, but no growth or serum zinc differences.

Trust comment: Large, double-blind, placebo-controlled randomized trial with clear morbidity outcomes, though benefits limited to low-birthweight subgroup.

Study Details

PMID:11297959
Participants:420
Impact:risk ratio 0.53 (95% CI 0.34–0.82) reduction
Trust score:5/5

fasting plasma glucagon

1 evidences

After 1 year of 30 mg/day zinc or placebo, well-controlled type 2 diabetes patients showed no change in fasting or stimulated plasma glucagon or related ratios.

Trust comment: Small human study (n=28) with 1-year intervention in well-controlled diabetics; limited power but direct human evidence.

Study Details

PMID:29374382
Participants:28
Impact:no significant change with zinc vs placebo
Trust score:3/5

glucagon response to glucose/insulin infusion

1 evidences

After 1 year of 30 mg/day zinc or placebo, well-controlled type 2 diabetes patients showed no change in fasting or stimulated plasma glucagon or related ratios.

Trust comment: Small human study (n=28) with 1-year intervention in well-controlled diabetics; limited power but direct human evidence.

Study Details

PMID:29374382
Participants:28
Impact:no significant change with zinc vs placebo
Trust score:3/5

glucagon/glucose and glucagon/insulin ratios

1 evidences

After 1 year of 30 mg/day zinc or placebo, well-controlled type 2 diabetes patients showed no change in fasting or stimulated plasma glucagon or related ratios.

Trust comment: Small human study (n=28) with 1-year intervention in well-controlled diabetics; limited power but direct human evidence.

Study Details

PMID:29374382
Participants:28
Impact:no significant change with zinc vs placebo
Trust score:3/5

linear growth (knee height)

1 evidences

10-week, classroom-administered micronutrient/zinc supplementation in 6–9 year olds showed greatest growth when zinc was combined with other micronutrients and improved neuropsychological function with zinc-containing treatments.

Trust comment: Randomized double-blind classroom trial in 372 children with consistent effects on cognition and growth; short duration and cluster assignment may limit interpretation.

Study Details

PMID:9176834
Participants:372
Impact:zinc + micronutrients > micronutrients alone > zinc alone
Trust score:4/5

neuropsychological function

1 evidences

10-week, classroom-administered micronutrient/zinc supplementation in 6–9 year olds showed greatest growth when zinc was combined with other micronutrients and improved neuropsychological function with zinc-containing treatments.

Trust comment: Randomized double-blind classroom trial in 372 children with consistent effects on cognition and growth; short duration and cluster assignment may limit interpretation.

Study Details

PMID:9176834
Participants:372
Impact:improved with zinc-containing treatments (significant)
Trust score:4/5

IL-6 / maximal CPK index

1 evidences

Randomized open-label trial of polaprezinc (zinc compound) after AMI showed increased serum zinc, lower IL-6/max CPK index and improved left ventricular ejection fraction at 9 months versus control.

Trust comment: Randomized but open-label and small (n=50) with baseline imbalances; results suggest benefit but warrant larger trials.

Study Details

PMID:30855449
Participants:50
Impact:significantly decreased with polaprezinc (P=0.045)
Trust score:3/5

left ventricular ejection fraction (EF)

1 evidences

Randomized open-label trial of polaprezinc (zinc compound) after AMI showed increased serum zinc, lower IL-6/max CPK index and improved left ventricular ejection fraction at 9 months versus control.

Trust comment: Randomized but open-label and small (n=50) with baseline imbalances; results suggest benefit but warrant larger trials.

Study Details

PMID:30855449
Participants:50
Impact:increased from 54% to 62% in polaprezinc group (significant)
Trust score:3/5

skin radiance

1 evidences

Topical galvanic zinc-copper gel applied to photo-aged periorbital skin produced rapid and lasting visible improvements versus placebo.

Trust comment: Randomized double-blind placebo-controlled trial with 124 completers and reported statistical comparisons, supporting moderate-high reliability.

Study Details

PMID:22206074
Participants:124
Impact:significant improvement (visible from 15–30 min, sustained to 8 weeks)
Trust score:4/5

under-eye dark circles

1 evidences

Topical galvanic zinc-copper gel applied to photo-aged periorbital skin produced rapid and lasting visible improvements versus placebo.

Trust comment: Randomized double-blind placebo-controlled trial with 124 completers and reported statistical comparisons, supporting moderate-high reliability.

Study Details

PMID:22206074
Participants:124
Impact:significant improvement (rapid onset, sustained to 8 weeks)
Trust score:4/5

fine lines / under-eye wrinkles

1 evidences

Topical galvanic zinc-copper gel applied to photo-aged periorbital skin produced rapid and lasting visible improvements versus placebo.

Trust comment: Randomized double-blind placebo-controlled trial with 124 completers and reported statistical comparisons, supporting moderate-high reliability.

Study Details

PMID:22206074
Participants:124
Impact:significant improvement (noted from 2 weeks and continued to 8 weeks)
Trust score:4/5

remineralization (SMHR)

1 evidences

In an in situ crossover study, adding zinc to fluoride dentifrice reduced fluoride-driven remineralization measures but showed some increase in a demineralization-resistance metric.

Trust comment: Well-conducted randomized, examiner-blinded, 6-period crossover in situ study with clear statistical findings, though using bovine enamel limits direct clinical generalizability.

Study Details

PMID:29301123
Participants:62
Impact:reduced versus 1426 ppm F control (p<0.0001)
Trust score:4/5

enamel fluoride uptake (EFU)

1 evidences

In an in situ crossover study, adding zinc to fluoride dentifrice reduced fluoride-driven remineralization measures but showed some increase in a demineralization-resistance metric.

Trust comment: Well-conducted randomized, examiner-blinded, 6-period crossover in situ study with clear statistical findings, though using bovine enamel limits direct clinical generalizability.

Study Details

PMID:29301123
Participants:62
Impact:reduced versus 1426 ppm F control (p<0.0001)
Trust score:4/5

demineralization resistance (NAR/CAR)

1 evidences

In an in situ crossover study, adding zinc to fluoride dentifrice reduced fluoride-driven remineralization measures but showed some increase in a demineralization-resistance metric.

Trust comment: Well-conducted randomized, examiner-blinded, 6-period crossover in situ study with clear statistical findings, though using bovine enamel limits direct clinical generalizability.

Study Details

PMID:29301123
Participants:62
Impact:NAR reduced (p<0.0001) while CAR increased for Zn-A (p=0.004)
Trust score:4/5

zinc adherence (full-course)

1 evidences

Co-packaging zinc with ORS (especially with instructional messages) substantially increased adherence to zinc, ORS, and joint zinc+ORS treatment in children with diarrhea.

Trust comment: Large cluster-randomized trial (704 enrolled, 673 followed) with mixed-effects adjusted analyses and clear effect sizes, giving robust evidence for adherence effects.

Study Details

PMID:27246705
Participants:673
Impact:increased from 37.9% (status quo) to 65.9% (central) / 64.6% (HC level); +17.6 PP (central vs status quo) / +19.4 PP (HC vs status quo)
Trust score:4/5

ORS adherence

1 evidences

Co-packaging zinc with ORS (especially with instructional messages) substantially increased adherence to zinc, ORS, and joint zinc+ORS treatment in children with diarrhea.

Trust comment: Large cluster-randomized trial (704 enrolled, 673 followed) with mixed-effects adjusted analyses and clear effect sizes, giving robust evidence for adherence effects.

Study Details

PMID:27246705
Participants:673
Impact:increased from ~76.1% (status quo) to ~87.5–87.8% (central and HC level); +10–12 PP vs other arms
Trust score:4/5

joint zinc-ORS adherence

1 evidences

Co-packaging zinc with ORS (especially with instructional messages) substantially increased adherence to zinc, ORS, and joint zinc+ORS treatment in children with diarrhea.

Trust comment: Large cluster-randomized trial (704 enrolled, 673 followed) with mixed-effects adjusted analyses and clear effect sizes, giving robust evidence for adherence effects.

Study Details

PMID:27246705
Participants:673
Impact:increased from 71.6% (status quo) to 86.4% (central) / 86.5% (HC); +14.8 and +15.7 PP vs status quo
Trust score:4/5

CD4/CD8 and naive/memory T-cell ratios

1 evidences

Daily zinc plus micronutrient supplementation in children improved T-cell subset ratios and shifted cytokine production toward a more pro-inflammatory (Th1) profile with increased anti-inflammatory plasma receptors.

Trust comment: Double-blind randomized trial in children with measurable immunologic endpoints; small sample size but randomized design supports moderate confidence.

Study Details

PMID:18842795
Participants:54
Impact:increased (improved) after zinc + micronutrients vs micronutrients alone
Trust score:4/5

T-cell cytokine production (IL-2, IFN-γ)

1 evidences

Daily zinc plus micronutrient supplementation in children improved T-cell subset ratios and shifted cytokine production toward a more pro-inflammatory (Th1) profile with increased anti-inflammatory plasma receptors.

Trust comment: Double-blind randomized trial in children with measurable immunologic endpoints; small sample size but randomized design supports moderate confidence.

Study Details

PMID:18842795
Participants:54
Impact:increased ex vivo generation of IL-2 and IFN-γ with zinc + micronutrients
Trust score:4/5

anti-inflammatory plasma proteins (sIL-1ra, sTNF-R1) / IL-10

1 evidences

Daily zinc plus micronutrient supplementation in children improved T-cell subset ratios and shifted cytokine production toward a more pro-inflammatory (Th1) profile with increased anti-inflammatory plasma receptors.

Trust comment: Double-blind randomized trial in children with measurable immunologic endpoints; small sample size but randomized design supports moderate confidence.

Study Details

PMID:18842795
Participants:54
Impact:increased sIL-1ra and sTNF-R1 and decreased IL-10 with zinc + micronutrients
Trust score:4/5

dental plaque attachment rate

1 evidences

In this small pilot RCT in older adults, a zinc-containing glass ionomer coating tended to have lower material fall-out but produced no significant differences in plaque attachment or failure rates versus controls at 12 months.

Trust comment: Pilot randomized trial with small sample and limited power; randomized design is good but findings are inconclusive due to sample size and dropouts.

Study Details

PMID:38256410
Participants:47
Impact:no significant difference among zinc-GIC, conventional GIC, and NaF groups at 3–12 months (trend toward lower rates with GICs)
Trust score:3/5

failure rate (need for restoration)

1 evidences

In this small pilot RCT in older adults, a zinc-containing glass ionomer coating tended to have lower material fall-out but produced no significant differences in plaque attachment or failure rates versus controls at 12 months.

Trust comment: Pilot randomized trial with small sample and limited power; randomized design is good but findings are inconclusive due to sample size and dropouts.

Study Details

PMID:38256410
Participants:47
Impact:no significant difference among groups at 12 months (low but similar failure rates)
Trust score:3/5

coating material fall-out rate

1 evidences

In this small pilot RCT in older adults, a zinc-containing glass ionomer coating tended to have lower material fall-out but produced no significant differences in plaque attachment or failure rates versus controls at 12 months.

Trust comment: Pilot randomized trial with small sample and limited power; randomized design is good but findings are inconclusive due to sample size and dropouts.

Study Details

PMID:38256410
Participants:47
Impact:tended to be lower for zinc-containing GIC (Caredyne ZIF-C) vs Fuji VII (not statistically significant)
Trust score:3/5

plasma Cu/Zn ratio

1 evidences

Oral zinc supplementation in hemodialysis patients increased plasma zinc, reduced Cu/Zn ratio, decreased oxidative stress and inflammatory markers, and improved some nutritional and immune indices.

Trust comment: Preliminary randomized study with important exclusions and incomplete blinding; positive biologic signals but limited by reported exclusions and sample handling, so interpret cautiously.

Study Details

PMID:23289009
Participants:65
Impact:decreased (trend toward normalization) after 8 weeks of zinc supplementation
Trust score:3/5

oxidative stress markers (MDA, SOD)

1 evidences

Oral zinc supplementation in hemodialysis patients increased plasma zinc, reduced Cu/Zn ratio, decreased oxidative stress and inflammatory markers, and improved some nutritional and immune indices.

Trust comment: Preliminary randomized study with important exclusions and incomplete blinding; positive biologic signals but limited by reported exclusions and sample handling, so interpret cautiously.

Study Details

PMID:23289009
Participants:65
Impact:MDA decreased and erythrocyte SOD activity increased with zinc supplementation
Trust score:3/5

inflammatory markers and immune/nutritional indices (hs-CRP, TNF-α, IL-1β, hemoglobin, albumin)

1 evidences

Oral zinc supplementation in hemodialysis patients increased plasma zinc, reduced Cu/Zn ratio, decreased oxidative stress and inflammatory markers, and improved some nutritional and immune indices.

Trust comment: Preliminary randomized study with important exclusions and incomplete blinding; positive biologic signals but limited by reported exclusions and sample handling, so interpret cautiously.

Study Details

PMID:23289009
Participants:65
Impact:hs-CRP, TNF-α, IL-1β decreased; hemoglobin, albumin, and nPNA increased after zinc supplementation
Trust score:3/5

hemoglobin concentration

6 evidences

Randomized trial in 290 preschoolers: vitamin A + zinc improved height gains; multiple micronutrients yielded greater hemoglobin increases; serum zinc rose most in the vitamin A+zinc group.

Trust comment: Well-sized randomized trial with multiple arms and biologic endpoints, though full methodological details (blinding etc.) are limited in the summary.

Study Details

PMID:22374555
Participants:290
Impact:increased in all groups; largest incremental increase in multiple-micronutrient group (significant)
Trust score:4/5

Weekly or daily micronutrient supplements including zinc raised hemoglobin, serum zinc, and retinol versus placebo; growth improved only in children who were stunted at baseline.

Trust comment: Double-blind placebo-controlled trial with clear biomarker improvements and subgroup growth benefit; moderate sample size.

Study Details

PMID:9925127
Participants:163
Impact:increased in both daily and weekly supplement groups vs placebo (P < 0.001)
Trust score:4/5

Daily feeding with iron- and zinc-biofortified pearl millet did not change iron or zinc status or growth overall but raised hemoglobin in some subgroups (males and iron‑deficient children).

Trust comment: Large randomized controlled feeding trial with negative overall findings but plausible subgroup effects; well conducted.

Study Details

PMID:35299084
Participants:223
Impact:no significant change overall; increase in males and in iron‑deficient subgroup
Trust score:4/5

In infants, zinc increased risk of iron deficiency at 6 months while multivitamins reduced iron deficiency and lowered risk of severe anemia; zinc did not increase long-term anemia risk.

Trust comment: Large, double-blind randomized 2×2 factorial RCT (n>2000) with appropriate hematologic endpoints and rigorous analyses.

Study Details

PMID:28876332
Participants:2006
Impact:increased with multivitamin (+0.2 g/dL at 12 months; +0.3 g/dL at 18 months)
Trust score:5/5

Pooled data from four randomized trials in SE Asia showed combined iron+zinc reduced anemia and zinc deficiency but was less effective than single-nutrient supplements due to interactions.

Trust comment: Large pooled analysis of four randomized, placebo-controlled, double-blind trials (n=2468) across multiple countries providing strong evidence with clear statistical results.

Study Details

PMID:17237328
Participants:2468
Impact:zinc supplementation associated with a small decrease in hemoglobin (-2.5 g/L, P<0.001)
Trust score:5/5

In a 7-month cluster-RCT of fortified rice in Burundian schoolchildren, the intervention did not significantly increase hemoglobin or reduce anemia prevalence.

Trust comment: Large cluster-randomized controlled trial with appropriate outcomes, though high infection burden and formulation issues limited effect detection.

Study Details

PMID:26612421
Participants:904
Impact:no significant change (β = 0.09 g/dL; 95% CI -0.21 to 0.38)
Trust score:4/5

depression score (BDI)

1 evidences

In 100 adolescent girls, higher serum zinc was associated with slightly lower depression and anxiety scores.

Trust comment: Cross-sectional study of 100 students showing correlations (cannot infer causality).

Study Details

PMID:28064416
Participants:100
Impact:each +10 μg/dL serum zinc → −0.3 points in depression score (p<0.05)
Trust score:3/5

anxiety score (HADS)

1 evidences

In 100 adolescent girls, higher serum zinc was associated with slightly lower depression and anxiety scores.

Trust comment: Cross-sectional study of 100 students showing correlations (cannot infer causality).

Study Details

PMID:28064416
Participants:100
Impact:each +10 μg/dL serum zinc → −0.01 points in anxiety score (p<0.05)
Trust score:3/5

plasma ferritin

2 evidences

In 79 primary-school children given iron, zinc, or both for 4 months, serum zinc increased with zinc supplementation; effects on ferritin differed by regimen and plasma retinol decreased across supplemented groups.

Trust comment: Randomized double-blind trial with moderate sample size; results internally consistent though some biomarker changes are complex.

Study Details

PMID:19070056
Participants:79
Impact:iron+zinc associated with higher ferritin vs iron alone; zinc alone reported to decrease ferritin
Trust score:4/5

Analysis showed that acute phase responses (elevated CRP/AGP) substantially alter biomarkers of micronutrient status, inflating ferritin and distorting vitamin A and zinc indicators, which can misestimate deficiency prevalence.

Trust comment: Moderately large randomized supplementation trial dataset with measured acute phase proteins allowing valid assessment of biomarker confounding.

Study Details

PMID:12368396
Participants:418
Impact:+15.7 to +21.2 μg/L (higher with raised acute phase proteins)
Trust score:4/5

plasma retinol

2 evidences

Zinc supplementation increased plasma retinol and transthyretin in preschool children; RBP increase was not significant.

Trust comment: Double-blind, placebo-controlled randomized trial with clear biochemical outcomes and adequate sample.

Study Details

PMID:10702174
Participants:219
Impact:increased (significantly vs placebo)
Trust score:4/5

In 79 primary-school children given iron, zinc, or both for 4 months, serum zinc increased with zinc supplementation; effects on ferritin differed by regimen and plasma retinol decreased across supplemented groups.

Trust comment: Randomized double-blind trial with moderate sample size; results internally consistent though some biomarker changes are complex.

Study Details

PMID:19070056
Participants:79
Impact:decreased in all supplemented groups after 4 months
Trust score:4/5

urinary zinc

1 evidences

In 40 obese young women randomized to 30 mg/day zinc or placebo for 8 weeks, zinc raised serum and urinary zinc and reduced some inflammatory markers (hs-CRP, IL-6) but did not change leptin or adiponectin.

Trust comment: Controlled intervention with small groups and short duration; results plausible but sample size limits precision.

Study Details

PMID:24402636
Participants:40
Impact:increased by ~56% with supplementation (p<0.05)
Trust score:3/5

inflammatory markers (hs-CRP, IL-6)

1 evidences

In 40 obese young women randomized to 30 mg/day zinc or placebo for 8 weeks, zinc raised serum and urinary zinc and reduced some inflammatory markers (hs-CRP, IL-6) but did not change leptin or adiponectin.

Trust comment: Controlled intervention with small groups and short duration; results plausible but sample size limits precision.

Study Details

PMID:24402636
Participants:40
Impact:hs-CRP and IL-6 significantly decreased with zinc (hs-CRP p=0.03; IL-6 p=0.006); no change in placebo
Trust score:3/5

leptin and adiponectin

1 evidences

In 40 obese young women randomized to 30 mg/day zinc or placebo for 8 weeks, zinc raised serum and urinary zinc and reduced some inflammatory markers (hs-CRP, IL-6) but did not change leptin or adiponectin.

Trust comment: Controlled intervention with small groups and short duration; results plausible but sample size limits precision.

Study Details

PMID:24402636
Participants:40
Impact:no significant change with zinc
Trust score:3/5

median cold duration (experimental rhinovirus)

1 evidences

Two large randomized lozenge trials found zinc gluconate shortened median duration by ~1 day in experimental rhinovirus colds but zinc acetate had no effect; neither formulation affected natural colds.

Trust comment: Large randomized trials with mixed results (small benefit in one experimental arm only).

Study Details

PMID:11073753
Participants:554
Impact:zinc gluconate 2.5 days vs placebo 3.5 days (median; P=0.035)
Trust score:4/5

symptom severity

2 evidences

Two large randomized lozenge trials found zinc gluconate shortened median duration by ~1 day in experimental rhinovirus colds but zinc acetate had no effect; neither formulation affected natural colds.

Trust comment: Large randomized trials with mixed results (small benefit in one experimental arm only).

Study Details

PMID:11073753
Participants:554
Impact:zinc gluconate: no effect; zinc acetate: no effect on duration or severity
Trust score:4/5

Zinc nasal gel started within 24–48 h of cold onset shortened symptom duration and reduced symptom severity compared with placebo.

Trust comment: Randomized, double-blind placebo-controlled trial but relatively small sample (n=80) limits precision.

Study Details

PMID:12509647
Participants:80
Impact:reduced (significant from day 2; nasal drainage, congestion, hoarseness, sore throat)
Trust score:4/5

natural colds

1 evidences

Two large randomized lozenge trials found zinc gluconate shortened median duration by ~1 day in experimental rhinovirus colds but zinc acetate had no effect; neither formulation affected natural colds.

Trust comment: Large randomized trials with mixed results (small benefit in one experimental arm only).

Study Details

PMID:11073753
Participants:554
Impact:no effect of either zinc formulation on duration or severity
Trust score:4/5

fractional zinc absorption (FAZ) from MNP meals

1 evidences

In Kenyan infants (~9 months), iron in MNP did not affect zinc absorption, but overall zinc absorption from maize-based diets was low and often below physiologic requirement.

Trust comment: Randomized, double-blind isotope study with rigorous methods but limited completed sample size and high inflammatory burden.

Study Details

PMID:25493942
Participants:27
Impact:MNP+Fe 0.12±0.04; MNP−Fe 0.09±0.03; Control 0.25±0.04
Trust score:4/5

total absorbed zinc (TAZ, mg/day)

1 evidences

In Kenyan infants (~9 months), iron in MNP did not affect zinc absorption, but overall zinc absorption from maize-based diets was low and often below physiologic requirement.

Trust comment: Randomized, double-blind isotope study with rigorous methods but limited completed sample size and high inflammatory burden.

Study Details

PMID:25493942
Participants:27
Impact:MNP+Fe 0.85±0.22; MNP−Fe 0.72±0.19; Control 0.24±0.03 (MNP groups ≈physiologic requirement, control lower)
Trust score:4/5

time to be asymptomatic

1 evidences

In children (2–24 mo) with severe lower respiratory infection, 5 days of oral zinc did not shorten time to become symptom-free or meaningfully reduce hospital stay.

Trust comment: Triple-blind randomized placebo-controlled trial with balanced groups and clear null findings, moderate sample size.

Study Details

PMID:20882421
Participants:106
Impact:median 60 h (zinc) vs 54 h (placebo); P=0.98 (no difference)
Trust score:4/5

resolution of respiratory signs (distress, tachypnea, hypoxia)

1 evidences

In children (2–24 mo) with severe lower respiratory infection, 5 days of oral zinc did not shorten time to become symptom-free or meaningfully reduce hospital stay.

Trust comment: Triple-blind randomized placebo-controlled trial with balanced groups and clear null findings, moderate sample size.

Study Details

PMID:20882421
Participants:106
Impact:no difference between groups (no significant change)
Trust score:4/5

duration of hospital stay

2 evidences

In children (2–24 mo) with severe lower respiratory infection, 5 days of oral zinc did not shorten time to become symptom-free or meaningfully reduce hospital stay.

Trust comment: Triple-blind randomized placebo-controlled trial with balanced groups and clear null findings, moderate sample size.

Study Details

PMID:20882421
Participants:106
Impact:9 h shorter in zinc group (not statistically significant)
Trust score:4/5

Neonates with probable sepsis given zinc plus standard care had no significant change in mortality, hospital stay, or need for higher-line antibiotics.

Trust comment: Well-powered double-blind RCT with clear negative findings and balanced baseline characteristics.

Study Details

PMID:23255688
Participants:614
Impact:no significant difference (~142.85 hrs vs ~147.99 hrs; p=0.841)
Trust score:4/5

reported diarrhea incidence

1 evidences

In young Burkinabe children, daily preventive zinc raised plasma zinc and supplemented groups had modestly lower reported diarrhea and fever but slightly less linear growth over 16 weeks.

Trust comment: Large, cluster-randomized, masked community trial with pre-specified outcomes and plausible biologic measures (pZn).

Study Details

PMID:27489011
Participants:7641
Impact:0.48–0.49 vs 0.57 episodes/100 d (supplemented vs control); P=0.001 (reduced)
Trust score:5/5

length gain over 16 wk

1 evidences

In young Burkinabe children, daily preventive zinc raised plasma zinc and supplemented groups had modestly lower reported diarrhea and fever but slightly less linear growth over 16 weeks.

Trust comment: Large, cluster-randomized, masked community trial with pre-specified outcomes and plausible biologic measures (pZn).

Study Details

PMID:27489011
Participants:7641
Impact:3.15–3.20 cm (supplemented) vs 3.36 cm (control); P<0.001 (slightly less gain)
Trust score:5/5

safety/adverse events

2 evidences

Oral polaprezinc (zinc) at 68 mg/day improved taste sensitivity in patients with idiopathic taste disorders versus placebo.

Trust comment: GCP-compliant randomized, double-blind, placebo-controlled multi-center trial with dose-response finding and tolerable safety profile.

Study Details

PMID:19037756
Participants:109
Impact:No serious side effects; some increases in triglycerides/ALP and GI incidents (not serious)
Trust score:5/5

In hospitalized COVID-19 patients with low baseline zinc, high-dose IV zinc safely increased serum zinc above the deficiency cutoff by Day 6 with minimal local infusion irritation.

Trust comment: Randomized double-blind pilot with small sample and incomplete recruitment; shows biological correction of deficiency but underpowered for clinical outcomes.

Study Details

PMID:33629384
Participants:33
Impact:no serious adverse events; 3 participants had infusion site irritation (minor)
Trust score:3/5

length growth in anemic infants

1 evidences

In pooled infant trials, blanket zinc supplementation did not prevent overall growth faltering, but zinc reduced odds of stunting and improved length growth in anemic subgroups.

Trust comment: Large pooled randomized, placebo-controlled multicountry trials with pre-planned analyses and subgroup findings, though effects were subgroup-specific.

Study Details

PMID:18806109
Participants:2451
Impact:improved length growth in anemic infants (subgroup-specific benefit reported; magnitude not specified in text provided)
Trust score:5/5

infant weight at 12 months

1 evidences

Randomized prenatal zinc supplementation trial showing offspring of zinc-supplemented mothers had greater weight and measures of lean mass through 12 months but no change in linear growth.

Trust comment: Large randomized, double-blind prenatal trial with monthly follow-up of infants and adjusted longitudinal analyses; good internal validity.

Study Details

PMID:18614736
Participants:546
Impact:+0.58 kg (±0.12 kg), P < 0.001
Trust score:4/5

calf circumference

1 evidences

Randomized prenatal zinc supplementation trial showing offspring of zinc-supplemented mothers had greater weight and measures of lean mass through 12 months but no change in linear growth.

Trust comment: Large randomized, double-blind prenatal trial with monthly follow-up of infants and adjusted longitudinal analyses; good internal validity.

Study Details

PMID:18614736
Participants:546
Impact:+1.01 cm (±0.21 cm), P < 0.001
Trust score:4/5

calf muscle area

1 evidences

Randomized prenatal zinc supplementation trial showing offspring of zinc-supplemented mothers had greater weight and measures of lean mass through 12 months but no change in linear growth.

Trust comment: Large randomized, double-blind prenatal trial with monthly follow-up of infants and adjusted longitudinal analyses; good internal validity.

Study Details

PMID:18614736
Participants:546
Impact:+35.78 mm^2 (±14.75 mm^2), P = 0.01
Trust score:4/5

maternal serum zinc (28–30 wk)

1 evidences

Randomized prenatal supplementation showing mothers receiving added zinc had higher serum and urinary zinc in late pregnancy and neonates had higher cord blood zinc.

Trust comment: Large randomized prenatal trial with biochemical endpoints measured and appropriate adjustments; good evidence for improved zinc status though biomarker increases were modest.

Study Details

PMID:10357748
Participants:538
Impact:8.8 ± 1.9 vs 8.4 ± 1.5 μmol/L (zinc vs no zinc)
Trust score:4/5

maternal serum zinc (37–38 wk)

1 evidences

Randomized prenatal supplementation showing mothers receiving added zinc had higher serum and urinary zinc in late pregnancy and neonates had higher cord blood zinc.

Trust comment: Large randomized prenatal trial with biochemical endpoints measured and appropriate adjustments; good evidence for improved zinc status though biomarker increases were modest.

Study Details

PMID:10357748
Participants:538
Impact:8.6 ± 1.5 vs 8.3 ± 1.4 μmol/L (zinc vs no zinc)
Trust score:4/5

neonatal cord zinc

1 evidences

Randomized prenatal supplementation showing mothers receiving added zinc had higher serum and urinary zinc in late pregnancy and neonates had higher cord blood zinc.

Trust comment: Large randomized prenatal trial with biochemical endpoints measured and appropriate adjustments; good evidence for improved zinc status though biomarker increases were modest.

Study Details

PMID:10357748
Participants:538
Impact:12.7 ± 2.3 vs 12.1 ± 2.1 μmol/L (zinc vs no zinc, adjusted)
Trust score:4/5

continued breastfeeding at 18 months

1 evidences

Pooled analysis of four RCTs of small-quantity LNS (which include zinc among other micronutrients) showing no reduction in breastfeeding or major negative effects on feeding practices; some trials had increased feeding frequency and modest improvements in dietary diversity scores.

Trust comment: Large coordinated randomized trials with harmonized methods; outcomes are caregiver-reported which may introduce bias but overall high-quality trial evidence.

Study Details

PMID:27910260
Participants:5658
Impact:no change
Trust score:4/5

frequency of complementary feeding

1 evidences

Pooled analysis of four RCTs of small-quantity LNS (which include zinc among other micronutrients) showing no reduction in breastfeeding or major negative effects on feeding practices; some trials had increased feeding frequency and modest improvements in dietary diversity scores.

Trust comment: Large coordinated randomized trials with harmonized methods; outcomes are caregiver-reported which may introduce bias but overall high-quality trial evidence.

Study Details

PMID:27910260
Participants:5658
Impact:+12–14 percentage points in two trials (Burkina ZINC and DYAD-Malawi)
Trust score:4/5

low animal-source food score prevalence

1 evidences

Pooled analysis of four RCTs of small-quantity LNS (which include zinc among other micronutrients) showing no reduction in breastfeeding or major negative effects on feeding practices; some trials had increased feeding frequency and modest improvements in dietary diversity scores.

Trust comment: Large coordinated randomized trials with harmonized methods; outcomes are caregiver-reported which may introduce bias but overall high-quality trial evidence.

Study Details

PMID:27910260
Participants:5658
Impact:reduced (e.g., −19 percentage points in Burkina ZINC; −9 percentage points in DYAD-Malawi)
Trust score:4/5

time to clinical recovery (fever, tachypnea, appetite, cure status)

1 evidences

Double-blind RCT in children with severe measles and pneumonia found no additional clinical benefit from short-course zinc added to standard antibiotic and vitamin A therapy.

Trust comment: Randomized double-blind trial with balanced groups but short intervention and clinical setting limit generalizability; results consistently null.

Study Details

PMID:12198006
Participants:85
Impact:no difference between zinc and placebo groups
Trust score:4/5

serum zinc and retinol improvement after 6 days

1 evidences

Double-blind RCT in children with severe measles and pneumonia found no additional clinical benefit from short-course zinc added to standard antibiotic and vitamin A therapy.

Trust comment: Randomized double-blind trial with balanced groups but short intervention and clinical setting limit generalizability; results consistently null.

Study Details

PMID:12198006
Participants:85
Impact:no difference between groups
Trust score:4/5

child mortality

1 evidences

Daily 10 mg zinc given to young children in southern Nepal did not significantly reduce overall child mortality or common infections compared with placebo.

Trust comment: Large, cluster-randomized, double-masked, placebo-controlled trial with intention-to-treat analysis, high-quality evidence.

Study Details

PMID:17920918
Participants:41276
Impact:-8% (hazard ratio 0.92; not statistically significant)
Trust score:5/5

diarrhea frequency and duration

1 evidences

Daily 10 mg zinc given to young children in southern Nepal did not significantly reduce overall child mortality or common infections compared with placebo.

Trust comment: Large, cluster-randomized, double-masked, placebo-controlled trial with intention-to-treat analysis, high-quality evidence.

Study Details

PMID:17920918
Participants:41276
Impact:0% (no significant difference)
Trust score:5/5

acute lower respiratory infection incidence

1 evidences

Daily 10 mg zinc given to young children in southern Nepal did not significantly reduce overall child mortality or common infections compared with placebo.

Trust comment: Large, cluster-randomized, double-masked, placebo-controlled trial with intention-to-treat analysis, high-quality evidence.

Study Details

PMID:17920918
Participants:41276
Impact:0% (no significant difference)
Trust score:5/5

copper and iron status markers

1 evidences

Daily zinc (3–10 mg) for 6 months raised plasma zinc in a dose-dependent manner and reduced diarrhea incidence by ~21–42% without adverse effects on copper or iron markers.

Trust comment: Randomized, double-masked, community-based trial with adequate sample size and clear outcomes.

Study Details

PMID:18326612
Participants:631
Impact:0% (no adverse effects observed)
Trust score:5/5

serum copper level

2 evidences

In this phase 1 trial of VLBW preterm infants, serum zinc levels fell over 21 days in both groups, and human milk additives tested did not maintain serum zinc levels.

Trust comment: Phase 1 randomized, double-blind trial in humans but small sample (n=40) limits generalizability.

Study Details

PMID:39374901
Participants:40
Impact:0% (no significant change between or within groups)
Trust score:3/5

Zinc acetate hydrate (50 mg/day) increased serum zinc more than polaprezinc (34 mg/day) in maintenance hemodialysis patients and led to a decline in serum copper.

Trust comment: Prospective randomized trial with moderate sample size; open-label and single-center may limit generalizability.

Study Details

PMID:31794152
Participants:91
Impact:significant decrease with zinc acetate hydrate at 3 months
Trust score:4/5

difference between additives

1 evidences

In this phase 1 trial of VLBW preterm infants, serum zinc levels fell over 21 days in both groups, and human milk additives tested did not maintain serum zinc levels.

Trust comment: Phase 1 randomized, double-blind trial in humans but small sample (n=40) limits generalizability.

Study Details

PMID:39374901
Participants:40
Impact:0% (no intergroup difference)
Trust score:3/5

zinc status (biomarkers)

1 evidences

Probiotic-supplemented milk modestly improved growth (weight/height velocity) but had no effect on iron or zinc status in Indonesian children.

Trust comment: Large randomized trial with clear endpoints; intervention was probiotics in milk (indirectly measured zinc status).

Study Details

PMID:23700339
Participants:494
Impact:0% (no significant change)
Trust score:4/5

weight gain / growth velocity

1 evidences

Probiotic-supplemented milk modestly improved growth (weight/height velocity) but had no effect on iron or zinc status in Indonesian children.

Trust comment: Large randomized trial with clear endpoints; intervention was probiotics in milk (indirectly measured zinc status).

Study Details

PMID:23700339
Participants:494
Impact:modest increase (e.g., weight gain +0.22 kg vs control for L. reuteri; statistically significant)
Trust score:4/5

time to clinical recovery (fever/tachypnoea) and hospital duration

1 evidences

Short-course zinc (and vitamin A) given during hospitalisation for lower respiratory infection provided no clinical benefit and zinc was associated with higher readmission risk within 120 days.

Trust comment: Randomized 2x2 factorial RCT in a specific high-risk population; credible but moderate sample size.

Study Details

PMID:16460294
Participants:187
Impact:0% (no significant difference)
Trust score:4/5

readmission for ALRI within 120 days

1 evidences

Short-course zinc (and vitamin A) given during hospitalisation for lower respiratory infection provided no clinical benefit and zinc was associated with higher readmission risk within 120 days.

Trust comment: Randomized 2x2 factorial RCT in a specific high-risk population; credible but moderate sample size.

Study Details

PMID:16460294
Participants:187
Impact:+140% (relative risk 2.4; 95% CI 1.003–6.1)
Trust score:4/5

combined vitamin A + zinc effect

1 evidences

Short-course zinc (and vitamin A) given during hospitalisation for lower respiratory infection provided no clinical benefit and zinc was associated with higher readmission risk within 120 days.

Trust comment: Randomized 2x2 factorial RCT in a specific high-risk population; credible but moderate sample size.

Study Details

PMID:16460294
Participants:187
Impact:0% (no clinical benefit)
Trust score:4/5

clinical RDS severity (Down score, RDS grade)

1 evidences

In this RCT of neonates with RDS, zinc supplementation was associated with clinical and laboratory improvements by day 5 and shorter hospitalization and fewer needing mechanical ventilation.

Trust comment: Randomized trial with positive results but single-center, modest sample size, and limited methodological detail reported.

Study Details

PMID:34325645
Participants:90
Impact:improvement by day 5 (p = 0.001)
Trust score:3/5

inflammatory / oxidative markers (MDA, SOD, IL-8)

1 evidences

In this RCT of neonates with RDS, zinc supplementation was associated with clinical and laboratory improvements by day 5 and shorter hospitalization and fewer needing mechanical ventilation.

Trust comment: Randomized trial with positive results but single-center, modest sample size, and limited methodological detail reported.

Study Details

PMID:34325645
Participants:90
Impact:improvement by day 5 (p = 0.001)
Trust score:3/5

duration of hospitalization and need for mechanical ventilation

1 evidences

In this RCT of neonates with RDS, zinc supplementation was associated with clinical and laboratory improvements by day 5 and shorter hospitalization and fewer needing mechanical ventilation.

Trust comment: Randomized trial with positive results but single-center, modest sample size, and limited methodological detail reported.

Study Details

PMID:34325645
Participants:90
Impact:reduced hospitalization (p = 0.001); fewer required MV (p = 0.049)
Trust score:3/5

absorbed zinc (AZ)

1 evidences

Adding 10 mg zinc to a micronutrient powder markedly increased absorbed zinc and improved the exchangeable zinc pool in infants.

Trust comment: Nested randomized study using stable isotope methodology (≈38 infants); high-quality biochemical measures though sample size was small.

Study Details

PMID:24225451
Participants:38
Impact:+1.1 mg (0.1 ±0.1 vs 1.2 ±0.5 mg)
Trust score:4/5

maintenance of target serum zinc concentration (≥80 and <200 μg/dL for 8 weeks)

1 evidences

Randomized multicenter trial comparing two zinc formulations in patients with low serum zinc to test non-inferiority.

Trust comment: Large randomized multicenter non-inferiority trial in patients with hypozincemia; open-label but robust endpoints.

Study Details

PMID:39705879
Participants:210
Impact:NPC-25 86.4% vs NOBELZIN 80.4% (non-inferior)
Trust score:4/5

mean serum zinc concentration

2 evidences

Randomized multicenter trial comparing two zinc formulations in patients with low serum zinc to test non-inferiority.

Trust comment: Large randomized multicenter non-inferiority trial in patients with hypozincemia; open-label but robust endpoints.

Study Details

PMID:39705879
Participants:210
Impact:no significant difference between groups over time
Trust score:4/5

Large cluster-randomized trial: daily micronutrient Sprinkles (included zinc) plus feeding education reduced anemia and iron deficiency and increased mean serum zinc during the intervention period.

Trust comment: Large cluster-randomized effectiveness trial with objective biomarker outcomes; effects on zinc and anemia did not persist beyond intervention.

Study Details

PMID:22801933
Participants:3112
Impact:+2.88 μg/dL at 12 months
Trust score:4/5

digestive adverse events (nausea/vomiting)

1 evidences

Randomized multicenter trial comparing two zinc formulations in patients with low serum zinc to test non-inferiority.

Trust comment: Large randomized multicenter non-inferiority trial in patients with hypozincemia; open-label but robust endpoints.

Study Details

PMID:39705879
Participants:210
Impact:lower incidence with NPC-25 (nausea 2.8% vs 6.4%; vomiting 0.9% vs 2.8%)
Trust score:4/5

zinc balance

1 evidences

Randomized metabolic-diet study in adolescent females comparing long-term calcium supplementation versus placebo, measuring zinc balance and excretion over a 14-day metabolic period.

Trust comment: Controlled metabolic diet with direct balance measurements in humans, but small sample (n=26) and short measurement period.

Study Details

PMID:9129477
Participants:26
Impact:0.8 ± 0.8 mg/d (high Ca) vs 0.3 ± 1.1 mg/d (low Ca); P = 0.23 (no significant difference)
Trust score:4/5

vitamin A deficiency prevalence

1 evidences

Analysis showed that acute phase responses (elevated CRP/AGP) substantially alter biomarkers of micronutrient status, inflating ferritin and distorting vitamin A and zinc indicators, which can misestimate deficiency prevalence.

Trust comment: Moderately large randomized supplementation trial dataset with measured acute phase proteins allowing valid assessment of biomarker confounding.

Study Details

PMID:12368396
Participants:418
Impact:>16% overestimate when acute phase response present
Trust score:4/5

cord zinc relation to maternal plasma

1 evidences

Pregnant women taking iron-containing prenatal supplements had much lower fractional zinc absorption and lower plasma zinc than unsupplemented controls; adding zinc to prenatal supplements reduced this adverse effect.

Trust comment: Stable-isotope measurements in a defined cohort (n=47) with clear group comparisons; sample size modest.

Study Details

PMID:10958820
Participants:47
Impact:cord zinc concentrations positively related to maternal plasma zinc (r=0.486, P=0.002)
Trust score:4/5

fractional zinc absorption (FAZ)

2 evidences

In a crossover stable-isotope study in Kenyan preschoolers, adding ~16 g dried house crickets to maize porridge increased the amount of zinc absorbed compared with low-zinc porridge (and exceeded absorption from a high-Zn fortified meal).

Trust comment: Rigorous crossover stable-isotope study in young children with direct absorption measures; modest sample size and dropouts noted.

Study Details

PMID:39856054
Participants:25
Impact:LZ 15.2% (12.9–18.1) vs WC 13.8% (11.6–16.4) vs EC 12.6% (10.6–15.0) vs HZ 7.3% (6.1–8.8)
Trust score:4/5

Bangladeshi toddlers at risk of enteropathy had low zinc absorption; only higher MNP zinc doses (10–15 mg) produced mean absorbed zinc meeting estimated physiologic needs.

Trust comment: Well-conducted single-blind randomized dose study using stable isotopes with 74 completers and robust analyses.

Study Details

PMID:30624753
Participants:74
Impact:FAZ from MNP-containing meals remained low (0.06–0.07) vs 0.19 in 0 mg MNP group
Trust score:5/5

total absorbed zinc (TAZ)

3 evidences

Double-blind randomized crossover trial in Gambian children measuring fractional and total zinc absorption from porridge with SQ‑LNS with vs without added phytase using isotopic tracers.

Trust comment: High-quality double-blind crossover RCT using isotope tracers and objective endpoints, though small (n=26 completed).

Study Details

PMID:31504101
Participants:26
Impact:TAZ increased from 0.5 mg to 1.1 mg (+0.6 mg; P<0.001)
Trust score:5/5

In 9-month-old breastfed infants, meat or zinc-fortified cereal provided more absorbed zinc than iron-only fortified cereal; human-milk zinc contributed <25% of needs.

Trust comment: Randomized feeding trial with direct isotope-based zinc absorption measures but small sample size limits generalizability.

Study Details

PMID:22648720
Participants:45
Impact:meat 0.80 ± 0.08 mg/d, IZFC 0.71 ± 0.09 mg/d, IFC 0.52 ± 0.05 mg/d (TAZ higher in meat and IZFC vs IFC; P = 0.027)
Trust score:4/5

Bangladeshi toddlers at risk of enteropathy had low zinc absorption; only higher MNP zinc doses (10–15 mg) produced mean absorbed zinc meeting estimated physiologic needs.

Trust comment: Well-conducted single-blind randomized dose study using stable isotopes with 74 completers and robust analyses.

Study Details

PMID:30624753
Participants:74
Impact:means met physiologic requirement only in 10 mg (0.90 ± 0.43 mg/d) and 15 mg (1.00 ± 0.39 mg/d) MNP groups
Trust score:5/5

association with systemic inflammation

1 evidences

Bangladeshi toddlers at risk of enteropathy had low zinc absorption; only higher MNP zinc doses (10–15 mg) produced mean absorbed zinc meeting estimated physiologic needs.

Trust comment: Well-conducted single-blind randomized dose study using stable isotopes with 74 completers and robust analyses.

Study Details

PMID:30624753
Participants:74
Impact:serum AGP negatively associated with zinc absorption (P=0.007); E. histolytica infection also negatively associated (P=0.02)
Trust score:5/5

total daily zinc intake

1 evidences

Substituting biofortified maize increased children's zinc intake and total absorbed zinc compared with control maize, meeting requirements similarly to zinc-fortified maize.

Trust comment: Randomized feeding study with stable-isotope absorption measures in 60 children; outcomes directly relevant and statistically significant.

Study Details

PMID:25733467
Participants:60
Impact:increased to 5.0 ± 2.2 mg/d with biofortified maize vs 2.3 ± 0.9 mg/d control (P<0.0001)
Trust score:4/5

total daily absorbed zinc

1 evidences

Substituting biofortified maize increased children's zinc intake and total absorbed zinc compared with control maize, meeting requirements similarly to zinc-fortified maize.

Trust comment: Randomized feeding study with stable-isotope absorption measures in 60 children; outcomes directly relevant and statistically significant.

Study Details

PMID:25733467
Participants:60
Impact:increased to 1.1 ± 0.5 mg/d with biofortified maize vs 0.6 ± 0.2 mg/d control (P=0.0001)
Trust score:4/5

maternal serum zinc change

1 evidences

In women with gestational diabetes, 6 weeks of maternal zinc supplementation increased maternal serum zinc and raised PPAR-γ and GLUT1 mRNA levels in newborn umbilical cord blood compared with placebo.

Trust comment: Small randomized double-blind placebo-controlled trial with molecular endpoints in newborns; clear significant effects but limited sample size.

Study Details

PMID:27334434
Participants:40
Impact:increase of +11.1 ± 13.4 mg/dL with zinc vs −4.8 ± 17.3 mg/dL with placebo (P=0.002)
Trust score:4/5

PPAR-γ mRNA in cord blood

1 evidences

In women with gestational diabetes, 6 weeks of maternal zinc supplementation increased maternal serum zinc and raised PPAR-γ and GLUT1 mRNA levels in newborn umbilical cord blood compared with placebo.

Trust comment: Small randomized double-blind placebo-controlled trial with molecular endpoints in newborns; clear significant effects but limited sample size.

Study Details

PMID:27334434
Participants:40
Impact:significant increase with maternal zinc supplementation (P<0.001)
Trust score:4/5

GLUT1 mRNA in cord blood

1 evidences

In women with gestational diabetes, 6 weeks of maternal zinc supplementation increased maternal serum zinc and raised PPAR-γ and GLUT1 mRNA levels in newborn umbilical cord blood compared with placebo.

Trust comment: Small randomized double-blind placebo-controlled trial with molecular endpoints in newborns; clear significant effects but limited sample size.

Study Details

PMID:27334434
Participants:40
Impact:significant increase with maternal zinc supplementation (P<0.001)
Trust score:4/5

ORS use

1 evidences

In young children with acute watery diarrhea, zinc (20 mg daily for 14 days) plus ORS had high adherence, did not reduce ORS use, and modestly reduced use of antibiotics/antidiarrheals.

Trust comment: Large multicenter randomized trial with low loss to follow-up and clear outcomes, high confidence in results.

Study Details

PMID:16540790
Participants:2002
Impact:no decrease; similar or higher in zinc group on days 3–5
Trust score:5/5

fasting plasma glucose

5 evidences

Daily antioxidant capsule containing 20 mg zinc (among other antioxidants) for 7.5 years had no effect on fasting plasma glucose compared with placebo.

Trust comment: Large, long-duration randomized trial with robust sample size and clear null result for FPG.

Study Details

PMID:16895889
Participants:3146
Impact:no significant difference after 7.5 years in men (P = 0.78) or women (P = 0.89)
Trust score:5/5

Eight weeks of daily zinc (20 mg) in obese prepubertal children reduced fasting glucose, insulin and insulin resistance.

Trust comment: Triple-masked randomized placebo-controlled crossover trial with objective metabolic measures but modest sample size.

Study Details

PMID:20045801
Participants:60
Impact:↓ (significant) after zinc vs baseline/placebo
Trust score:4/5

Pregnant women with gestational diabetes took zinc or placebo for 6 weeks; zinc improved blood sugar control and some lipids.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear biochemical outcomes but modest sample size (n=58).

Study Details

PMID:26233572
Participants:58
Impact:-6.6 ±11.2 mg/dL (zinc) vs +0.6 ±6.7 mg/dL (placebo); P=0.005
Trust score:4/5

Diabetic patients with foot ulcers given zinc for 12 weeks had smaller ulcers and improved blood sugar control, insulin resistance, HDL, and inflammation markers versus placebo.

Trust comment: Small randomized, double-blind trial showing multiple metabolic and wound-healing benefits, but limited sample size.

Study Details

PMID:28395131
Participants:60
Impact:reduced (-40.5 mg/dl vs -3.9 mg/dl; p=0.02)
Trust score:4/5

Six weeks of magnesium-zinc-calcium-vitamin D co-supplementation in gestational diabetes improved fasting glucose, insulin-related markers and some lipid markers versus placebo.

Trust comment: Randomized double-blind trial with clear metabolic endpoints, but zinc was given as part of a multi-nutrient supplement so individual zinc effects are not isolated.

Study Details

PMID:29316405
Participants:60
Impact:-0.37 ±0.09 mmol/L vs +0.01 ±0.09 mmol/L (P=0.003)
Trust score:4/5

insulin resistance (HOMA-IR)

2 evidences

In adults with prediabetes, 20 mg/day zinc reduced progression to type 2 diabetes and improved glycemic and some lipid measures over 12 months.

Trust comment: Randomized, double-blind, placebo-controlled trial (n=200) with clear endpoints and statistically significant results.

Study Details

PMID:29072815
Participants:200
Impact:decreased (significant); β-cell function increased (significant)
Trust score:5/5

Pregnant women with gestational diabetes took zinc or placebo for 6 weeks; zinc improved blood sugar control and some lipids.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear biochemical outcomes but modest sample size (n=58).

Study Details

PMID:26233572
Participants:58
Impact:-0.5 ±1.6 (zinc) vs +1.5 ±2.7 (placebo); P=0.001
Trust score:4/5

age at menarche

1 evidences

Compared girls with sickle cell disease to matched controls; lower zinc was linked to later puberty and later first menstruation.

Trust comment: Cross-sectional case-control study with clear associations but cannot prove causation and potential confounding.

Study Details

PMID:29870301
Participants:162
Impact:Subjects mean 14.81 ±1.07 years vs controls 12.62 ±1.18 years; P=0.001 (+2.19 years)
Trust score:3/5

sexual maturation (Tanner stage attainment)

1 evidences

Compared girls with sickle cell disease to matched controls; lower zinc was linked to later puberty and later first menstruation.

Trust comment: Cross-sectional case-control study with clear associations but cannot prove causation and potential confounding.

Study Details

PMID:29870301
Participants:162
Impact:Significant delay in attainment of breast and pubic hair Tanner stages in SCA subjects (directional, P reported)
Trust score:3/5

weight and length gain

1 evidences

Preterm infants given zinc plus multivitamin grew more and had higher zinc levels and fewer illnesses over 6 weeks compared to multivitamin alone.

Trust comment: Randomized controlled trial with 100 preterm infants and objective biochemical and clinical outcomes; short follow-up and some endpoints not fully quantified in the excerpt.

Study Details

PMID:20308765
Participants:100
Impact:Increased weight and length increments in zinc group (reported improvement; no exact values in excerpt)
Trust score:4/5

morbidity (illness frequency)

1 evidences

Preterm infants given zinc plus multivitamin grew more and had higher zinc levels and fewer illnesses over 6 weeks compared to multivitamin alone.

Trust comment: Randomized controlled trial with 100 preterm infants and objective biochemical and clinical outcomes; short follow-up and some endpoints not fully quantified in the excerpt.

Study Details

PMID:20308765
Participants:100
Impact:Reduction of morbidity apparent in zinc supplemented group (directional, not fully quantified in excerpt)
Trust score:4/5

net zinc absorption

1 evidences

Randomized metabolic-diet study in adolescent females comparing long-term calcium supplementation versus placebo, measuring zinc balance and excretion over a 14-day metabolic period.

Trust comment: Controlled metabolic diet with direct balance measurements in humans, but small sample (n=26) and short measurement period.

Study Details

PMID:9129477
Participants:26
Impact:21% (high Ca) vs 15% (low Ca); P = 0.33 (no significant difference)
Trust score:4/5

relapse rate (per patient per year)

1 evidences

Children with nephrotic syndrome given zinc for 6 months had fewer relapses afterward compared with their pre-study rate and slightly more reduction than placebo.

Trust comment: Randomized-controlled trial with 54 completers; modest size and some outcomes showed improvements but infection differences were not significant.

Study Details

PMID:24491005
Participants:54
Impact:Zinc group decreased from 2.71 (pre) to 1.14 ±0.37 (post) (~43% reduction); placebo decreased from 1.70 to 1.30 ±0.48 (~27% reduction)
Trust score:3/5

Infection frequency

1 evidences

Children with nephrotic syndrome given zinc for 6 months had fewer relapses afterward compared with their pre-study rate and slightly more reduction than placebo.

Trust comment: Randomized-controlled trial with 54 completers; modest size and some outcomes showed improvements but infection differences were not significant.

Study Details

PMID:24491005
Participants:54
Impact:No significant difference between zinc and placebo groups (no effect)
Trust score:3/5

weight/height (anthropometry)

1 evidences

Children aged 1–5 years received 10 mg/day zinc for 4 months; zinc normalized serum zinc and improved hemoglobin but did not change growth measures.

Trust comment: Blinded randomized clinical trial with small sample (n=58); biochemical improvements clear but anthropometric responses absent.

Study Details

PMID:16738738
Participants:58
Impact:No remarkable influence on weight-for-height or height-for-age z scores (no effect)
Trust score:3/5

intellectual function

1 evidences

Giving zinc in preschool did not change thinking, motor skills, or executive function at age 7–9.

Trust comment: Large randomized placebo-controlled factorial trial with long follow-up, but adjusted analyses showed no effect.

Study Details

PMID:22566538
Participants:734
Impact:no significant effect at 7–9 years
Trust score:4/5

motor function

1 evidences

Giving zinc in preschool did not change thinking, motor skills, or executive function at age 7–9.

Trust comment: Large randomized placebo-controlled factorial trial with long follow-up, but adjusted analyses showed no effect.

Study Details

PMID:22566538
Participants:734
Impact:no significant effect at 7–9 years
Trust score:4/5

executive function

1 evidences

Giving zinc in preschool did not change thinking, motor skills, or executive function at age 7–9.

Trust comment: Large randomized placebo-controlled factorial trial with long follow-up, but adjusted analyses showed no effect.

Study Details

PMID:22566538
Participants:734
Impact:no significant effect at 7–9 years
Trust score:4/5

anemia recovery rate

2 evidences

Daily sprinkles containing multiple micronutrients (including 5 mg zinc) improved anemia recovery versus placebo but did not prevent declines in growth z-scores.

Trust comment: Randomized controlled trial (n=204) but zinc was provided as part of a multi-micronutrient mix, limiting attribution of effects specifically to zinc.

Study Details

PMID:16540800
Participants:204
Impact:MMN (with zinc) 54% recovery vs placebo 22% (end of study)
Trust score:3/5

Both iron alone and iron+zinc sachets treated anemia, but adding zinc lowered anemia recovery rate and did not improve zinc status or growth.

Trust comment: Controlled intervention with a sizable sample of anemic infants, though interactions between nutrients complicate interpretation.

Study Details

PMID:12672922
Participants:304
Impact:Fe 74.8% vs Fe+Zn 62.9% (Fe better; P = 0.048)
Trust score:4/5

height-for-age Z-score

1 evidences

Both iron alone and iron+zinc sachets treated anemia, but adding zinc lowered anemia recovery rate and did not improve zinc status or growth.

Trust comment: Controlled intervention with a sizable sample of anemic infants, though interactions between nutrients complicate interpretation.

Study Details

PMID:12672922
Participants:304
Impact:significant decline in Fe+Zn group (P = 0.0011); no change in Fe group
Trust score:4/5

linear growth (initially-stunted)

1 evidences

Zinc combined with iron (with or without vitamin A) improved growth and micronutrient status in stunted infants, whereas zinc alone worsened iron/hemoglobin markers and growth trajectory.

Trust comment: Large double-blind community RCT with clear subgroup effects (stunted, low hemoglobin), supporting internal validity.

Study Details

PMID:17468087
Participants:800
Impact:Zn+Fe and Zn+Fe+vitA groups grew 1.1–1.5 cm more than placebo
Trust score:4/5

hemoglobin/iron status

1 evidences

Zinc combined with iron (with or without vitamin A) improved growth and micronutrient status in stunted infants, whereas zinc alone worsened iron/hemoglobin markers and growth trajectory.

Trust comment: Large double-blind community RCT with clear subgroup effects (stunted, low hemoglobin), supporting internal validity.

Study Details

PMID:17468087
Participants:800
Impact:Zn-alone disadvantaged hemoglobin and iron; Zn+Fe and Zn+Fe+vitA improved iron status
Trust score:4/5

phagocytic activity

1 evidences

Zinc treatment/supplementation in children with ETEC diarrhea increased serum zinc and some innate immune markers (complement C3, phagocytosis) but reduced oxidative burst capacity.

Trust comment: Well-sized clinical follow-up with immunologic measures and clear statistical differences, though some immune changes are complex to interpret.

Study Details

PMID:20237063
Participants:248
Impact:increased in zinc groups vs untreated (P < 0.01)
Trust score:4/5

oxidative burst capacity

1 evidences

Zinc treatment/supplementation in children with ETEC diarrhea increased serum zinc and some innate immune markers (complement C3, phagocytosis) but reduced oxidative burst capacity.

Trust comment: Well-sized clinical follow-up with immunologic measures and clear statistical differences, though some immune changes are complex to interpret.

Study Details

PMID:20237063
Participants:248
Impact:decreased in zinc groups vs untreated (P < 0.001)
Trust score:4/5

pressure ulcer area reduction

1 evidences

Randomized blinded trial in malnourished adults with pressure ulcers found an arginine-/zinc-/antioxidant‑enriched high-calorie formula improved ulcer area reduction versus isocaloric control over 8 weeks.

Trust comment: Well-conducted multicenter RCT, but zinc was one component of a multi-nutrient formula so effects cannot be attributed to zinc alone.

Study Details

PMID:25643304
Participants:200
Impact:Enriched formula mean reduction 60.9% vs control 45.2%; adjusted mean difference +18.7% (95% CI 5.7% to 31.8%; P=0.017)
Trust score:3/5

fetal heart rate (FHR)

1 evidences

Prenatal zinc supplements in zinc‑deficient mothers were linked to more mature fetal heart rate patterns.

Trust comment: Double-blind randomized controlled trial with good completion (195 completers) indicating physiological fetal effects in a zinc‑deficient population.

Study Details

PMID:15118650
Participants:195
Impact:lower FHR with zinc supplementation
Trust score:4/5

fetal heart rate variability (HRV)

1 evidences

Prenatal zinc supplements in zinc‑deficient mothers were linked to more mature fetal heart rate patterns.

Trust comment: Double-blind randomized controlled trial with good completion (195 completers) indicating physiological fetal effects in a zinc‑deficient population.

Study Details

PMID:15118650
Participants:195
Impact:increased HRV with zinc supplementation (effects stronger after 28 weeks)
Trust score:4/5

fetal accelerations

1 evidences

Prenatal zinc supplements in zinc‑deficient mothers were linked to more mature fetal heart rate patterns.

Trust comment: Double-blind randomized controlled trial with good completion (195 completers) indicating physiological fetal effects in a zinc‑deficient population.

Study Details

PMID:15118650
Participants:195
Impact:greater number of accelerations with zinc supplementation
Trust score:4/5

zinc absorption

4 evidences

Different modes/amounts of oral iron did not change zinc absorption, zinc status, or growth in iron-sufficient infants.

Trust comment: Randomized trial with isotopic measures and objective endpoints, clear null results.

Study Details

PMID:27546308
Participants:72
Impact:no change (no intervention effect observed)
Trust score:4/5

In healthy breastfed infants, prior iron supplementation did not change zinc absorption or plasma zinc between 6 and 9 months.

Trust comment: Small sample but uses stable isotope absorption measures and objective endpoints; results consistent and specific.

Study Details

PMID:19056575
Participants:25
Impact:no change with iron supplementation (mean ~51.9% overall)
Trust score:4/5

Processing (hydrothermal treatment or malting) of barley increased zinc absorption from meals in healthy volunteers, while calcium absorption was unchanged.

Trust comment: Objective isotopic whole-body retention measures in healthy volunteers, but small sample size.

Study Details

PMID:14647214
Participants:22
Impact:increased (hydrothermally treated porridge 21.1% vs 19.5% control; +1.6 percentage points, significant); malted barley also increased zinc absorption (significant)
Trust score:4/5

Adding Na2EDTA to fortified rice flour increased iron and zinc absorption in schoolchildren.

Trust comment: Randomized trial with tracer-based absorption measures and reasonable completion rate, but moderate sample size.

Study Details

PMID:15514271
Participants:48
Impact:13.5% vs 8.8% (increase; P = 0.037)
Trust score:4/5

time to cessation of severe pneumonia

1 evidences

Adding 20 mg zinc per day to standard treatment shortened duration of severe pneumonia and hospital stay by about one day in young children.

Trust comment: Double-blind placebo-controlled RCT with clear clinical outcomes and a reasonable sample size strengthens confidence in the effect.

Study Details

PMID:15158629
Participants:270
Impact:reduced (relative hazard=0.70; faster recovery)
Trust score:4/5

Hospital length of stay

2 evidences

Perioperative zinc plus vitamin E supplementation increased plasma zinc, reduced inflammatory markers, and shortened hospital length of stay after CABG surgery.

Trust comment: Randomized double-blind trial with clear clinical and biomarker outcomes, but supplementation combined zinc with vitamin E.

Study Details

PMID:37891226
Participants:78
Impact:decreased (p<0.05)
Trust score:4/5

Adding 20 mg zinc per day to standard treatment shortened duration of severe pneumonia and hospital stay by about one day in young children.

Trust comment: Double-blind placebo-controlled RCT with clear clinical outcomes and a reasonable sample size strengthens confidence in the effect.

Study Details

PMID:15158629
Participants:270
Impact:reduced (relative hazard=0.75; mean ~1 day shorter)
Trust score:4/5

duration of specific severity signs (e.g., tachypnea, hypoxia, chest indrawing)

1 evidences

Adding 20 mg zinc per day to standard treatment shortened duration of severe pneumonia and hospital stay by about one day in young children.

Trust comment: Double-blind placebo-controlled RCT with clear clinical outcomes and a reasonable sample size strengthens confidence in the effect.

Study Details

PMID:15158629
Participants:270
Impact:reduced (RH range ~0.74–0.80; effects larger when wheezy children excluded)
Trust score:4/5

24-hour urinary zinc excretion

1 evidences

Treatment with captopril or enalapril altered zinc measures: captopril increased urinary zinc loss and both drugs lowered monocyte zinc.

Trust comment: Randomized allocation but small groups and limited detail; findings suggest ACE inhibitors affect zinc metabolism in treated hypertensive patients.

Study Details

PMID:9477394
Participants:44
Impact:increased significantly after 6 months in captopril-treated patients
Trust score:3/5

intramonocytic zinc levels

1 evidences

Treatment with captopril or enalapril altered zinc measures: captopril increased urinary zinc loss and both drugs lowered monocyte zinc.

Trust comment: Randomized allocation but small groups and limited detail; findings suggest ACE inhibitors affect zinc metabolism in treated hypertensive patients.

Study Details

PMID:9477394
Participants:44
Impact:decreased significantly in both captopril and enalapril groups over 6 months
Trust score:3/5

persistence of diarrhea / time to cessation

1 evidences

Oral zinc supplementation in adults with HIV and persistent diarrhea did not significantly shorten diarrhea duration or increase remission.

Trust comment: Randomized placebo-controlled trial but with high loss to follow-up and baseline differences in enteric pathogens, limiting confidence in null result.

Study Details

PMID:16940855
Participants:159
Impact:no significant effect on duration or remission (HR for cessation 0.91, 95% CI 0.50–1.64)
Trust score:3/5

zinc status at follow-up

1 evidences

Oral zinc supplementation in adults with HIV and persistent diarrhea did not significantly shorten diarrhea duration or increase remission.

Trust comment: Randomized placebo-controlled trial but with high loss to follow-up and baseline differences in enteric pathogens, limiting confidence in null result.

Study Details

PMID:16940855
Participants:159
Impact:improved in zinc group (zinc deficiency: 66% zinc vs 94% placebo at follow-up; P=0.01)
Trust score:3/5

total absorbed zinc

1 evidences

Ten-week feeding trial found no significant differences in fractional or total absorbed zinc between low-phytate and control maize groups.

Trust comment: Randomized feeding trial with objective isotope-based absorption measures but small group sizes limit power to detect modest effects.

Study Details

PMID:16400050
Participants:60
Impact:no significant difference between maize groups (2.72, 2.30, 2.78 mg/d respectively)
Trust score:3/5

total body iron

1 evidences

In a 3-month randomized double-blind trial, daily 30 mg iron plus 30 mg zinc improved hemoglobin, total body iron and serum zinc versus placebo in women of childbearing age.

Trust comment: Randomized double-blind trial with moderate sample size and clinically relevant biochemical outcomes.

Study Details

PMID:25582309
Participants:81
Impact:significant increase vs placebo
Trust score:4/5

oxidative damage markers

1 evidences

In 40 men with type 2 diabetes and normal zinc status, high-dose zinc raised serum zinc but did not change oxidative damage markers or vascular function over 3 months.

Trust comment: Randomized placebo-controlled study with objective biomarkers; limited by small sample and single population (men with normal zinc).

Study Details

PMID:21840002
Participants:40
Impact:no change
Trust score:4/5

vascular function indices

1 evidences

In 40 men with type 2 diabetes and normal zinc status, high-dose zinc raised serum zinc but did not change oxidative damage markers or vascular function over 3 months.

Trust comment: Randomized placebo-controlled study with objective biomarkers; limited by small sample and single population (men with normal zinc).

Study Details

PMID:21840002
Participants:40
Impact:no change
Trust score:4/5

height gain

2 evidences

Thai schoolchildren given zinc plus multivitamins (which included vitamin D) for 6 months had greater height gain than placebo.

Trust comment: Randomized controlled trial with adequate sample and clear, clinically relevant height outcome.

Study Details

PMID:27083763
Participants:140
Impact:4.9 ± 1.3 cm (zinc+multivitamin) vs 3.6 ± 0.9 cm (placebo); P < 0.001
Trust score:4/5

In growth-retarded preschool children, zinc (±calcium) supplementation increased annual height gain, vitamin A-containing regimens improved weight gain, and supplementation reduced days of illness.

Trust comment: Double-blind placebo-controlled trial with adequate sample size and clinically meaningful growth outcomes.

Study Details

PMID:12500659
Participants:156
Impact:+1.10 cm/year (+Zn 7.84 vs control 6.74 cm/year)
Trust score:4/5

days of illness

1 evidences

In growth-retarded preschool children, zinc (±calcium) supplementation increased annual height gain, vitamin A-containing regimens improved weight gain, and supplementation reduced days of illness.

Trust comment: Double-blind placebo-controlled trial with adequate sample size and clinically meaningful growth outcomes.

Study Details

PMID:12500659
Participants:156
Impact:−10 days/year (13 vs 23 days)
Trust score:4/5

diarrhea days

1 evidences

Two weeks of zinc given during acute diarrhea in infants under 6 months did not improve growth or reduce infections and was associated with more days of diarrhea.

Trust comment: Large randomized trial in infants with clear outcomes and adequate sample size, results likely reliable.

Study Details

PMID:17344513
Participants:1074
Impact:+20% (rate ratio = 1.20)
Trust score:4/5

diarrhea incidence/prevalence

1 evidences

Two weeks of zinc given during acute diarrhea in infants under 6 months did not improve growth or reduce infections and was associated with more days of diarrhea.

Trust comment: Large randomized trial in infants with clear outcomes and adequate sample size, results likely reliable.

Study Details

PMID:17344513
Participants:1074
Impact:no significant change
Trust score:4/5

growth (weight/length z-scores)

1 evidences

Two weeks of zinc given during acute diarrhea in infants under 6 months did not improve growth or reduce infections and was associated with more days of diarrhea.

Trust comment: Large randomized trial in infants with clear outcomes and adequate sample size, results likely reliable.

Study Details

PMID:17344513
Participants:1074
Impact:no significant change
Trust score:4/5

insulin concentration

1 evidences

Thirty milligrams of zinc daily for 4 weeks lowered insulin and insulin resistance (HOMA) in obese women but did not change leptin or BMI.

Trust comment: Double-blind randomized placebo-controlled trial but small sample (n=56); biochemical outcomes measured directly.

Study Details

PMID:17028377
Participants:56
Impact:decrease (significant)
Trust score:4/5

insulin resistance (HOMA)

1 evidences

Thirty milligrams of zinc daily for 4 weeks lowered insulin and insulin resistance (HOMA) in obese women but did not change leptin or BMI.

Trust comment: Double-blind randomized placebo-controlled trial but small sample (n=56); biochemical outcomes measured directly.

Study Details

PMID:17028377
Participants:56
Impact:−1.5 absolute (from 5.8 to 4.3; ≈26% decrease)
Trust score:4/5

leptin

1 evidences

Thirty milligrams of zinc daily for 4 weeks lowered insulin and insulin resistance (HOMA) in obese women but did not change leptin or BMI.

Trust comment: Double-blind randomized placebo-controlled trial but small sample (n=56); biochemical outcomes measured directly.

Study Details

PMID:17028377
Participants:56
Impact:no significant change
Trust score:4/5

length gain

3 evidences

Two-week zinc (20 mg/d) during acute diarrhoea improved subsequent linear growth and reduced diarrhoea and respiratory episodes in malnourished subgroups over 8 weeks.

Trust comment: Double-blind RCT in malnourished children with clear outcome measures but modest sample size.

Study Details

PMID:10452407
Participants:65
Impact:+4.4 mm cumulative length gain (18.9 vs 14.5 mm)
Trust score:4/5

Short-term zinc (with/without vitamin A) did not affect weight or length gains over 6 months in undernourished children.

Trust comment: Large randomized double-blind placebo-controlled trial with adequate follow-up showing null effect on growth.

Study Details

PMID:11756064
Participants:653
Impact:no significant change
Trust score:4/5

Low birth weight infants given daily zinc had greater weight, length and head circumference gains by 6 months compared with placebo.

Trust comment: Randomized placebo-controlled trial with monthly anthropometry; moderate sample of completers but some attrition.

Study Details

PMID:21858548
Participants:76
Impact:greater length gain: 16.9 ± 8.2 cm (zinc) vs 15.1 ± 4.1 cm (placebo) (P=0.039)
Trust score:4/5

catch-up growth (weight-for-age and length-for-age z-scores)

1 evidences

Short-term zinc (with/without vitamin A) did not affect weight or length gains over 6 months in undernourished children.

Trust comment: Large randomized double-blind placebo-controlled trial with adequate follow-up showing null effect on growth.

Study Details

PMID:11756064
Participants:653
Impact:no significant change
Trust score:4/5

plasma copper concentration

2 evidences

Daily cashew consumption for 12 weeks in adolescents with obesity reduced plasma copper and increased erythrocyte SOD activity; plasma zinc increased across both groups (likely influenced by counseling).

Trust comment: Randomized controlled trial but with substantial dropout and potential confounding from concurrent nutritional counseling; objective biochemical endpoints measured.

Study Details

PMID:39796597
Participants:81
Impact:CASN group Δ = −6.34 µg/dL (significantly different from CON Δ = +3.61 µg/dL; p=0.004)
Trust score:4/5

Four months of 10 mg/day zinc in infants raised plasma zinc but did not change plasma copper or hematological markers of copper status.

Trust comment: Randomized controlled sub-study with direct biochemical measures showing clear increase in zinc and no change in copper or blood indices.

Study Details

PMID:15174779
Participants:115
Impact:no significant change
Trust score:4/5

hematological markers (Hgb, MCV, MCHC, lymphocytes/granulocytes)

1 evidences

Four months of 10 mg/day zinc in infants raised plasma zinc but did not change plasma copper or hematological markers of copper status.

Trust comment: Randomized controlled sub-study with direct biochemical measures showing clear increase in zinc and no change in copper or blood indices.

Study Details

PMID:15174779
Participants:115
Impact:no significant change
Trust score:4/5

genitourinary hospital admissions

1 evidences

In a large randomized trial, high-dose zinc supplementation increased hospital admissions for genitourinary problems, including UTIs and urinary retention/stone events.

Trust comment: Large randomized trial (secondary analysis) with significant and clinically relevant increases in GU admissions associated with high-dose zinc.

Study Details

PMID:17222649
Participants:3640
Impact:+3.5 percentage points (11.1% vs 7.6%)
Trust score:4/5

urinary tract infections (females)

1 evidences

In a large randomized trial, high-dose zinc supplementation increased hospital admissions for genitourinary problems, including UTIs and urinary retention/stone events.

Trust comment: Large randomized trial (secondary analysis) with significant and clinically relevant increases in GU admissions associated with high-dose zinc.

Study Details

PMID:17222649
Participants:3640
Impact:+1.9 percentage points (2.3% vs 0.4%); RR 5.77
Trust score:4/5

urinary lithiasis (men)

1 evidences

In a large randomized trial, high-dose zinc supplementation increased hospital admissions for genitourinary problems, including UTIs and urinary retention/stone events.

Trust comment: Large randomized trial (secondary analysis) with significant and clinically relevant increases in GU admissions associated with high-dose zinc.

Study Details

PMID:17222649
Participants:3640
Impact:increased (2.0% vs 0.5%, approached significance)
Trust score:4/5

infectious disease episodes

1 evidences

In preschool children, zinc (alone or with iron) reduced episodes of illness and diarrhea but did not change growth or body composition over 12 months.

Trust comment: Randomized double-blind community trial with clear outcome data and appropriate design; moderate-to-high quality.

Study Details

PMID:8988907
Participants:219
Impact:−0.7 episodes (3.9 vs 4.6) compared with placebo
Trust score:4/5

diarrhea episodes

1 evidences

In preschool children, zinc (alone or with iron) reduced episodes of illness and diarrhea but did not change growth or body composition over 12 months.

Trust comment: Randomized double-blind community trial with clear outcome data and appropriate design; moderate-to-high quality.

Study Details

PMID:8988907
Participants:219
Impact:−0.4 episodes (0.7 vs 1.1) compared with placebo
Trust score:4/5

growth velocity and body composition

1 evidences

In preschool children, zinc (alone or with iron) reduced episodes of illness and diarrhea but did not change growth or body composition over 12 months.

Trust comment: Randomized double-blind community trial with clear outcome data and appropriate design; moderate-to-high quality.

Study Details

PMID:8988907
Participants:219
Impact:no change
Trust score:4/5

progressive sperm motility

1 evidences

Men receiving D-aspartic acid + ubiquinol + 10 mg zinc daily for 3 months showed improved progressive sperm motility and higher total testosterone versus placebo.

Trust comment: Randomized double-blind design but small group sizes and effects reported for a multi-ingredient regimen so attribution to zinc alone is limited.

Study Details

PMID:40248985
Participants:48
Impact:+43% (10.63 → 15.21; p=0.047)
Trust score:3/5

pregnancy rate

1 evidences

Randomized clinical observation: Jingling oral liquid increased pregnancy rates and improved semen parameters including higher seminal zinc and SOD.

Trust comment: Randomized but single-center trial with limited detail on blinding and methods; outcomes clinically relevant but study quality unclear.

Study Details

PMID:15074089
Participants:60
Impact:+36.6 percentage points (76.6% vs 40.0%; P<0.05)
Trust score:3/5

ZnT1 expression (leukocytes)

1 evidences

In obese young women, 30 mg/day zinc for 8 weeks increased leukocyte expression of zinc transporter genes ZnT1 and ZnT5.

Trust comment: Randomized intervention measuring molecular endpoints; small sample size limits generalizability but outcomes are directly measured.

Study Details

PMID:25240971
Participants:35
Impact:increased after supplementation
Trust score:4/5

ZnT5 expression (leukocytes)

1 evidences

In obese young women, 30 mg/day zinc for 8 weeks increased leukocyte expression of zinc transporter genes ZnT1 and ZnT5.

Trust comment: Randomized intervention measuring molecular endpoints; small sample size limits generalizability but outcomes are directly measured.

Study Details

PMID:25240971
Participants:35
Impact:increased after supplementation
Trust score:4/5

zinc intake (at 5–6 months)

1 evidences

In formula-fed infants, early versus later introduction of complementary foods did not affect serum zinc concentrations or zinc status at 12, 24, or 36 months.

Trust comment: Randomized prospective trial with completed follow-up in majority of participants and direct biochemical measures of zinc status.

Study Details

PMID:11320951
Participants:133
Impact:slightly lower in early group at 5 and 6 months (4.4 vs 4.8 mg/day at 5 months; 4.4 vs 4.7 mg/day at 6 months)
Trust score:4/5

duration of cold symptoms

2 evidences

Zinc nasal gel started within 24 hours of onset significantly shortened duration of common cold symptoms compared with placebo.

Trust comment: Double-blind placebo-controlled RCT with clear, large effect on symptom duration; well-designed though replication and safety considerations matter.

Study Details

PMID:11055098
Participants:213
Impact:−6.7 days (2.3 days zinc vs 9.0 days placebo)
Trust score:4/5

Zinc lozenges shortened the duration of common cold symptoms but caused more bad taste and nausea.

Trust comment: Randomized, double-blind, placebo-controlled RCT with objective median symptom durations but outcomes largely patient-reported; moderate sample size.

Study Details

PMID:8678384
Participants:100
Impact:median −3.2 days (4.4 vs 7.6 days)
Trust score:4/5

HbA1c (6 months)

1 evidences

In pre-diabetic adults given 30 mg/day zinc for 12 months, there was no significant effect on primary endpoints (HbA1c and fasting blood glucose) at 6 months; some secondary HOMA measures showed changes at later timepoints.

Trust comment: Randomized double-blind trial but prematurely halted with small sample (98) limiting power; primary endpoints were null.

Study Details

PMID:35451678
Participants:98
Impact:−0.02 (−0.14, 0.11) mean difference vs placebo — not significant
Trust score:3/5

fasting blood glucose (6 months)

1 evidences

In pre-diabetic adults given 30 mg/day zinc for 12 months, there was no significant effect on primary endpoints (HbA1c and fasting blood glucose) at 6 months; some secondary HOMA measures showed changes at later timepoints.

Trust comment: Randomized double-blind trial but prematurely halted with small sample (98) limiting power; primary endpoints were null.

Study Details

PMID:35451678
Participants:98
Impact:+0.17 mmol/L (−0.07, 0.42) mean difference vs placebo — not significant
Trust score:3/5

insulin sensitivity (12 months, HOMA %S)

1 evidences

In pre-diabetic adults given 30 mg/day zinc for 12 months, there was no significant effect on primary endpoints (HbA1c and fasting blood glucose) at 6 months; some secondary HOMA measures showed changes at later timepoints.

Trust comment: Randomized double-blind trial but prematurely halted with small sample (98) limiting power; primary endpoints were null.

Study Details

PMID:35451678
Participants:98
Impact:+12.17% (0.68, 23.65) vs placebo (secondary/timepoint-specific)
Trust score:3/5

disease control rate (Investigator's Global Assessment)

1 evidences

In patients with scalp psoriasis, a supramolecular active zinc antidandruff conditioner improved disease control at 4 weeks vs placebo and was similar to calcipotriol.

Trust comment: Multicentre randomized observed-blind noninferiority RCT (n=211) with clear clinical endpoint.

Study Details

PMID:37140426
Participants:211
Impact:39% experimental vs 25% placebo and 37% calcipotriol at week 4 (superior to placebo; noninferior to calcipotriol)
Trust score:4/5

nutritional status (biochemical and BIA measures)

1 evidences

In digestive-tract cancer patients on chemotherapy, oral selenium plus zinc prevented further worsening of nutritional parameters and reduced asthenia/increased appetite compared with no supplement.

Trust comment: Small randomized clinical trial combining selenium and zinc; limited sample and combined intervention confounds zinc-specific attribution.

Study Details

PMID:11360134
Participants:60
Impact:21/30 (70%) treated did not worsen vs 24/30 (80%) untreated showed significant decline over 60 days
Trust score:3/5

asthenia/appetite

1 evidences

In digestive-tract cancer patients on chemotherapy, oral selenium plus zinc prevented further worsening of nutritional parameters and reduced asthenia/increased appetite compared with no supplement.

Trust comment: Small randomized clinical trial combining selenium and zinc; limited sample and combined intervention confounds zinc-specific attribution.

Study Details

PMID:11360134
Participants:60
Impact:treated group had significant decrease in asthenia and increase in appetite
Trust score:3/5

incidence density of acute childhood diarrhoea

1 evidences

After 10 days of zinc treatment for acute diarrhoea, continuing zinc for 3 months reduced subsequent diarrhoea incidence compared with placebo but did not affect ARI or growth.

Trust comment: Randomized double-blind field trial with high follow-up rates (93–96%) and clear incidence outcomes in 353 children.

Study Details

PMID:20374562
Participants:353
Impact:reduced 28% during 3 months on supplementation (2.64 vs 3.66 episodes/person-year) and 21% over 9 months (2.05 vs 2.59 episodes/person-year)
Trust score:4/5

acute respiratory infections

1 evidences

After 10 days of zinc treatment for acute diarrhoea, continuing zinc for 3 months reduced subsequent diarrhoea incidence compared with placebo but did not affect ARI or growth.

Trust comment: Randomized double-blind field trial with high follow-up rates (93–96%) and clear incidence outcomes in 353 children.

Study Details

PMID:20374562
Participants:353
Impact:no effect
Trust score:4/5

growth

1 evidences

After 10 days of zinc treatment for acute diarrhoea, continuing zinc for 3 months reduced subsequent diarrhoea incidence compared with placebo but did not affect ARI or growth.

Trust comment: Randomized double-blind field trial with high follow-up rates (93–96%) and clear incidence outcomes in 353 children.

Study Details

PMID:20374562
Participants:353
Impact:no effect
Trust score:4/5

pneumonia incidence

3 evidences

Weekly oral zinc reduced pneumonia episodes and slightly reduced diarrhea incidence and reduced deaths in young children in this urban Bangladesh trial.

Trust comment: Large randomized trial with meaningful clinical endpoints and mortality benefit, though notable withdrawals may affect generalizability.

Study Details

PMID:16168782
Participants:1621
Impact:-17% (199 vs 286 incidents; RR 0.83; 95% CI 0.73–0.95)
Trust score:4/5

Among nursing-home residents, normal serum zinc was associated with lower pneumonia incidence, shorter illness duration, fewer antibiotic prescriptions, and lower mortality.

Trust comment: Observational analysis (n=578 baseline measures) nested within a trial; associations are plausible but not randomized for zinc status.

Study Details

PMID:17921398
Participants:578
Impact:decrease (normal vs low serum zinc associated with lower incidence)
Trust score:3/5

Daily zinc increased plasma zinc and reduced pneumonia incidence in young children but did not change overall acute lower respiratory tract infection rates.

Trust comment: Large double-blind randomized placebo-controlled trial with active surveillance and clear endpoints.

Study Details

PMID:12052800
Participants:2482
Impact:absolute risk reduction -2.5% (95% CI 0.4% to 4.6%); OR 0.74 after GEE
Trust score:5/5

acute lower respiratory tract infection incidence

1 evidences

Daily zinc increased plasma zinc and reduced pneumonia incidence in young children but did not change overall acute lower respiratory tract infection rates.

Trust comment: Large double-blind randomized placebo-controlled trial with active surveillance and clear endpoints.

Study Details

PMID:12052800
Participants:2482
Impact:no difference (absolute risk reduction -0.2%)
Trust score:5/5

birth head circumference

1 evidences

High-dose zinc in pregnancy increased newborn head circumference but did not significantly change birth weight or gestational age.

Trust comment: Double-blind randomized trial with clear outcomes but modest sample size (n=84) limits power for some endpoints.

Study Details

PMID:19658043
Participants:84
Impact:+1.3 cm (35.0 vs 33.7 cm; P < 0.05)
Trust score:4/5

Birth weight

6 evidences

Prenatal zinc supplementation produced a small increase in newborn length but had no effect on birth weight, neonatal morbidity, or mortality.

Trust comment: Large double‑blind randomized trial with high sample size and neonatal outcomes measured; effects are small and clinically modest.

Study Details

PMID:24220161
Participants:1956
Impact:no significant effect
Trust score:4/5

Maternal zinc supplementation (30 mg/d in last two trimesters) did not improve birth weight, gestational age, or other newborn anthropometric outcomes.

Trust comment: Double-blind, placebo-controlled trial with substantial enrollment and objective birth outcome measures, showing null effects.

Study Details

PMID:10617955
Participants:410
Impact:no significant change
Trust score:4/5

High-dose zinc in pregnancy increased newborn head circumference but did not significantly change birth weight or gestational age.

Trust comment: Double-blind randomized trial with clear outcomes but modest sample size (n=84) limits power for some endpoints.

Study Details

PMID:19658043
Participants:84
Impact:+141.6 g (2960.6 g vs 2819.0 g; not statistically significant)
Trust score:4/5

Randomized double-blind trial in pregnant women: micronutrient supplement raised maternal vitamin levels, was associated with 10% higher birth weights and fewer low-birth-weight infants; maternal plasma zinc correlated with newborn height.

Trust comment: Randomized double-blind placebo-controlled design but substantial attrition (100 recruited to 65 completed) limits certainty.

Study Details

PMID:14679367
Participants:65
Impact:+10% mean birth weight in supplemented group
Trust score:4/5

Adding 15 mg/day zinc from 16 weeks gestation to routine iron/folic acid did not improve birth weight or other measured pregnancy outcomes.

Trust comment: Large randomized controlled trial with clear null findings and adequate sample size.

Study Details

PMID:26365330
Participants:540
Impact:-10 g (3262 g vs 3272 g), no significant difference (p=0.780)
Trust score:4/5

Adding zinc to prenatal iron–folate supplements did not change pregnancy length or newborn size in this Peruvian cohort.

Trust comment: Large randomized prenatal trial with good follow-up and outcome ascertainment, showing null effects.

Study Details

PMID:10419991
Participants:1016
Impact:No difference (3267 g placebo vs 3300 g zinc; P>0.05)
Trust score:5/5

gestational age at delivery

1 evidences

High-dose zinc in pregnancy increased newborn head circumference but did not significantly change birth weight or gestational age.

Trust comment: Double-blind randomized trial with clear outcomes but modest sample size (n=84) limits power for some endpoints.

Study Details

PMID:19658043
Participants:84
Impact:+0.4 week (37.1 vs 36.7 weeks; not statistically significant)
Trust score:4/5

positive affect (mood)

1 evidences

Oral zinc supplementation (15 or 30 mg/day) did not change positive or negative affect in healthy older adults over 6 months.

Trust comment: Large, multi-center randomized placebo-controlled double-blind trial showing null effects on mood.

Study Details

PMID:21272413
Participants:387
Impact:no change versus placebo
Trust score:5/5

negative affect (mood)

1 evidences

Oral zinc supplementation (15 or 30 mg/day) did not change positive or negative affect in healthy older adults over 6 months.

Trust comment: Large, multi-center randomized placebo-controlled double-blind trial showing null effects on mood.

Study Details

PMID:21272413
Participants:387
Impact:no change versus placebo
Trust score:5/5

menstrual pain severity (VAS)

1 evidences

Short-course zinc sulfate taken at menses reduced menstrual pain severity over multiple cycles and decreased the proportion reporting academic impact.

Trust comment: Double-blind randomized trial with adequate sample for effect on pain but some methodological limitations (compliance observation, statistical planning).

Study Details

PMID:37165643
Participants:100
Impact:decreased from 5.28 baseline to 2.56 (month2) and 1.95 (month3); difference vs placebo -1.24 (month2) and -2.00 (month3)
Trust score:4/5

use of additional analgesics

1 evidences

Short-course zinc sulfate taken at menses reduced menstrual pain severity over multiple cycles and decreased the proportion reporting academic impact.

Trust comment: Double-blind randomized trial with adequate sample for effect on pain but some methodological limitations (compliance observation, statistical planning).

Study Details

PMID:37165643
Participants:100
Impact:no significant difference vs placebo
Trust score:4/5

nausea/vomiting (adverse events)

1 evidences

Short-course zinc sulfate taken at menses reduced menstrual pain severity over multiple cycles and decreased the proportion reporting academic impact.

Trust comment: Double-blind randomized trial with adequate sample for effect on pain but some methodological limitations (compliance observation, statistical planning).

Study Details

PMID:37165643
Participants:100
Impact:6% (zinc) vs 2% (placebo); not statistically significant
Trust score:4/5

wound healing (rate/extent)

1 evidences

Topical regular crystalline insulin (contains zinc) and aqueous zinc chloride both improved uncomplicated cutaneous wound healing compared with saline control.

Trust comment: Randomized pilot study showing benefit but limited by pilot design and incomplete reporting of some methods.

Study Details

PMID:24393153
Participants:90
Impact:enhanced vs saline control (reported p≈0.004)
Trust score:3/5

body site effect (upper vs lower)

1 evidences

Topical regular crystalline insulin (contains zinc) and aqueous zinc chloride both improved uncomplicated cutaneous wound healing compared with saline control.

Trust comment: Randomized pilot study showing benefit but limited by pilot design and incomplete reporting of some methods.

Study Details

PMID:24393153
Participants:90
Impact:greater improvement in upper body wounds than lower body (reported p≈0.015)
Trust score:3/5

Fatigue score

1 evidences

Zinc (70 mg/day elemental) prevented worsening of fatigue and preserved quality of life during early chemotherapy after colorectal cancer surgery; plasma zinc rose.

Trust comment: Randomized double-blind trial with clear outcomes but very small completed sample (n=24), limiting generalizability.

Study Details

PMID:28444084
Participants:24
Impact:No change in Zinc group (~40 points) vs decrease in Placebo from 43 to 36 (−7 points, p=0.02) indicating worsening in placebo
Trust score:3/5

quality of life score

1 evidences

Zinc (70 mg/day elemental) prevented worsening of fatigue and preserved quality of life during early chemotherapy after colorectal cancer surgery; plasma zinc rose.

Trust comment: Randomized double-blind trial with clear outcomes but very small completed sample (n=24), limiting generalizability.

Study Details

PMID:28444084
Participants:24
Impact:Zinc group stable (121→123); Placebo worsened 126→116 (−10 points, p=0.02)
Trust score:3/5

Effect in well children

1 evidences

Reducing dietary phytate (corn-soy diet) increased zinc absorption in children recovering from tuberculosis but had no effect in well children.

Trust comment: Human stable-isotope study with objective absorption measures but very small short-term sample (n=23), limiting external validity.

Study Details

PMID:11110854
Participants:23
Impact:No significant change in fractional or total zinc absorption (no effect)
Trust score:3/5

Perceptible taste threshold (filter-paper method)

1 evidences

Polaprezinc (zinc agent) improved measurable taste thresholds versus placebo at 8 weeks; overall responder-rate difference was not significant except in a predefined subgroup (non-depressed with complete taste impairment).

Trust comment: Large randomized double-blind placebo-controlled trial with objective taste testing, but primary overall responder endpoint showed mixed significance and effects depended on subgroup selection.

Study Details

PMID:23484369
Participants:219
Impact:Statistically significant improvement in zinc-treated arm vs placebo at 8 weeks (measured threshold scores)
Trust score:4/5

Overall responder rate

1 evidences

Polaprezinc (zinc agent) improved measurable taste thresholds versus placebo at 8 weeks; overall responder-rate difference was not significant except in a predefined subgroup (non-depressed with complete taste impairment).

Trust comment: Large randomized double-blind placebo-controlled trial with objective taste testing, but primary overall responder endpoint showed mixed significance and effects depended on subgroup selection.

Study Details

PMID:23484369
Participants:219
Impact:Treatment 55.6% vs Placebo 43.2% (difference not statistically significant)
Trust score:4/5

Responder rate in non-depressed with complete taste impairment

1 evidences

Polaprezinc (zinc agent) improved measurable taste thresholds versus placebo at 8 weeks; overall responder-rate difference was not significant except in a predefined subgroup (non-depressed with complete taste impairment).

Trust comment: Large randomized double-blind placebo-controlled trial with objective taste testing, but primary overall responder endpoint showed mixed significance and effects depended on subgroup selection.

Study Details

PMID:23484369
Participants:219
Impact:Treatment 60.9% vs Placebo 39.5% (statistically significant in this subgroup)
Trust score:4/5

Plasma zinc status (improvement to ≥70 µg/dL)

1 evidences

Six-month consumption of marginally higher-zinc biofortified wheat did not produce meaningful differences in plasma zinc status vs low-zinc wheat, but was associated with reduced days with pneumonia and vomiting in children and reduced days with fever in women.

Trust comment: Very large randomized double-masked trial with high compliance; validity limited by a smaller-than-planned zinc differential between intervention and control wheat batches.

Study Details

PMID:30219062
Participants:6005
Impact:No difference between groups (children improved 27.2% vs 26.7%; mean diff in change +1.08 µg/dL, 95% CI −0.54 to 2.69)
Trust score:4/5

Days with pneumonia (children)

1 evidences

Six-month consumption of marginally higher-zinc biofortified wheat did not produce meaningful differences in plasma zinc status vs low-zinc wheat, but was associated with reduced days with pneumonia and vomiting in children and reduced days with fever in women.

Trust comment: Very large randomized double-masked trial with high compliance; validity limited by a smaller-than-planned zinc differential between intervention and control wheat batches.

Study Details

PMID:30219062
Participants:6005
Impact:−18% days with pneumonia (RR 0.82, 95% CI 0.68–0.99)
Trust score:4/5

Days with vomiting (children)

1 evidences

Six-month consumption of marginally higher-zinc biofortified wheat did not produce meaningful differences in plasma zinc status vs low-zinc wheat, but was associated with reduced days with pneumonia and vomiting in children and reduced days with fever in women.

Trust comment: Very large randomized double-masked trial with high compliance; validity limited by a smaller-than-planned zinc differential between intervention and control wheat batches.

Study Details

PMID:30219062
Participants:6005
Impact:−40% days with vomiting (RR 0.60, 95% CI 0.44–0.83)
Trust score:4/5

Full zinc adherence

1 evidences

Phone-call reminders (days 3 and 7) increased caregivers' adherence to zinc therapy and combined ORS+zinc adherence for pediatric acute diarrhea compared with standard care.

Trust comment: Randomized trial with high completion and objective diary-based adherence measures; single-center and open-label design are limitations.

Study Details

PMID:39242528
Participants:364
Impact:Intervention 72.1% vs Control 60.8% (OR 1.67, p=0.022); mean zinc adherence score +7.3% (MD 7.3, 95% CI 3.74–10.86, p<0.001)
Trust score:4/5

Full ORS adherence

1 evidences

Phone-call reminders (days 3 and 7) increased caregivers' adherence to zinc therapy and combined ORS+zinc adherence for pediatric acute diarrhea compared with standard care.

Trust comment: Randomized trial with high completion and objective diary-based adherence measures; single-center and open-label design are limitations.

Study Details

PMID:39242528
Participants:364
Impact:Intervention 82.5% vs Control 75.1% (OR 1.56, p=0.085); mean ORS adherence score +4.1% (MD 4.1, 95% CI 0.60–7.60, p=0.020)
Trust score:4/5

Full combined adherence (ORS+zinc)

1 evidences

Phone-call reminders (days 3 and 7) increased caregivers' adherence to zinc therapy and combined ORS+zinc adherence for pediatric acute diarrhea compared with standard care.

Trust comment: Randomized trial with high completion and objective diary-based adherence measures; single-center and open-label design are limitations.

Study Details

PMID:39242528
Participants:364
Impact:Intervention 58.5% vs Control 43.6% (OR 1.82, p=0.005); mean combined score +5.7% (MD 5.7, 95% CI 3.23–8.17, p<0.001)
Trust score:4/5

Serum and hair zinc concentrations

1 evidences

Providing red meat or fortified toddler milk raised dietary zinc intake modestly (~+0.7–0.8 mg/day) but did not change serum or hair zinc concentrations in toddlers over 20 weeks.

Trust comment: Randomized 20-week intervention with biomarker measurement and adequate sample size; dietary increases were small and did not translate to biochemical change.

Study Details

PMID:20980643
Participants:225
Impact:No corresponding increase in serum or hair zinc concentrations (no change in biochemical zinc status)
Trust score:4/5

superoxide dismutase activity

2 evidences

Graves' disease patients treated with methimazole were given antioxidant supplements (no zinc in the supplement) and erythrocyte SOD, Cu, Zn and total antioxidant status were followed for 60 days.

Trust comment: Controlled study on humans with moderate sample size; zinc was measured but not supplemented, and exact numeric changes for zinc are not provided in the text.

Study Details

PMID:15899653
Participants:55
Impact:decreased significantly in both groups; no between-group difference
Trust score:3/5

Small randomized trial in colorectal cancer patients; zinc raised SOD, lowered GPx at one timepoint, and preserved vitamin E but did not change lipid-peroxidation markers.

Trust comment: Randomized placebo-controlled trial but small sample (n=24) and heterogeneous chemo regimens limit generalizability.

Study Details

PMID:26066525
Participants:24
Impact:increased (higher vs placebo before chemo cycles 1, 2, and 4)
Trust score:3/5

Glutathione peroxidase activity

1 evidences

Small randomized trial in colorectal cancer patients; zinc raised SOD, lowered GPx at one timepoint, and preserved vitamin E but did not change lipid-peroxidation markers.

Trust comment: Randomized placebo-controlled trial but small sample (n=24) and heterogeneous chemo regimens limit generalizability.

Study Details

PMID:26066525
Participants:24
Impact:decreased (lower vs placebo before cycle 3)
Trust score:3/5

vitamin E concentration

2 evidences

Small randomized trial in colorectal cancer patients; zinc raised SOD, lowered GPx at one timepoint, and preserved vitamin E but did not change lipid-peroxidation markers.

Trust comment: Randomized placebo-controlled trial but small sample (n=24) and heterogeneous chemo regimens limit generalizability.

Study Details

PMID:26066525
Participants:24
Impact:maintained with zinc vs decrease in placebo
Trust score:3/5

In burned children, combined vitamin C+E+zinc lowered lipid peroxidation and sped wound healing compared with placebo.

Trust comment: Randomized double-blind pilot RCT but small sample size and zinc was given as part of a combined antioxidant mixture, so zinc-specific effects are not isolated.

Study Details

PMID:19692922
Participants:32
Impact:Increased (P = 0.016)
Trust score:3/5

height gain (overall)

1 evidences

14-month double-blind trial in preschool children showed modest growth benefit in boys (about +0.9 cm) with zinc supplementation; overall effects small.

Trust comment: Long duration, double-blind randomized design and adequate sample for subgroup findings, though overall effects were small and sex-specific.

Study Details

PMID:9394693
Participants:98
Impact:mean +0.5 cm over 14 months (P = 0.10, not statistically significant)
Trust score:4/5

height gain (boys)

1 evidences

14-month double-blind trial in preschool children showed modest growth benefit in boys (about +0.9 cm) with zinc supplementation; overall effects small.

Trust comment: Long duration, double-blind randomized design and adequate sample for subgroup findings, though overall effects were small and sex-specific.

Study Details

PMID:9394693
Participants:98
Impact:mean +0.9 cm vs placebo (P = 0.045)
Trust score:4/5

median serum zinc concentration

1 evidences

Cross-sectional analysis found a high prevalence (31.3%) of biochemical zinc deficiency in healthy 1–3-year-old children in Western Europe.

Trust comment: Relatively large, multicenter sample with standardized assays, though cross-sectional design limits causal inference.

Study Details

PMID:34835970
Participants:278
Impact:median 11.0 µmol/L (IQR 9.0–12.2)
Trust score:4/5

Serum BDNF

1 evidences

Overweight/obese adults given 30 mg zinc daily for 12 weeks had higher blood zinc and BDNF and felt less depressed than those on placebo.

Trust comment: Randomized double-blind placebo-controlled trial with modest sample (46 completers); clear biochemical and clinical signal but relatively small N.

Study Details

PMID:24621065
Participants:46
Impact:increased
Trust score:4/5

Depressive symptoms (BDI-II)

1 evidences

Overweight/obese adults given 30 mg zinc daily for 12 weeks had higher blood zinc and BDNF and felt less depressed than those on placebo.

Trust comment: Randomized double-blind placebo-controlled trial with modest sample (46 completers); clear biochemical and clinical signal but relatively small N.

Study Details

PMID:24621065
Participants:46
Impact:decreased (greater reduction vs placebo; effect in BDI≥10 subgroup)
Trust score:4/5

cognitive development

1 evidences

Children whose mothers received prenatal zinc did not differ at 4.5 years in cognitive, language, social or behavioral tests compared with controls.

Trust comment: Follow-up of a prenatal supplementation trial with good retention (184 children); well-conducted assessments showing null effects at 54 months.

Study Details

PMID:20484451
Participants:184
Impact:no difference
Trust score:4/5

Language and number skills

1 evidences

Children whose mothers received prenatal zinc did not differ at 4.5 years in cognitive, language, social or behavioral tests compared with controls.

Trust comment: Follow-up of a prenatal supplementation trial with good retention (184 children); well-conducted assessments showing null effects at 54 months.

Study Details

PMID:20484451
Participants:184
Impact:no difference
Trust score:4/5

Behavioral adjustment / social development

1 evidences

Children whose mothers received prenatal zinc did not differ at 4.5 years in cognitive, language, social or behavioral tests compared with controls.

Trust comment: Follow-up of a prenatal supplementation trial with good retention (184 children); well-conducted assessments showing null effects at 54 months.

Study Details

PMID:20484451
Participants:184
Impact:no difference
Trust score:4/5

Anger-hostility (POMS)

1 evidences

Young women given multivitamin plus 7 mg zinc daily for 10 weeks showed reduced anger and depression scores and higher serum zinc versus multivitamin alone.

Trust comment: Small randomized double-blind pilot (n=30) with positive mood and serum zinc changes but limited sample size for broad generalization.

Study Details

PMID:20087376
Participants:30
Impact:decreased
Trust score:3/5

Depression-dejection (POMS)

1 evidences

Young women given multivitamin plus 7 mg zinc daily for 10 weeks showed reduced anger and depression scores and higher serum zinc versus multivitamin alone.

Trust comment: Small randomized double-blind pilot (n=30) with positive mood and serum zinc changes but limited sample size for broad generalization.

Study Details

PMID:20087376
Participants:30
Impact:decreased
Trust score:3/5

Fractional zinc absorption (FZA)

2 evidences

In 60 children, NaFeEDTA- or FeSO4-fortified soy sauce did not change fractional zinc absorption or total zinc absorption compared with non-fortified soy sauce.

Trust comment: Randomized human study with modest sample (n=60) and direct measurement of zinc absorption; limited by small size.

Study Details

PMID:25582850
Participants:60
Impact:no significant difference among NaFeEDTA, FeSO4, and control groups (P=0.3895)
Trust score:3/5

In a randomized crossover isotope study, zinc-biofortified potatoes provided ~22.5% more total absorbed zinc per meal than regular potatoes despite a lower fractional absorption.

Trust comment: Rigorous randomized crossover design using stable isotopes and careful controls; high internal validity though limited to adult women in one region.

Study Details

PMID:37648112
Participants:37
Impact:biofortified 20.8% vs regular 25.5% (↓ FZA for biofortified)
Trust score:5/5

Incidence of upper respiratory tract infection (URTI)

1 evidences

Daily 5 mg zinc for 12 months in infants (6–12 mo start) reduced episodes of upper respiratory infections and acute diarrhoea versus no supplement.

Trust comment: Large triple-blind randomized controlled trial (n=355) with clear, significant reductions in URTI and diarrhoea incidence.

Study Details

PMID:27255474
Participants:355
Impact:decreased (control vs zinc IRR 1.73; zinc associated with ~42% lower incidence)
Trust score:5/5

Incidence of acute diarrhoeal disease

1 evidences

Daily 5 mg zinc for 12 months in infants (6–12 mo start) reduced episodes of upper respiratory infections and acute diarrhoea versus no supplement.

Trust comment: Large triple-blind randomized controlled trial (n=355) with clear, significant reductions in URTI and diarrhoea incidence.

Study Details

PMID:27255474
Participants:355
Impact:decreased (control vs zinc IRR 1.43; zinc associated with ~30% lower incidence)
Trust score:5/5

Oxidative stress markers (TBARS, protein thiols, glutathione, FRAP)

1 evidences

In healthy middle-aged and older adults, 15–30 mg/day zinc for 6 months did not change oxidative stress markers, though Cu/Zn SOD activity increased.

Trust comment: Large multicenter randomized placebo-controlled study (n=387) with comprehensive assays showing largely null antioxidant effects aside from SOD activity.

Study Details

PMID:18978165
Participants:387
Impact:no change
Trust score:5/5

Cu/Zn superoxide dismutase activity

1 evidences

In healthy middle-aged and older adults, 15–30 mg/day zinc for 6 months did not change oxidative stress markers, though Cu/Zn SOD activity increased.

Trust comment: Large multicenter randomized placebo-controlled study (n=387) with comprehensive assays showing largely null antioxidant effects aside from SOD activity.

Study Details

PMID:18978165
Participants:387
Impact:increased
Trust score:5/5

linear growth (length) — stunted infants

1 evidences

Daily zinc improved growth, weight and reduced infections in supplemented stunted infants over 6 months.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear clinically important outcomes and significant p-values.

Study Details

PMID:10885352
Participants:100
Impact:+7.0 cm (zinc) vs +2.8 cm (placebo) over 6 months
Trust score:5/5

infectious morbidity / anorexia incidence

1 evidences

Daily zinc improved growth, weight and reduced infections in supplemented stunted infants over 6 months.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear clinically important outcomes and significant p-values.

Study Details

PMID:10885352
Participants:100
Impact:total morbidity events per child 1.56 (stunted zinc) vs 3.38 (stunted placebo); anorexia incidence markedly lower with zinc
Trust score:5/5

insulin-like growth factor I (IGF-1)

1 evidences

Six weeks of zinc raised serum zinc but did not change IGF-1 or bone turnover markers in peripubertal girls.

Trust comment: Small randomized trial with short duration and limited outcome changes; increases confidence in zinc absorption but limited clinical effect data.

Study Details

PMID:10465179
Participants:47
Impact:no change
Trust score:3/5

biochemical markers of bone turnover

1 evidences

Six weeks of zinc raised serum zinc but did not change IGF-1 or bone turnover markers in peripubertal girls.

Trust comment: Small randomized trial with short duration and limited outcome changes; increases confidence in zinc absorption but limited clinical effect data.

Study Details

PMID:10465179
Participants:47
Impact:no change
Trust score:3/5

zinc Cmax

1 evidences

Single-dose crossover PK study in healthy males found the new iron+zinc tablet bioequivalent to reference for zinc metrics.

Trust comment: Well-designed randomized crossover PK study in healthy volunteers with standard bioequivalence analysis; small sample but appropriate for PK endpoints.

Study Details

PMID:10205637
Participants:30
Impact:no significant difference between formulations (bioequivalent)
Trust score:4/5

zinc AUC0-24

1 evidences

Single-dose crossover PK study in healthy males found the new iron+zinc tablet bioequivalent to reference for zinc metrics.

Trust comment: Well-designed randomized crossover PK study in healthy volunteers with standard bioequivalence analysis; small sample but appropriate for PK endpoints.

Study Details

PMID:10205637
Participants:30
Impact:no significant difference between formulations (bioequivalent)
Trust score:4/5

iron–zinc interaction

1 evidences

Single-dose crossover PK study in healthy males found the new iron+zinc tablet bioequivalent to reference for zinc metrics.

Trust comment: Well-designed randomized crossover PK study in healthy volunteers with standard bioequivalence analysis; small sample but appropriate for PK endpoints.

Study Details

PMID:10205637
Participants:30
Impact:possible inhibition of zinc absorption by iron content (not quantified)
Trust score:4/5

parent-rated attention deficit prevalence

1 evidences

Ten weeks of 15 mg/day zinc syrup reduced parent-rated prevalence of attention deficit and hyperactivity in low-income primary-school children, with no change in teacher ratings.

Trust comment: Double-blind randomized placebo-controlled trial with adequate sample and consistent parental-reported effects; teacher reports did not corroborate.

Study Details

PMID:19133873
Participants:218
Impact:decreased (p = 0.01) in zinc group
Trust score:4/5

parent-rated hyperactivity prevalence

1 evidences

Ten weeks of 15 mg/day zinc syrup reduced parent-rated prevalence of attention deficit and hyperactivity in low-income primary-school children, with no change in teacher ratings.

Trust comment: Double-blind randomized placebo-controlled trial with adequate sample and consistent parental-reported effects; teacher reports did not corroborate.

Study Details

PMID:19133873
Participants:218
Impact:decreased (p = 0.004) in zinc group
Trust score:4/5

teacher-rated behaviour scores

1 evidences

Ten weeks of 15 mg/day zinc syrup reduced parent-rated prevalence of attention deficit and hyperactivity in low-income primary-school children, with no change in teacher ratings.

Trust comment: Double-blind randomized placebo-controlled trial with adequate sample and consistent parental-reported effects; teacher reports did not corroborate.

Study Details

PMID:19133873
Participants:218
Impact:no change
Trust score:4/5

tryptophan pathway — indoleacetate

1 evidences

Daily 5 mg zinc induced limited changes in infant blood metabolome (several metabolites in amino acid, lipid, nucleotide pathways), while age drove larger changes.

Trust comment: Randomized placebo-controlled infant trial with metabolomics; small sample and limited magnitude of zinc-associated changes relative to age effects.

Study Details

PMID:38092153
Participants:50
Impact:altered with zinc supplementation (direction not specified)
Trust score:4/5

fatty acid metabolites (eicosanedioate, 2-aminooctanoate)

1 evidences

Daily 5 mg zinc induced limited changes in infant blood metabolome (several metabolites in amino acid, lipid, nucleotide pathways), while age drove larger changes.

Trust comment: Randomized placebo-controlled infant trial with metabolomics; small sample and limited magnitude of zinc-associated changes relative to age effects.

Study Details

PMID:38092153
Participants:50
Impact:altered with zinc supplementation (direction not specified)
Trust score:4/5

purine metabolism — N6-succinyladenosine

1 evidences

Daily 5 mg zinc induced limited changes in infant blood metabolome (several metabolites in amino acid, lipid, nucleotide pathways), while age drove larger changes.

Trust comment: Randomized placebo-controlled infant trial with metabolomics; small sample and limited magnitude of zinc-associated changes relative to age effects.

Study Details

PMID:38092153
Participants:50
Impact:altered with zinc supplementation (direction not specified)
Trust score:4/5

proportion without diarrhoea on day 2

1 evidences

ORS with added L. reuteri and zinc showed trends toward faster recovery but did not significantly outperform ORS alone in well-nourished non-hospitalized infants with mild acute diarrhoea.

Trust comment: Randomized double-blind placebo-controlled trial but likely underpowered; well-conducted with objective severity measures.

Study Details

PMID:30200394
Participants:51
Impact:no significant difference: 64.3% (ORS+Lr&Z) vs 56.5% (ORS alone), p = 0.8
Trust score:4/5

diarrhoea severity (day 2 and 6)

1 evidences

ORS with added L. reuteri and zinc showed trends toward faster recovery but did not significantly outperform ORS alone in well-nourished non-hospitalized infants with mild acute diarrhoea.

Trust comment: Randomized double-blind placebo-controlled trial but likely underpowered; well-conducted with objective severity measures.

Study Details

PMID:30200394
Participants:51
Impact:both groups improved; supplemented group trended better but differences not statistically significant
Trust score:4/5

Safety/tolerability

1 evidences

ORS with added L. reuteri and zinc showed trends toward faster recovery but did not significantly outperform ORS alone in well-nourished non-hospitalized infants with mild acute diarrhoea.

Trust comment: Randomized double-blind placebo-controlled trial but likely underpowered; well-conducted with objective severity measures.

Study Details

PMID:30200394
Participants:51
Impact:well tolerated with no adverse effects reported
Trust score:4/5

HOMA-IR (insulin resistance)

3 evidences

In overweight/obese NAFLD patients on a calorie-restriction diet, 30 mg/day zinc for 12 weeks improved insulin resistance and oxidative stress markers but did not improve lipid profile beyond diet.

Trust comment: Randomized, double-blind, placebo-controlled trial with moderate sample size and clear outcomes supports moderate-high trust.

Study Details

PMID:32932174
Participants:56
Impact:improved (decreased) with zinc vs placebo
Trust score:4/5

Three months of combined myo-inositol and zinc (with GOS) did not improve HOMA-IR overall but modestly improved HDL and showed reduced fasting insulin and HOMA-IR in a severe-obesity subgroup.

Trust comment: Randomized double-blind trial but small sample, short duration, and zinc was combined with myo-inositol (attribution to zinc alone unclear).

Study Details

PMID:39781581
Participants:50
Impact:no significant change overall after 3 months
Trust score:3/5

Eight weeks of daily zinc (20 mg) in obese prepubertal children reduced fasting glucose, insulin and insulin resistance.

Trust comment: Triple-masked randomized placebo-controlled crossover trial with objective metabolic measures but modest sample size.

Study Details

PMID:20045801
Participants:60
Impact:↓ (significant) after zinc
Trust score:4/5

serum superoxide dismutase (SOD1)

1 evidences

In overweight/obese NAFLD patients on a calorie-restriction diet, 30 mg/day zinc for 12 weeks improved insulin resistance and oxidative stress markers but did not improve lipid profile beyond diet.

Trust comment: Randomized, double-blind, placebo-controlled trial with moderate sample size and clear outcomes supports moderate-high trust.

Study Details

PMID:32932174
Participants:56
Impact:increased with zinc vs placebo
Trust score:4/5

malondialdehyde (MDA)

3 evidences

In overweight/obese NAFLD patients on a calorie-restriction diet, 30 mg/day zinc for 12 weeks improved insulin resistance and oxidative stress markers but did not improve lipid profile beyond diet.

Trust comment: Randomized, double-blind, placebo-controlled trial with moderate sample size and clear outcomes supports moderate-high trust.

Study Details

PMID:32932174
Participants:56
Impact:decreased with zinc vs placebo
Trust score:4/5

Twelve weeks of magnesium-zinc-calcium-vitamin D co-supplementation in women with PCOS reduced hirsutism and some inflammation/oxidative stress markers and increased antioxidant capacity.

Trust comment: Randomized double-blind placebo-controlled trial with clear biomarker changes, but co-supplementation prevents attribution of effects solely to zinc.

Study Details

PMID:28668998
Participants:60
Impact:-0.4 ± 0.3 µmol/L vs +0.2 ± 1.0 µmol/L (change)
Trust score:4/5

In pregnant women at risk for IUGR, 30 mg/day zinc for 10 weeks reduced inflammation and oxidative stress markers and lowered insulin; no effect on uterine artery PI.

Trust comment: Randomized double-blind placebo-controlled trial with biomarker endpoints but small sample (n=52) limits generalizability.

Study Details

PMID:31248307
Participants:52
Impact:-0.23 µmol/L (β)
Trust score:4/5

lipid profile (TC, LDL-c, TG)

1 evidences

In overweight/obese NAFLD patients on a calorie-restriction diet, 30 mg/day zinc for 12 weeks improved insulin resistance and oxidative stress markers but did not improve lipid profile beyond diet.

Trust comment: Randomized, double-blind, placebo-controlled trial with moderate sample size and clear outcomes supports moderate-high trust.

Study Details

PMID:32932174
Participants:56
Impact:no beneficial change beyond weight-loss diet
Trust score:4/5

antioxidant status (TAC, GSH, SOD)

1 evidences

Zinc (100 mg/day) for 2 months increased blood zinc and antioxidant markers and reduced lipid peroxidation in hemodialysis patients.

Trust comment: Double-blind randomized crossover RCT in 65 HD patients with clear biochemical endpoints and significant p-values.

Study Details

PMID:23140661
Participants:65
Impact:↑ significant increase (P < .001 to P = .003)
Trust score:4/5

hair zinc level

1 evidences

In children with atopic dermatitis and low hair zinc, oral zinc raised hair zinc and improved eczema severity, skin barrier function, and itch.

Trust comment: Moderate-quality interventional study in 58 patients; randomization/allocation details unclear and sample modest.

Study Details

PMID:24473704
Participants:58
Impact:↑ significant increase (p < 0.001)
Trust score:3/5

eczema severity (EASI)

1 evidences

In children with atopic dermatitis and low hair zinc, oral zinc raised hair zinc and improved eczema severity, skin barrier function, and itch.

Trust comment: Moderate-quality interventional study in 58 patients; randomization/allocation details unclear and sample modest.

Study Details

PMID:24473704
Participants:58
Impact:↓ significant improvement (p = 0.044)
Trust score:3/5

pruritus (itch)

1 evidences

In children with atopic dermatitis and low hair zinc, oral zinc raised hair zinc and improved eczema severity, skin barrier function, and itch.

Trust comment: Moderate-quality interventional study in 58 patients; randomization/allocation details unclear and sample modest.

Study Details

PMID:24473704
Participants:58
Impact:↓ significant improvement (p < 0.001)
Trust score:3/5

time to walking unassisted

1 evidences

Daily supplements (iron/folic acid ± zinc) shortened time to unassisted walking and improved hemoglobin and zinc protoporphyrin in at-risk infants.

Trust comment: Large community-based double-blind RCT (n=354) with clinically meaningful motor and hematologic endpoints.

Study Details

PMID:16920865
Participants:354
Impact:↓ median ~15 days faster with iron (P = 0.035; RR = 1.28); ~30 days faster if baseline IDA (P = 0.002; RR = 1.68)
Trust score:5/5

hemoglobin (Hb)

2 evidences

Daily supplements (iron/folic acid ± zinc) shortened time to unassisted walking and improved hemoglobin and zinc protoporphyrin in at-risk infants.

Trust comment: Large community-based double-blind RCT (n=354) with clinically meaningful motor and hematologic endpoints.

Study Details

PMID:16920865
Participants:354
Impact:↑ improved with FeFA and with Zn alone (vs placebo)
Trust score:5/5

Fortified porridge improved anemia, iron and selenium status in Zambian infants but did not significantly raise overall serum zinc.

Trust comment: Large double-blind randomized trial (n=743) with objective biochemical endpoints; limited efficacy on overall zinc status.

Study Details

PMID:21411608
Participants:743
Impact:increase (overall treatment effect, P=0.001)
Trust score:4/5

zinc protoporphyrin (ZPP)

1 evidences

Daily supplements (iron/folic acid ± zinc) shortened time to unassisted walking and improved hemoglobin and zinc protoporphyrin in at-risk infants.

Trust comment: Large community-based double-blind RCT (n=354) with clinically meaningful motor and hematologic endpoints.

Study Details

PMID:16920865
Participants:354
Impact:↓ improved with FeFA and with Zn alone (vs placebo)
Trust score:5/5

Prevalence of zinc deficiency

5 evidences

Six months of zinc‑fortified rice increased serum zinc, lowered zinc deficiency prevalence, and (for NutriRice) increased serum folate in Cambodian schoolchildren.

Trust comment: Large double-blind cluster-RCT with biochemical outcomes and appropriate statistical methods; high external validity for similar settings.

Study Details

PMID:31756911
Participants:1667
Impact:reduced (endline odds ratios vs placebo: URO ~0.25, NutriRice ~0.16)
Trust score:5/5

Cluster RCT sub-study in infants aged 6–12 months: 4 months of daily supplementation (MNP, syrup, or fortified food) increased serum zinc in all groups, with syrup showing the largest increase; MNP reduced anemia prevalence.

Trust comment: Large cluster-randomized trial with biochemical endpoints and high compliance in subgroups, providing strong evidence for zinc status improvement.

Study Details

PMID:35684031
Participants:283
Impact:Decreased in all groups, largest reduction with syrup
Trust score:5/5

Ten-week zinc- and micronutrient-rich food or ayurvedic zinc supplements increased plasma zinc and reduced zinc deficiency prevalence in adolescent girls.

Trust comment: Randomized 10-week intervention in 180 girls with biochemical outcome measures and reported percentage changes.

Study Details

PMID:22129855
Participants:180
Impact:↓ food: 73% → 53.1%; ayurvedic zinc: 73.7% → 36.2%
Trust score:4/5

Between 2002 and 2012 zinc status in rural Chinese schoolchildren improved markedly (higher serum zinc, lower prevalence of deficiency and stunting).

Trust comment: Large, population-based survey using established WHO/UNICEF/IAEA/IZiNCG indicators across two time points, providing robust observational trends.

Study Details

PMID:28101714
Participants:3407
Impact:decrease from 44.4% (2002) to 10.4% (2012)
Trust score:4/5

A 22-week school-based multiple micronutrient supplement (including zinc 10 mg/day) increased plasma zinc and reduced zinc deficiency prevalence in 6–9-year-old children.

Trust comment: Large, well-conducted cluster-randomised, double-blind trial with high retention and appropriate biochemical corrections; findings for zinc are direct and significant.

Study Details

PMID:33580103
Participants:347
Impact:-17.3 percentage points (intervention effect, 95% CI −34.4, −0.2)
Trust score:5/5

plasma retinol / vitamin A status

1 evidences

Ten-week zinc- and micronutrient-rich food or ayurvedic zinc supplements increased plasma zinc and reduced zinc deficiency prevalence in adolescent girls.

Trust comment: Randomized 10-week intervention in 180 girls with biochemical outcome measures and reported percentage changes.

Study Details

PMID:22129855
Participants:180
Impact:↑ 38.2% with ayurvedic zinc; food supplement also improved β‑carotene (↑56.2%)
Trust score:4/5

bone mineral content (BMC)

1 evidences

Children with growth hormone deficiency receiving calcium + vitamin D (with or without zinc) had large increases in bone mineral content and bone area over one year.

Trust comment: Pilot randomized trial with small sample (n=31); suggests benefit but limited power and generalizability.

Study Details

PMID:23224626
Participants:31
Impact:↑ greater % increase in zinc group: 51% vs 49% (p < 0.05)
Trust score:3/5

bone area (BA)

1 evidences

Children with growth hormone deficiency receiving calcium + vitamin D (with or without zinc) had large increases in bone mineral content and bone area over one year.

Trust comment: Pilot randomized trial with small sample (n=31); suggests benefit but limited power and generalizability.

Study Details

PMID:23224626
Participants:31
Impact:↑ greater % increase in zinc group: 36% vs 34% (p < 0.05)
Trust score:3/5

mental development index (Bayley)

1 evidences

Daily zinc (5 mg) for 5 months was associated with slightly lower mental development scores in a subsample of Bangladeshi infants.

Trust comment: Double-blind randomized controlled trial with a well-defined developmental subsample (n=212); unexpected small negative effect noted.

Study Details

PMID:11522564
Participants:212
Impact:↓ slightly lower scores in zinc group (beta = 3.7, SE = 1.3, P < 0.005)
Trust score:4/5

hematocrit

2 evidences

Infants counseled to eat red meat more frequently from 6–12 months had higher meat intake and improved haemoglobin/hematocrit but no change in zinc status or linear growth at 12 months.

Trust comment: Randomized trial with biochemical measures but small sample (76 completers) and short follow-up limit generalizability.

Study Details

PMID:23945724
Participants:76
Impact:+1.04% change vs −0.15%; P=0.03
Trust score:3/5

Substudy of AREDS (717 participants): 5 years of zinc oxide supplementation increased serum zinc (~17% median) versus ~2% in non-zinc groups, with no significant long-term effects on hematocrit, copper, or lipids.

Trust comment: High-quality long-term randomized trial substudy with clear objective biomarker outcomes and large sample for this analysis.

Study Details

PMID:11925463
Participants:717
Impact:no significant difference after 5 years
Trust score:5/5

dysprosium recovery (marker of intestinal absorption measurement)

1 evidences

In 60 children, NaFeEDTA- or FeSO4-fortified soy sauce did not change fractional zinc absorption or total zinc absorption compared with non-fortified soy sauce.

Trust comment: Randomized human study with modest sample (n=60) and direct measurement of zinc absorption; limited by small size.

Study Details

PMID:25582850
Participants:60
Impact:no significant difference among groups (P=0.7498)
Trust score:3/5

diarrhea incidence (children >18 months)

1 evidences

Large randomized trial: therapeutic zinc for diarrhea shortened duration and reduced subsequent diarrhea incidence in children >18 months; preventive zinc or MNP did not reduce diarrhea incidence or duration overall, though preventive zinc increased plasma zinc status.

Trust comment: Large, double-blind, randomized, placebo-controlled trial with prespecified analysis and high adherence; high internal validity.

Study Details

PMID:32612816
Participants:3380
Impact:decreased with therapeutic zinc (TZ 0.40 vs Control 0.58 episodes per 100 days at risk)
Trust score:5/5

diarrhea duration (children >18 months)

1 evidences

Large randomized trial: therapeutic zinc for diarrhea shortened duration and reduced subsequent diarrhea incidence in children >18 months; preventive zinc or MNP did not reduce diarrhea incidence or duration overall, though preventive zinc increased plasma zinc status.

Trust comment: Large, double-blind, randomized, placebo-controlled trial with prespecified analysis and high adherence; high internal validity.

Study Details

PMID:32612816
Participants:3380
Impact:shorter with therapeutic zinc (TZ 1.7 days vs Control 2.0 days; ~0.3 days reduction)
Trust score:5/5

plasma zinc concentration (preventive zinc)

1 evidences

Large randomized trial: therapeutic zinc for diarrhea shortened duration and reduced subsequent diarrhea incidence in children >18 months; preventive zinc or MNP did not reduce diarrhea incidence or duration overall, though preventive zinc increased plasma zinc status.

Trust comment: Large, double-blind, randomized, placebo-controlled trial with prespecified analysis and high adherence; high internal validity.

Study Details

PMID:32612816
Participants:3380
Impact:improved plasma zinc status with preventive zinc (PZ) vs control
Trust score:5/5

plasma zinc concentration (12 mo)

1 evidences

Among hospital-born term low-birth-weight infants, zinc supplementation raised plasma zinc by 12 months but did not change diarrhea or lower respiratory infection prevalence or growth; care-seeking was lower at 9 months.

Trust comment: Large double-blind RCT with good adherence and clear outcomes, though benefits were limited to biochemical status and a small care-seeking change.

Study Details

PMID:19553296
Participants:2052
Impact:increased (zinc 100.2 μg/dL vs control 73.3 μg/dL; difference 26.9 μg/dL)
Trust score:4/5

diarrhea and ALRI prevalence

1 evidences

Among hospital-born term low-birth-weight infants, zinc supplementation raised plasma zinc by 12 months but did not change diarrhea or lower respiratory infection prevalence or growth; care-seeking was lower at 9 months.

Trust comment: Large double-blind RCT with good adherence and clear outcomes, though benefits were limited to biochemical status and a small care-seeking change.

Study Details

PMID:19553296
Participants:2052
Impact:no significant difference at 3, 6, 9, 12 months
Trust score:4/5

care-seeking for illness (9 mo)

1 evidences

Among hospital-born term low-birth-weight infants, zinc supplementation raised plasma zinc by 12 months but did not change diarrhea or lower respiratory infection prevalence or growth; care-seeking was lower at 9 months.

Trust comment: Large double-blind RCT with good adherence and clear outcomes, though benefits were limited to biochemical status and a small care-seeking change.

Study Details

PMID:19553296
Participants:2052
Impact:decreased in zinc group (difference -5.7%; 95% CI -9.9, -1.4)
Trust score:4/5

time to recovery from diarrhoea

1 evidences

In children hospitalized with acute diarrhoea, zinc bisglycinate (15 mg) reduced time to recovery, stool frequency, and duration of IV fluid therapy compared with placebo.

Trust comment: Randomized, double-blind trial with clear clinical outcomes but small sample (n=86), limiting precision.

Study Details

PMID:31578136
Participants:86
Impact:shorter in zinc group (median 44 h) vs control (median 52 h); p=0.01
Trust score:4/5

number of stools during episode

1 evidences

In children hospitalized with acute diarrhoea, zinc bisglycinate (15 mg) reduced time to recovery, stool frequency, and duration of IV fluid therapy compared with placebo.

Trust comment: Randomized, double-blind trial with clear clinical outcomes but small sample (n=86), limiting precision.

Study Details

PMID:31578136
Participants:86
Impact:fewer in zinc group (median 5) vs control (median 7); p=0.02
Trust score:4/5

duration of intravenous fluid therapy / hospital stay

1 evidences

In children hospitalized with acute diarrhoea, zinc bisglycinate (15 mg) reduced time to recovery, stool frequency, and duration of IV fluid therapy compared with placebo.

Trust comment: Randomized, double-blind trial with clear clinical outcomes but small sample (n=86), limiting precision.

Study Details

PMID:31578136
Participants:86
Impact:shorter in zinc group (median 40 h) vs control (median 56 h); p<0.01
Trust score:4/5

total stool output

3 evidences

In hospitalized children with acute diarrhea, replacing ORS with zinc-containing ORS did not reduce stool output or time to recovery compared with standard ORS, likely due to inadequate zinc intake after day 1.

Trust comment: Large double-masked randomized controlled trial in children with clear primary outcomes, though adherence/intake issues limited zinc dosing.

Study Details

PMID:21788757
Participants:500
Impact:no reduction with zinc-ORS vs ORS (median 2.12 vs 1.78 g·kg⁻¹·h⁻¹; no significant difference)
Trust score:4/5

In malnourished young children with acute diarrhea, zinc supplementation tended to reduce stool output and duration and increased serum zinc and weight gain.

Trust comment: Randomized double-blind trial with moderate sample size; some primary outcomes were borderline significant but biochemical and weight changes were significant.

Study Details

PMID:9370894
Participants:111
Impact:-28% (overall; p = 0.06)
Trust score:4/5

In hospitalized dehydrated young children, adding zinc to oral rehydration reduced stool amount and shortened diarrheal illness.

Trust comment: Large double-blind randomized controlled trial in the target population with clear significant effects.

Study Details

PMID:14676592
Participants:287
Impact:-31% (geometric mean ratio 0.69)
Trust score:5/5

stool output per day

1 evidences

In hospitalized dehydrated young children, adding zinc to oral rehydration reduced stool amount and shortened diarrheal illness.

Trust comment: Large double-blind randomized controlled trial in the target population with clear significant effects.

Study Details

PMID:14676592
Participants:287
Impact:-24% (ratio 0.76)
Trust score:5/5

risk of continued/prolonged diarrhea

1 evidences

In hospitalized dehydrated young children, adding zinc to oral rehydration reduced stool amount and shortened diarrheal illness.

Trust comment: Large double-blind randomized controlled trial in the target population with clear significant effects.

Study Details

PMID:14676592
Participants:287
Impact:-24% hazard (relative hazard 0.76); odds ratio 0.49 for ≥5 days and 0.09 for ≥7 days
Trust score:5/5

vitamin D3 status (25-OH-D3)

1 evidences

This study tested zinc (not vitamin D); zinc supplementation modestly increased 25‑OH‑D3 levels in postmenopausal women.

Trust comment: Double-blind randomized trial but small sample and short duration; reported statistically significant biochemical changes.

Study Details

PMID:33607357
Participants:51
Impact:increase (p = 0.049)
Trust score:4/5

serum leptin

1 evidences

This study tested zinc (not vitamin D); zinc supplementation modestly increased 25‑OH‑D3 levels in postmenopausal women.

Trust comment: Double-blind randomized trial but small sample and short duration; reported statistically significant biochemical changes.

Study Details

PMID:33607357
Participants:51
Impact:decrease / inverse correlation with zinc (p = 0.033)
Trust score:4/5

Whole-body bone mineral content (BMC)

1 evidences

In young patients with thalassemia and low bone mass, zinc supplementation increased whole-body bone mass and areal bone density over 18 months.

Trust comment: Randomized placebo-controlled trial with objective DXA outcomes but small completed sample limits precision.

Study Details

PMID:23945720
Participants:32
Impact:+63 g (adjusted mean; P = 0.02)
Trust score:4/5

Areal bone mineral density (aBMD)

1 evidences

In young patients with thalassemia and low bone mass, zinc supplementation increased whole-body bone mass and areal bone density over 18 months.

Trust comment: Randomized placebo-controlled trial with objective DXA outcomes but small completed sample limits precision.

Study Details

PMID:23945720
Participants:32
Impact:+0.023 g/cm² (adjusted mean; P = 0.04)
Trust score:4/5

baseline plasma zinc prevalence low

1 evidences

In children with falciparum malaria, plasma zinc was often low and inversely related to inflammation; zinc supplementation raised plasma zinc from admission to 72 hours.

Trust comment: Large cohort (nested in an RCT) with standardized measures, but observational analyses limit causal inference for clinical outcomes.

Study Details

PMID:15795438
Participants:689
Impact:70% had plasma zinc <9.2 μmol/L on admission
Trust score:4/5

change in plasma zinc with supplementation

1 evidences

In children with falciparum malaria, plasma zinc was often low and inversely related to inflammation; zinc supplementation raised plasma zinc from admission to 72 hours.

Trust comment: Large cohort (nested in an RCT) with standardized measures, but observational analyses limit causal inference for clinical outcomes.

Study Details

PMID:15795438
Participants:689
Impact:increase from admission to 72 h with zinc supplementation (adjusted for CRP/time)
Trust score:4/5

developmental quotient

1 evidences

Zinc improved development and hand-eye coordination in undernourished children, effects were stronger when combined with psychosocial stimulation; zinc reduced diarrhea but did not improve growth.

Trust comment: Randomized controlled trial with clear outcomes and plausible design, moderate sample size.

Study Details

PMID:16087985
Participants:114
Impact:improved (only in children receiving stimulation)
Trust score:4/5

hand and eye coordination

1 evidences

Zinc improved development and hand-eye coordination in undernourished children, effects were stronger when combined with psychosocial stimulation; zinc reduced diarrhea but did not improve growth.

Trust comment: Randomized controlled trial with clear outcomes and plausible design, moderate sample size.

Study Details

PMID:16087985
Participants:114
Impact:improved (zinc alone improved; greater improvement with stimulation)
Trust score:4/5

diarrheal morbidity

1 evidences

Zinc improved development and hand-eye coordination in undernourished children, effects were stronger when combined with psychosocial stimulation; zinc reduced diarrhea but did not improve growth.

Trust comment: Randomized controlled trial with clear outcomes and plausible design, moderate sample size.

Study Details

PMID:16087985
Participants:114
Impact:reduced
Trust score:4/5

energy intake

2 evidences

Supplementing underweight infants with LNS or CSB increased nutrient intakes; LNS increased total energy and protein more than control.

Trust comment: Large randomized trial substudy with objective dietary assessment, though supplement compositions differ and effects are on intake rather than clinical outcomes.

Study Details

PMID:24528807
Participants:188
Impact:+144 kcal (mean difference LNS vs control; 95% CI 37–250; P<0.001)
Trust score:4/5

Four weeks of lipid-based nutritional supplement improved energy intake, weight and iron status in moderately malnourished children but did not change zinc levels.

Trust comment: Small single-blind randomized trial (n=34); LNS produced nutritional gains but no effect on zinc status was detected.

Study Details

PMID:35576279
Participants:34
Impact:+376 kcal/day (611 → 987 kcal/day)
Trust score:3/5

transthyretin

1 evidences

Zinc supplementation increased plasma retinol and transthyretin in preschool children; RBP increase was not significant.

Trust comment: Double-blind, placebo-controlled randomized trial with clear biochemical outcomes and adequate sample.

Study Details

PMID:10702174
Participants:219
Impact:increased (significantly vs placebo)
Trust score:4/5

retinol binding protein (RBP)

1 evidences

Zinc supplementation increased plasma retinol and transthyretin in preschool children; RBP increase was not significant.

Trust comment: Double-blind, placebo-controlled randomized trial with clear biochemical outcomes and adequate sample.

Study Details

PMID:10702174
Participants:219
Impact:no significant change
Trust score:4/5

height-for-age Z-score (HAZ)

1 evidences

Prenatal zinc supplementation did not improve postnatal growth up to 24 months compared with placebo; vitamin A had small effects versus some supplement groups but not versus placebo.

Trust comment: Randomized, double-blind follow-up with moderate sample but largely null results and some subgroup/arm comparisons.

Study Details

PMID:21729462
Participants:343
Impact:no effect vs placebo (small differences vs other supplement groups at some ages)
Trust score:3/5

weight-for-age Z-score (WAZ)

3 evidences

Comparative analyses of neighboring trials found that small-quantity LNS—but not the zinc supplementation regimens used—was associated with improved linear growth (LAZ, WAZ) in infants aged ≈9–15 months.

Trust comment: Large cluster-randomized trials and thorough adjusted analyses support conclusions, though comparisons span two separate trials with differing designs and contexts.

Study Details

PMID:28771493
Participants:4046
Impact:LNS group showed greater WAZ gains versus zinc-supplemented groups (difference remained after adjustment)
Trust score:4/5

Prenatal zinc supplementation did not improve postnatal growth up to 24 months compared with placebo; vitamin A had small effects versus some supplement groups but not versus placebo.

Trust comment: Randomized, double-blind follow-up with moderate sample but largely null results and some subgroup/arm comparisons.

Study Details

PMID:21729462
Participants:343
Impact:no effect vs placebo
Trust score:3/5

2400 Tanzanian infants were randomized to zinc, multivitamins, zinc+multivitamins, or placebo from 6 weeks and followed 18 months; combined Zn+MV modestly reduced weight-for-age decline but zinc alone did not reduce stunting/wasting/underweight incidence.

Trust comment: Large, well-conducted randomized double-blind placebo-controlled trial with long follow-up and clinically meaningful outcomes.

Study Details

PMID:26817503
Participants:2400
Impact:smaller decline in Zn+MV vs placebo (−0.36 ± 0.04 vs −0.50 ± 0.04; P = 0.020)
Trust score:5/5

growth faltering prevalence

1 evidences

Prenatal zinc supplementation did not improve postnatal growth up to 24 months compared with placebo; vitamin A had small effects versus some supplement groups but not versus placebo.

Trust comment: Randomized, double-blind follow-up with moderate sample but largely null results and some subgroup/arm comparisons.

Study Details

PMID:21729462
Participants:343
Impact:no reduction
Trust score:3/5

clinical outcomes (illness score, lung injury score, LOS, ventilation duration)

1 evidences

Zinc supplementation corrected low serum zinc levels but did not improve clinical outcomes such as illness scores, hospital stay, or ventilation duration in infants with severe pneumonia.

Trust comment: Prospective randomized trial but non-blinded with a small sample and no clinical benefit observed.

Study Details

PMID:26684319
Participants:96
Impact:no statistical difference
Trust score:3/5

gestational age

1 evidences

Maternal zinc supplementation (30 mg/d in last two trimesters) did not improve birth weight, gestational age, or other newborn anthropometric outcomes.

Trust comment: Double-blind, placebo-controlled trial with substantial enrollment and objective birth outcome measures, showing null effects.

Study Details

PMID:10617955
Participants:410
Impact:no significant change
Trust score:4/5

incidence of low birth weight/prematurity

1 evidences

Maternal zinc supplementation (30 mg/d in last two trimesters) did not improve birth weight, gestational age, or other newborn anthropometric outcomes.

Trust comment: Double-blind, placebo-controlled trial with substantial enrollment and objective birth outcome measures, showing null effects.

Study Details

PMID:10617955
Participants:410
Impact:no significant change
Trust score:4/5

haemoglobin

3 evidences

Cluster-randomized trial in 6–24 month children comparing rice-based fortified complementary food, sprinkle powder (both containing iron+zinc), or education only for 6 months; fortified complementary food increased haemoglobin and reduced anemia but did not affect linear growth.

Trust comment: Cluster-randomized study with 292 children and objective hematologic endpoints, but zinc was given together with iron so effects specific to zinc cannot be isolated.

Study Details

PMID:25076659
Participants:292
Impact:+1.07 g/dL (mean difference: fortified complementary food vs control; p<0.001)
Trust score:4/5

Infants counseled to eat red meat more frequently from 6–12 months had higher meat intake and improved haemoglobin/hematocrit but no change in zinc status or linear growth at 12 months.

Trust comment: Randomized trial with biochemical measures but small sample (76 completers) and short follow-up limit generalizability.

Study Details

PMID:23945724
Participants:76
Impact:increase (mean change +0.41 g/dL vs −0.13; P=0.01)
Trust score:3/5

Adding vitamin A and zinc to standard iron therapy improved haemoglobin and some iron measures more than iron alone in anaemic women.

Trust comment: Randomized trial with adequate sample size and measured biomarkers, but zinc was given in combination with vitamin A and iron so isolated zinc effect is unclear.

Study Details

PMID:10099942
Participants:216
Impact:+17.9 g/L increase in iron+vitA+zinc group (vs +13.4 g/L with iron alone; +4.5 g/L difference)
Trust score:4/5

iron status (ferritin/TIBC)

1 evidences

Adding vitamin A and zinc to standard iron therapy improved haemoglobin and some iron measures more than iron alone in anaemic women.

Trust comment: Randomized trial with adequate sample size and measured biomarkers, but zinc was given in combination with vitamin A and iron so isolated zinc effect is unclear.

Study Details

PMID:10099942
Participants:216
Impact:improved iron parameters with combination therapy (except serum iron in iron-alone group)
Trust score:4/5

Calcium absorption

1 evidences

Processing (hydrothermal treatment or malting) of barley increased zinc absorption from meals in healthy volunteers, while calcium absorption was unchanged.

Trust comment: Objective isotopic whole-body retention measures in healthy volunteers, but small sample size.

Study Details

PMID:14647214
Participants:22
Impact:no change
Trust score:4/5

premenstrual syndrome symptom severity

1 evidences

Daily zinc supplementation for 24 weeks reduced physical and psychological premenstrual symptoms in female university students compared to placebo.

Trust comment: Triple-masked randomized placebo-controlled trial with clear positive symptom outcomes, but sample is modest and single-center.

Study Details

PMID:35226276
Participants:69
Impact:significant decrease in physical and psychological symptoms (P < 0.001)
Trust score:4/5

social/relationship functioning

1 evidences

Daily zinc supplementation for 24 weeks reduced physical and psychological premenstrual symptoms in female university students compared to placebo.

Trust comment: Triple-masked randomized placebo-controlled trial with clear positive symptom outcomes, but sample is modest and single-center.

Study Details

PMID:35226276
Participants:69
Impact:improved relationship with peers (P = 0.003)
Trust score:4/5

treatment failure (day-5)

1 evidences

In Gambian children with severe pneumonia, adding short-term zinc to standard antibiotic care did not reduce treatment failure but modestly sped recovery of two chest signs.

Trust comment: Large double-blind RCT with clear endpoints and intention-to-treat analysis, high internal validity.

Study Details

PMID:29713463
Participants:604
Impact:≈0% change (Placebo 14.0% → Zinc 14.1%; OR 1.08, P=0.773)
Trust score:5/5

time to resolution — lower chest wall indrawing (LCWI)

1 evidences

In Gambian children with severe pneumonia, adding short-term zinc to standard antibiotic care did not reduce treatment failure but modestly sped recovery of two chest signs.

Trust comment: Large double-blind RCT with clear endpoints and intention-to-treat analysis, high internal validity.

Study Details

PMID:29713463
Participants:604
Impact:24.4 h → 23.0 h (−1.4 h; ratio 0.84; P=0.011)
Trust score:5/5

time to resolution — sternal retraction

1 evidences

In Gambian children with severe pneumonia, adding short-term zinc to standard antibiotic care did not reduce treatment failure but modestly sped recovery of two chest signs.

Trust comment: Large double-blind RCT with clear endpoints and intention-to-treat analysis, high internal validity.

Study Details

PMID:29713463
Participants:604
Impact:18.7 h → 11.0 h (−7.7 h; ratio 0.51; P=0.006)
Trust score:5/5

duration of pregnancy

1 evidences

Adding zinc to prenatal iron–folate supplements did not change pregnancy length or newborn size in this Peruvian cohort.

Trust comment: Large randomized prenatal trial with good follow-up and outcome ascertainment, showing null effects.

Study Details

PMID:10419991
Participants:1016
Impact:No difference (39.4 wk placebo vs 39.5 wk zinc; P>0.05)
Trust score:5/5

length-for-age Z-score (LAZ) / linear growth

1 evidences

In Guatemalan infants 6–12 months old, daily low-dose zinc supplementation or low-phytate maize did not improve linear growth or anthropometric Z-scores.

Trust comment: Well-powered double-masked randomized trial in target age group with appropriate growth outcomes, null results robust.

Study Details

PMID:20335626
Participants:412
Impact:No significant difference between zinc and placebo groups (LAZ decline from −2.1 to −2.5 overall; no treatment effect)
Trust score:5/5

weight-for-length and head circumference Z-scores

1 evidences

In Guatemalan infants 6–12 months old, daily low-dose zinc supplementation or low-phytate maize did not improve linear growth or anthropometric Z-scores.

Trust comment: Well-powered double-masked randomized trial in target age group with appropriate growth outcomes, null results robust.

Study Details

PMID:20335626
Participants:412
Impact:No significant differences between zinc and placebo groups at 12 months
Trust score:5/5

proportion of children with diarrhoea

1 evidences

In rural Indian children, either daily or weekly zinc supplementation for 16 weeks reduced the proportion and incidence of diarrhoeal episodes compared with placebo.

Trust comment: Randomized community trial with clear morbidity endpoints and marked effects, though single-site and moderate size.

Study Details

PMID:12839279
Participants:280
Impact:Placebo 30.8% → Daily zinc 15.8% / Weekly zinc 16.5% (lower in zinc groups)
Trust score:4/5

diarrhoea incidence (episodes per child-year)

1 evidences

In rural Indian children, either daily or weekly zinc supplementation for 16 weeks reduced the proportion and incidence of diarrhoeal episodes compared with placebo.

Trust comment: Randomized community trial with clear morbidity endpoints and marked effects, though single-site and moderate size.

Study Details

PMID:12839279
Participants:280
Impact:Placebo 1.67 → Zinc 0.68–0.69 (relative risk 0.41; 95% CI 0.24–0.71)
Trust score:4/5

behavioral outcomes (internalizing/externalizing)

1 evidences

Six months of zinc supplementation did not change behavioral scores versus placebo, though increases in serum zinc were associated with small decreases in internalizing symptoms.

Trust comment: Large double-blind RCT with validated behavioral measures; treatment group null but biomarker–symptom associations observed.

Study Details

PMID:20881069
Participants:674
Impact:No significant difference between zinc and placebo groups at follow-up
Trust score:4/5

association: serum zinc vs internalizing symptoms

1 evidences

Six months of zinc supplementation did not change behavioral scores versus placebo, though increases in serum zinc were associated with small decreases in internalizing symptoms.

Trust comment: Large double-blind RCT with validated behavioral measures; treatment group null but biomarker–symptom associations observed.

Study Details

PMID:20881069
Participants:674
Impact:Higher serum Zn associated with small decreases in internalizing symptoms (estimate −0.021 points per μg Zn/dL; P=0.02)
Trust score:4/5

salt taste acuity

1 evidences

In older European adults, zinc supplementation (30 mg) modestly improved salt taste acuity in one study site but did not affect other taste qualities overall.

Trust comment: Randomized double-blind intervention with objective taste testing across sites, but heterogeneous site-specific results reduce generalizability.

Study Details

PMID:17651517
Participants:199
Impact:Improved with 30 mg Zn vs placebo in Grenoble subgroup (post-intervention difference); no change in Rome subgroup
Trust score:4/5

sweet/sour/bitter taste acuity

1 evidences

In older European adults, zinc supplementation (30 mg) modestly improved salt taste acuity in one study site but did not affect other taste qualities overall.

Trust comment: Randomized double-blind intervention with objective taste testing across sites, but heterogeneous site-specific results reduce generalizability.

Study Details

PMID:17651517
Participants:199
Impact:No significant change with zinc supplementation
Trust score:4/5

zinc intake

4 evidences

Very low birth weight infants received fortified human milk with or without trace elements; study focused on multiple minerals and growth, not iodine effects.

Trust comment: Prospective randomized trial in VLBW infants with objective biochemical measures but modest sample size and short follow-up.

Study Details

PMID:15448423
Participants:62
Impact:Higher in fortified (BMF) group (P < 0.001)
Trust score:4/5

Daily fortified milk for 27 days increased dietary zinc intake and blood zinc in adolescent girls.

Trust comment: Randomized controlled trial with direct plasma zinc measurement and 108 participants; short duration limits long-term conclusions.

Study Details

PMID:23756585
Participants:108
Impact:+6.2 mg/day (16.7 vs 10.5 mg/day)
Trust score:4/5

A 4-month RCT sending weekly SMS to caregivers increased some infant nutrient intakes; infants in the SMS feeding-practices group had higher protein, calcium, zinc and grain intake at 4–6 months.

Trust comment: Randomized multi-site trial with validated FFQ and significant differences, but short duration and self-reported diet limit generalizability.

Study Details

PMID:36249246
Participants:163
Impact:+1.30 mg median (4.39 vs 3.09 mg; intervention vs control) at 4–6 months
Trust score:4/5

Supplementing underweight infants with LNS or CSB increased nutrient intakes; LNS increased total energy and protein more than control.

Trust comment: Large randomized trial substudy with objective dietary assessment, though supplement compositions differ and effects are on intake rather than clinical outcomes.

Study Details

PMID:24528807
Participants:188
Impact:increased (CSB and LNS vs control; P ≤ 0.001)
Trust score:4/5

prevalence of low zinc intake

2 evidences

Providing a daily animal-source snack for 6 months markedly reduced the prevalence of low zinc intake among women and improved several micronutrient intakes/status markers.

Trust comment: Randomized community nutrition intervention with objective intake and biomarker measures, but zinc change is from food-based intervention rather than isolated zinc supplementation.

Study Details

PMID:28424257
Participants:89
Impact:reduced to 9.6% in ASF group vs 64.7% in controls
Trust score:3/5

Daily fortified milk for 27 days increased dietary zinc intake and blood zinc in adolescent girls.

Trust comment: Randomized controlled trial with direct plasma zinc measurement and 108 participants; short duration limits long-term conclusions.

Study Details

PMID:23756585
Participants:108
Impact:reduced (7 vs 16 participants)
Trust score:4/5

diarrheal recovery

1 evidences

14 days of zinc supplementation raised plasma zinc but did not improve weight gain or speed recovery from diarrhea in hospitalized malnourished children.

Trust comment: Double-blind randomized placebo-controlled inpatient trial (n=87) with clear clinical and biochemical endpoints; biochemical but not clinical benefit observed.

Study Details

PMID:10103334
Participants:87
Impact:no significant change
Trust score:4/5

nutritional status (SGA and anthropometry)

1 evidences

100 mg/day elemental zinc for 3 months raised plasma zinc but did not improve nutritional status measures in CAPD patients.

Trust comment: Small double-blind RCT (n=25) with objective biochemical endpoints but limited power to detect clinical changes.

Study Details

PMID:14968473
Participants:25
Impact:no improvement vs placebo
Trust score:3/5

inflammatory biomarkers

1 evidences

16 weeks of zinc (45 or 90 mg/day) increased circulating zinc and was associated with modest reductions in inflammatory biomarkers in ART-treated people living with HIV.

Trust comment: Phase I open-label randomized pilot (n=52); pilot size and open-label design reduce certainty though biomarker changes were observed.

Study Details

PMID:31609926
Participants:52
Impact:reduced 8–21% in 48–60% of participants
Trust score:3/5

Weight

2 evidences

Daily 10 mg zinc for 5 months increased weight and height, raised circulating IGF-I, and reduced episodes of diarrhea and respiratory infections in growth-retarded children.

Trust comment: Double-blind randomized study with clear growth and infection outcomes and biologic correlates (IGF-I), sample size moderate and well-reported.

Study Details

PMID:8599314
Participants:146
Impact:+0.5 ± 0.1 kg after 5 months (P < 0.001)
Trust score:4/5

Four weeks of lipid-based nutritional supplement improved energy intake, weight and iron status in moderately malnourished children but did not change zinc levels.

Trust comment: Small single-blind randomized trial (n=34); LNS produced nutritional gains but no effect on zinc status was detected.

Study Details

PMID:35576279
Participants:34
Impact:+0.6 kg (17.5 → 18.1 kg)
Trust score:3/5

teacher-rated oppositional behavior

1 evidences

In lead-exposed first graders, 6 months of zinc (alone or with iron) produced no consistent improvements in parent- or teacher-rated behavior.

Trust comment: Large double-blind randomized trial with robust sample and standardized rating scales; effects were mostly non-significant and based on subjective ratings.

Study Details

PMID:16291354
Participants:602
Impact:↑ likelihood of no longer having clinically-significant teacher-rated oppositional behavior (no effect size provided)
Trust score:4/5

hyperactivity (teacher-rated)

1 evidences

In lead-exposed first graders, 6 months of zinc (alone or with iron) produced no consistent improvements in parent- or teacher-rated behavior.

Trust comment: Large double-blind randomized trial with robust sample and standardized rating scales; effects were mostly non-significant and based on subjective ratings.

Study Details

PMID:16291354
Participants:602
Impact:+1.1 points overall (increase from baseline); no treatment effect on mean change
Trust score:4/5

cognitive problems (parent-rated)

1 evidences

In lead-exposed first graders, 6 months of zinc (alone or with iron) produced no consistent improvements in parent- or teacher-rated behavior.

Trust comment: Large double-blind randomized trial with robust sample and standardized rating scales; effects were mostly non-significant and based on subjective ratings.

Study Details

PMID:16291354
Participants:602
Impact:parent mean score declined by 2.5 points at follow-up (overall), no treatment effect on mean change
Trust score:4/5

length/linear growth

2 evidences

Preterm infants fed a nutrient-enriched formula (higher protein, Ca, P, and zinc) had greater linear growth, bone mineral content, and lean mass by 3 months corrected age compared with standard formula.

Trust comment: Blinded randomized nutrition trial with objective body-composition outcomes but multinutrient enrichment (not zinc alone) limits attribution solely to zinc.

Study Details

PMID:9738713
Participants:60
Impact:increased (P<0.05)
Trust score:4/5

Infants born small for gestational age who received daily zinc showed greater weight and length gains over the first 6 months versus placebo.

Trust comment: Small double-blind randomized trial with clear anthropometric outcomes and significant effects on growth in this specific population.

Study Details

PMID:7636643
Participants:68
Impact:+1.5 cm at 6 months (64.9 ±1.8 cm vs 63.4 ±3.5 cm; p < 0.01)
Trust score:4/5

rhinovirus infection incidence

1 evidences

Intranasal zinc gluconate did not prevent rhinovirus infection or reduce cold symptoms after experimental inoculation.

Trust comment: Randomized placebo-controlled experimental human challenge study with clear negative findings.

Study Details

PMID:11692298
Participants:91
Impact:placebo 74% vs zinc 78% (no significant effect)
Trust score:4/5

cold symptom severity (total score, rhinorrhea, nasal obstruction)

1 evidences

Intranasal zinc gluconate did not prevent rhinovirus infection or reduce cold symptoms after experimental inoculation.

Trust comment: Randomized placebo-controlled experimental human challenge study with clear negative findings.

Study Details

PMID:11692298
Participants:91
Impact:no effect of intranasal zinc on total symptom score, rhinorrhea, or nasal obstruction
Trust score:4/5

development of clinical colds among infected

1 evidences

Intranasal zinc gluconate did not prevent rhinovirus infection or reduce cold symptoms after experimental inoculation.

Trust comment: Randomized placebo-controlled experimental human challenge study with clear negative findings.

Study Details

PMID:11692298
Participants:91
Impact:no difference in proportion developing clinical colds
Trust score:4/5

Candida infections

1 evidences

In patients receiving head/neck radiotherapy, oral zinc supplementation appeared to prevent some oropharyngeal infections (notably Candida and staphylococci).

Trust comment: Small clinical study in immunocompromised patients with indications of benefit for some pathogens but limited sample size and detail.

Study Details

PMID:12964500
Participants:30
Impact:reduced/ prevented by zinc supplementation (no exact counts provided)
Trust score:3/5

staphylococcal infections

1 evidences

In patients receiving head/neck radiotherapy, oral zinc supplementation appeared to prevent some oropharyngeal infections (notably Candida and staphylococci).

Trust comment: Small clinical study in immunocompromised patients with indications of benefit for some pathogens but limited sample size and detail.

Study Details

PMID:12964500
Participants:30
Impact:reduced/ prevented by zinc supplementation (no exact counts provided)
Trust score:3/5

group A beta-haemolytic streptococci and Streptococcus pneumoniae

1 evidences

In patients receiving head/neck radiotherapy, oral zinc supplementation appeared to prevent some oropharyngeal infections (notably Candida and staphylococci).

Trust comment: Small clinical study in immunocompromised patients with indications of benefit for some pathogens but limited sample size and detail.

Study Details

PMID:12964500
Participants:30
Impact:no effect of zinc on these pathogens
Trust score:3/5

height-for-age in children stunted at baseline

1 evidences

Weekly or daily micronutrient supplements including zinc raised hemoglobin, serum zinc, and retinol versus placebo; growth improved only in children who were stunted at baseline.

Trust comment: Double-blind placebo-controlled trial with clear biomarker improvements and subgroup growth benefit; moderate sample size.

Study Details

PMID:9925127
Participants:163
Impact:+0.48 z (daily) and +0.37 z (weekly) at follow-up (both P < 0.001)
Trust score:4/5

iron absorption

3 evidences

Sprinkles provided measurable absorbed zinc (dose‑dependent total absorbed) and did not affect iron absorption in young children.

Trust comment: Randomized controlled trial using isotopic tracers in young children (n=75); robust methods for absorption assessment.

Study Details

PMID:16549451
Participants:75
Impact:no difference between groups (no effect of zinc or ascorbic acid)
Trust score:4/5

20 mg zinc daily for 2 months had no effect on iron absorption or iron status in non‑anemic Chilean women.

Trust comment: Randomized controlled trial with isotope iron absorption measurement but modest sample size (n=44).

Study Details

PMID:18586462
Participants:44
Impact:no difference between zinc and placebo groups (no group‑wise effect)
Trust score:4/5

Adding Na2EDTA to fortified rice flour increased iron and zinc absorption in schoolchildren.

Trust comment: Randomized trial with tracer-based absorption measures and reasonable completion rate, but moderate sample size.

Study Details

PMID:15514271
Participants:48
Impact:4.7% vs 2.2% (increase ≈ +2.5 percentage points; P < 0.01)
Trust score:4/5

diarrhoea duration

2 evidences

Zinc given during acute diarrhoea shortened episodes and substantially reduced the risk of prolonged diarrhoea in young children.

Trust comment: Large double-blind randomized controlled factorial trial with clinically important and significant outcomes.

Study Details

PMID:10102147
Participants:678
Impact:-13% (reduction; P = 0.03)
Trust score:5/5

Two-week zinc supplementation raised plasma zinc by day 14 but did not significantly shorten diarrhoea duration or reduce severity or incidence versus control.

Trust comment: Randomized clinical trial with adequate sample but open-label and non-placebo-controlled, limiting clinical inference despite biomarker change.

Study Details

PMID:16354711
Participants:280
Impact:mean 3.02 vs 3.67 days (zinc vs control); no significant difference
Trust score:3/5

prolonged diarrhoea (>7 d) rate

1 evidences

Zinc given during acute diarrhoea shortened episodes and substantially reduced the risk of prolonged diarrhoea in young children.

Trust comment: Large double-blind randomized controlled factorial trial with clinically important and significant outcomes.

Study Details

PMID:10102147
Participants:678
Impact:-43% (reduction; P = 0.017)
Trust score:5/5

pneumonia resolution time

1 evidences

Adjunctive zinc shortened pneumonia resolution time, reduced fever duration, and shortened hospital stays in children with pneumonia.

Trust comment: Double-blind placebo-controlled RCT with clear significant clinical endpoints but modest sample size.

Study Details

PMID:31821466
Participants:91
Impact:48 h vs 72 h (shorter by 24 h; HR = 0.585, 95% CI 0.377–0.908)
Trust score:4/5

hospitalization duration

1 evidences

Adjunctive zinc shortened pneumonia resolution time, reduced fever duration, and shortened hospital stays in children with pneumonia.

Trust comment: Double-blind placebo-controlled RCT with clear significant clinical endpoints but modest sample size.

Study Details

PMID:31821466
Participants:91
Impact:96 h vs 144 h (shorter by 48 h; P = 0.008)
Trust score:4/5

fever resolution time

1 evidences

Adjunctive zinc shortened pneumonia resolution time, reduced fever duration, and shortened hospital stays in children with pneumonia.

Trust comment: Double-blind placebo-controlled RCT with clear significant clinical endpoints but modest sample size.

Study Details

PMID:31821466
Participants:91
Impact:24 h vs 42 h (shorter by 18 h; P = 0.002)
Trust score:4/5

iron absorption (ferrous sulfate vs fumarate)

1 evidences

H. pylori infection reduced iron absorption from fortified bread; ferrous sulfate was absorbed much better than ferrous fumarate.

Trust comment: Crossover tracer study with clear biochemical endpoints and matched groups, but sample size is modest.

Study Details

PMID:21748303
Participants:50
Impact:6.9% vs 0.5% (ferrous sulfate > fumarate; P < 0.001)
Trust score:4/5

effect of H. pylori on iron absorption

1 evidences

H. pylori infection reduced iron absorption from fortified bread; ferrous sulfate was absorbed much better than ferrous fumarate.

Trust comment: Crossover tracer study with clear biochemical endpoints and matched groups, but sample size is modest.

Study Details

PMID:21748303
Participants:50
Impact:H. pylori-negative absorbed more (e.g., ferrous sulfate 10.5% vs 4.4% in positives; P < 0.001)
Trust score:4/5

skin zinc content

1 evidences

Intravenous trace element supplementation including zinc increased zinc in burned skin and reduced local skin protein breakdown but did not change whole-body metabolism.

Trust comment: Randomized placebo-controlled study with mechanistic isotope measurements but small overall sample.

Study Details

PMID:17490966
Participants:21
Impact:Increased in burned skin by day 20 (P = 0.03)
Trust score:4/5

skin protein catabolism

1 evidences

Intravenous trace element supplementation including zinc increased zinc in burned skin and reduced local skin protein breakdown but did not change whole-body metabolism.

Trust comment: Randomized placebo-controlled study with mechanistic isotope measurements but small overall sample.

Study Details

PMID:17490966
Participants:21
Impact:Reduced (supernatant-to-plasma 13C enrichment ratio at 6 h: 0.592 vs 0.262; P = 0.03)
Trust score:4/5

whole-body substrate turnover

1 evidences

Intravenous trace element supplementation including zinc increased zinc in burned skin and reduced local skin protein breakdown but did not change whole-body metabolism.

Trust comment: Randomized placebo-controlled study with mechanistic isotope measurements but small overall sample.

Study Details

PMID:17490966
Participants:21
Impact:No significant change
Trust score:4/5

diarrhoea incidence

4 evidences

Children given a mixture (Lactobacillus GG + vitamins B/C + zinc) had fewer nosocomial infections, less diarrhoea, and shorter hospital stays than placebo.

Trust comment: Randomized trial but intervention was a multi-component mixture (including zinc), so effects cannot be attributed to zinc alone.

Study Details

PMID:27464469
Participants:90
Impact:−20 percentage points (4% vs 24%)
Trust score:3/5

In young Burkinabe children, adding 5 or 10 mg zinc to daily SQ-LNS or giving a 5 mg zinc tablet did not reduce diarrhoea, malaria, fever, or respiratory infections compared with SQ-LNS without added zinc.

Trust comment: Large, double-blind, cluster-randomised trial with rigorous surveillance and appropriate analyses; results directly assess zinc interventions.

Study Details

PMID:26362661
Participants:2364
Impact:no significant change
Trust score:5/5

Daily zinc-containing sprinkles did not significantly reduce diarrhoea or respiratory infections in institutionalized young children over 90 days.

Trust comment: Randomized double-blind trial with adequate reporting but no significant effects and moderate sample size.

Study Details

PMID:23664200
Participants:143
Impact:14.7% (zinc) vs 19.1% (control); non-significant (RR = 0.77, P = 0.5088)
Trust score:4/5

Large community randomized trial comparing zinc formulations/doses found no effect on diarrhea incidence, and a modest improvement in linear growth (smaller decline in LAZ) with the daily high‑zinc/low‑iron MNP formulation.

Trust comment: Large, well-powered randomized community trial with frequent morbidity surveillance and appropriate analyses; high confidence in null diarrhea result and modest growth finding.

Study Details

PMID:35015856
Participants:2886
Impact:No difference across intervention groups (mean incidence 1.21 episodes per 100 days)
Trust score:5/5

acute respiratory infection incidence

1 evidences

Daily zinc-containing sprinkles did not significantly reduce diarrhoea or respiratory infections in institutionalized young children over 90 days.

Trust comment: Randomized double-blind trial with adequate reporting but no significant effects and moderate sample size.

Study Details

PMID:23664200
Participants:143
Impact:60% (zinc) vs 48.5% (control); non-significant (RR = 1.24, P = 0.1825)
Trust score:4/5

lipoprotein metabolism

1 evidences

Short‑term low‑level zinc (total ~40 mg/d) did not change lipids, blood clotting markers, or copper status in healthy men.

Trust comment: Randomized double‑blind placebo‑controlled trial but small sample (n=38) and short duration; methods appropriate.

Study Details

PMID:12835492
Participants:38
Impact:no significant change
Trust score:4/5

hemostasis markers

1 evidences

Short‑term low‑level zinc (total ~40 mg/d) did not change lipids, blood clotting markers, or copper status in healthy men.

Trust comment: Randomized double‑blind placebo‑controlled trial but small sample (n=38) and short duration; methods appropriate.

Study Details

PMID:12835492
Participants:38
Impact:no significant change
Trust score:4/5

copper status (putative indices)

1 evidences

Short‑term low‑level zinc (total ~40 mg/d) did not change lipids, blood clotting markers, or copper status in healthy men.

Trust comment: Randomized double‑blind placebo‑controlled trial but small sample (n=38) and short duration; methods appropriate.

Study Details

PMID:12835492
Participants:38
Impact:no significant change
Trust score:4/5

iron status indicators

1 evidences

20 mg zinc daily for 2 months had no effect on iron absorption or iron status in non‑anemic Chilean women.

Trust comment: Randomized controlled trial with isotope iron absorption measurement but modest sample size (n=44).

Study Details

PMID:18586462
Participants:44
Impact:no significant change between groups
Trust score:4/5

iron/copper status and lipid profile

1 evidences

6 months of 15–30 mg/day zinc raised serum and urinary zinc with no major overall adverse effects on iron, copper status or lipids, though 30 mg/day showed some age/sex‑dependent changes.

Trust comment: Large randomized double‑blind study (n=387) with dose arms and 6‑month follow‑up; well conducted though subgroup signals noted.

Study Details

PMID:17313720
Participants:387
Impact:no major adverse changes overall; 30 mg/d produced some age‑ and sex‑dependent alterations
Trust score:4/5

pregnancy/maternal and fetal outcomes (LGA, SGA, PROM, preterm labor, preeclampsia, bleeding)

1 evidences

In this large trial, prenatal zinc supplementation (~44 mg total per day) produced no measurable benefits for mother or baby on the reported outcomes.

Trust comment: Large double‑blind randomized controlled trial (n=1,206) with clinical outcomes and good power; reliable negative finding.

Study Details

PMID:8906006
Participants:1206
Impact:no difference versus placebo
Trust score:5/5

Growth velocity

1 evidences

In a small crossover trial ZA (contains zinc) increased growth velocity in a subset of prepubertal children with low growth velocity.

Trust comment: Small crossover study with preliminary results (n=24 completers); suggests effect in subset but limited sample size.

Study Details

PMID:7626370
Participants:24
Impact:in subset (n=15) ZA: 3.105→5.4 mm/month (≈+2.30 mm/mo); ZA increase +2.44 mm/mo vs AA +0.44 mm/mo (p<0.05)
Trust score:3/5

percent zinc absorbed

1 evidences

Sprinkles provided measurable absorbed zinc (dose‑dependent total absorbed) and did not affect iron absorption in young children.

Trust comment: Randomized controlled trial using isotopic tracers in young children (n=75); robust methods for absorption assessment.

Study Details

PMID:16549451
Participants:75
Impact:no difference between low (6.4%) and high (7.5%) zinc dose groups
Trust score:4/5

total zinc absorbed

1 evidences

Sprinkles provided measurable absorbed zinc (dose‑dependent total absorbed) and did not affect iron absorption in young children.

Trust comment: Randomized controlled trial using isotopic tracers in young children (n=75); robust methods for absorption assessment.

Study Details

PMID:16549451
Participants:75
Impact:LoZn geometric mean 0.31 mg vs HiZn 0.82 mg (HiZn > LoZn, p=0.0004)
Trust score:4/5

oral bacterial counts (teeth, tongue, buccal mucosa, gingiva, saliva)

1 evidences

Zinc+arginine toothpastes used twice daily reduced mouth bacteria across multiple sites after regular use.

Trust comment: Randomized, double-blind, parallel-group trial with good sample size and clear statistically significant results.

Study Details

PMID:30620868
Participants:173
Impact:-29% to -41% bacterial counts (12 h after 29 days)
Trust score:4/5

time to fever resolution

1 evidences

Adding zinc to standard malaria treatment raised blood zinc but did not improve fever reduction, parasite clearance, or hemoglobin.

Trust comment: Large multicenter double-blind RCT with clear clinical endpoints and objective lab measures.

Study Details

PMID:12324294
Participants:1087
Impact:no difference (median 24.2 h zinc vs 24.0 h placebo; P = 0.37)
Trust score:4/5

parasitemia reduction (≥75% in 72 h)

1 evidences

Adding zinc to standard malaria treatment raised blood zinc but did not improve fever reduction, parasite clearance, or hemoglobin.

Trust comment: Large multicenter double-blind RCT with clear clinical endpoints and objective lab measures.

Study Details

PMID:12324294
Participants:1087
Impact:73.4% zinc vs 77.6% placebo (P = 0.11), no significant benefit
Trust score:4/5

diarrhea prevalence and growth

1 evidences

Daily consumption of low-dose, highly bioavailable zinc-fortified filtered water increased children's blood zinc and reduced zinc deficiency but did not change diarrhea or growth.

Trust comment: Double-blind RCT with objective biochemical outcomes; modest sample size and limited power for clinical endpoints.

Study Details

PMID:26468121
Participants:277
Impact:no detectable effect (study not powered/duration insufficient)
Trust score:4/5

treatment failure (need to change antibiotics or hospitalization)

1 evidences

Zinc given with antibiotics did not reduce treatment failure or speed recovery from pneumonia but increased short-term regurgitation/vomiting.

Trust comment: Large double-blind placebo-controlled RCT in a zinc-deficient population with clinically relevant endpoints.

Study Details

PMID:20375190
Participants:2628
Impact:no difference (nonsevere OR 0.95; severe OR 0.97)
Trust score:4/5

time to recovery from pneumonia

1 evidences

Zinc given with antibiotics did not reduce treatment failure or speed recovery from pneumonia but increased short-term regurgitation/vomiting.

Trust comment: Large double-blind placebo-controlled RCT in a zinc-deficient population with clinically relevant endpoints.

Study Details

PMID:20375190
Participants:2628
Impact:no difference (median nonsevere 2 d; severe 4 d)
Trust score:4/5

regurgitation/vomiting after supplementation

1 evidences

Zinc given with antibiotics did not reduce treatment failure or speed recovery from pneumonia but increased short-term regurgitation/vomiting.

Trust comment: Large double-blind placebo-controlled RCT in a zinc-deficient population with clinically relevant endpoints.

Study Details

PMID:20375190
Participants:2628
Impact:increased: 37% zinc vs 13% placebo during supplementation
Trust score:4/5

zinc deficiency prevalence / serum zinc

1 evidences

Sprinkles and Foodlets improved infants' zinc status more than Drops, but there was no benefit for growth or vitamin A/D status.

Trust comment: Randomized trial with multiple supplement arms and biochemical outcomes, though context-specific to local diet.

Study Details

PMID:21750564
Participants:362
Impact:greater reductions in zinc deficiency with Foodlets and Sprinkles vs Drops (statistically significant)
Trust score:4/5

haemoglobin / iron status

1 evidences

Sprinkles and Foodlets improved infants' zinc status more than Drops, but there was no benefit for growth or vitamin A/D status.

Trust comment: Randomized trial with multiple supplement arms and biochemical outcomes, though context-specific to local diet.

Study Details

PMID:21750564
Participants:362
Impact:iron status improved with all treatments; Drops showed larger Hb and ferritin changes
Trust score:4/5

serum calcium

1 evidences

Postmenopausal osteoporotic women took zinc or placebo for 60 days; zinc raised serum zinc but did not change serum calcium.

Trust comment: Randomized double-blind placebo-controlled RCT with clear biochemical endpoints but small sample (n=60).

Study Details

PMID:23879079
Participants:60
Impact:no change (8.6 vs 9.1 mg/dL)
Trust score:4/5

inattention (ADHD)

1 evidences

Children with ADHD on methylphenidate received zinc or placebo for 6 weeks; zinc augmentation improved inattention but not total, hyperactivity, or impulsivity scores.

Trust comment: Double-blind RCT but small sample (n=60) and limited magnitude data for the reported effect.

Study Details

PMID:31841818
Participants:60
Impact:improved (statistically significant; magnitude not reported)
Trust score:3/5

diarrheal incidence

2 evidences

Randomized double-blind trial in 100 low-birth-weight infants: daily 5 mg elemental zinc from birth to 1 year reduced diarrhea episodes and improved weight/linear growth at 1 year.

Trust comment: Well-designed randomized, double-blind, placebo-controlled community trial but relatively small sample (n=100); breastfeeding modified effects.

Study Details

PMID:14654605
Participants:100
Impact:-29.5% (1.93 -> 1.36 episodes per child-year)
Trust score:4/5

Children 6–35 months received daily zinc or control for 6 months; zinc reduced diarrheal episodes and days in children older than 11 months, especially boys.

Trust comment: Community double-blind randomized trial with moderate-large sample and clinically relevant outcomes (age-stratified effects reported).

Study Details

PMID:9250122
Participants:579
Impact:−26% (boys >11 mo), −17% (girls >11 mo); −17% overall in >11 mo/low-zinc subgroups
Trust score:4/5

diarrheal prevalence (total diarrheal days)

1 evidences

Children 6–35 months received daily zinc or control for 6 months; zinc reduced diarrheal episodes and days in children older than 11 months, especially boys.

Trust comment: Community double-blind randomized trial with moderate-large sample and clinically relevant outcomes (age-stratified effects reported).

Study Details

PMID:9250122
Participants:579
Impact:−35% (boys >11 mo), −19% (girls >11 mo)
Trust score:4/5

duration of persistent diarrhea

1 evidences

Children with persistent diarrhea received zinc (20 mg) +/- other micronutrients or placebo for 2 weeks; zinc raised plasma zinc and shortened diarrheal duration in some groups.

Trust comment: Well-conducted community randomized double-blind trial with objective biochemical measures and clinical outcomes (moderate sample, subgroup effects).

Study Details

PMID:10431116
Participants:412
Impact:−28% (Z overall); −33% (girls in Z+VM subgroup)
Trust score:4/5

oral malodor (organoleptic score)

1 evidences

A 3-week double-blind trial in adults found a dentifrice containing zinc plus arginine produced substantially greater overnight breath odor reduction than a regular fluoride dentifrice.

Trust comment: Randomized double-blind clinical trial with 80 completers and clear, significant results, though industry-formulated product.

Study Details

PMID:30620870
Participants:80
Impact:test: −38.9% vs control: −11.6% from baseline; relative improvement −30.8% (p<0.001)
Trust score:4/5

maternal plasma zinc concentration (30 wk)

1 evidences

Nested substudy of a prenatal trial in The Gambia: maternal supplementation affected maternal zinc status and was associated with altered placental expression of zinc transporter genes.

Trust comment: Well-powered randomized prenatal trial substudy (n≈301) with rigorous assays and adjusted analyses; some outcomes complex due to multiple intervention arms.

Study Details

PMID:28515164
Participants:301
Impact:higher in MMN arm than FeFol, PE, and PE+MMN arms (P<0.001)
Trust score:4/5

placental zinc importer (ZIP) mRNA expression

1 evidences

Nested substudy of a prenatal trial in The Gambia: maternal supplementation affected maternal zinc status and was associated with altered placental expression of zinc transporter genes.

Trust comment: Well-powered randomized prenatal trial substudy (n≈301) with rigorous assays and adjusted analyses; some outcomes complex due to multiple intervention arms.

Study Details

PMID:28515164
Participants:301
Impact:ZIP1, ZIP4, ZIP8 mRNA markedly lower in PE+MMN arm versus FeFol/PE (e.g., ZIP1 ~85% lower vs PE; ZIP4 and ZIP8 substantially lower; P≤0.01)
Trust score:4/5

placental transferrin receptor (TfR1) mRNA expression (iron transporter)

1 evidences

Nested substudy of a prenatal trial in The Gambia: maternal supplementation affected maternal zinc status and was associated with altered placental expression of zinc transporter genes.

Trust comment: Well-powered randomized prenatal trial substudy (n≈301) with rigorous assays and adjusted analyses; some outcomes complex due to multiple intervention arms.

Study Details

PMID:28515164
Participants:301
Impact:upregulated (~30–49% higher) in LNS (PE/PE+MMN) arms versus FeFol (P≤0.031)
Trust score:4/5

seizure frequency

1 evidences

In a 6-month randomized double-blind trial, oral zinc (1 mg/kg/day) produced a seizure frequency reduction in a subset of treated children with intractable epilepsy.

Trust comment: Randomized double-blind design but small single-center trial with modest benefit in a minority of participants.

Study Details

PMID:26415035
Participants:45
Impact:reduced in 31% of zinc-treated children
Trust score:3/5

C-peptide

1 evidences

Four weeks of daily 9 mg zinc had no effect on insulin secretion or insulin resistance in healthy 9–11‑year‑old girls.

Trust comment: Randomized controlled trial in adolescents with adequate reporting; modest duration (4 weeks) limits longer-term conclusions.

Study Details

PMID:28592518
Participants:147
Impact:No significant change with zinc; placebo black subgroup +15.7% (P=0.06)
Trust score:4/5

fasting insulin

1 evidences

Four weeks of daily 9 mg zinc had no effect on insulin secretion or insulin resistance in healthy 9–11‑year‑old girls.

Trust comment: Randomized controlled trial in adolescents with adequate reporting; modest duration (4 weeks) limits longer-term conclusions.

Study Details

PMID:28592518
Participants:147
Impact:No significant change with zinc
Trust score:4/5

HOMA2-IR (insulin resistance)

1 evidences

Four weeks of daily 9 mg zinc had no effect on insulin secretion or insulin resistance in healthy 9–11‑year‑old girls.

Trust comment: Randomized controlled trial in adolescents with adequate reporting; modest duration (4 weeks) limits longer-term conclusions.

Study Details

PMID:28592518
Participants:147
Impact:No significant change with zinc; placebo black subgroup +17.7% (P=0.06)
Trust score:4/5

Weight gain rate

1 evidences

Weekly low-dose zinc (20 mg) alone or with iron from 6–12 months did not affect infant weight or length gain in this population.

Trust comment: Large randomized trial with clear anthropometric endpoints showing null effects for growth at the tested dose/frequency.

Study Details

PMID:17882136
Participants:645
Impact:no effect (no significant difference vs control)
Trust score:4/5

Length gain rate

1 evidences

Weekly low-dose zinc (20 mg) alone or with iron from 6–12 months did not affect infant weight or length gain in this population.

Trust comment: Large randomized trial with clear anthropometric endpoints showing null effects for growth at the tested dose/frequency.

Study Details

PMID:17882136
Participants:645
Impact:no effect (no significant difference vs control)
Trust score:4/5

Wexner incontinence score

1 evidences

Topical zinc‑aluminium ointment significantly improved fecal incontinence scores and quality of life versus placebo after 3 weeks.

Trust comment: Double‑blind randomized trial with clear outcome improvements but modest sample size (44 completers).

Study Details

PMID:21781231
Participants:44
Impact:Treatment: −8.1 points (16.6→8.5); Placebo: −3.6 points (16.7→13.1); treatment superior (P=0.001)
Trust score:4/5

Fecal Incontinence Quality of Life (FIQL)

1 evidences

Topical zinc‑aluminium ointment significantly improved fecal incontinence scores and quality of life versus placebo after 3 weeks.

Trust comment: Double‑blind randomized trial with clear outcome improvements but modest sample size (44 completers).

Study Details

PMID:21781231
Participants:44
Impact:Significant improvement in all FIQL parameters in treatment vs placebo
Trust score:4/5

Iron status indicators (Hb, ferritin, TfR)

1 evidences

Weekly zinc supplementation increased serum zinc in infants; iron indicators were unchanged and serum copper decreased with zinc or iron supplementation.

Trust comment: Double‑blind, randomized community trial with clear biochemical endpoints and adequate group sizes.

Study Details

PMID:16140896
Participants:333
Impact:No significant change between groups after 6 months
Trust score:4/5

Serum copper concentration

1 evidences

Weekly zinc supplementation increased serum zinc in infants; iron indicators were unchanged and serum copper decreased with zinc or iron supplementation.

Trust comment: Double‑blind, randomized community trial with clear biochemical endpoints and adequate group sizes.

Study Details

PMID:16140896
Participants:333
Impact:Decreased after 6 months in groups receiving zinc or iron
Trust score:4/5

alkaline phosphatase activity

3 evidences

A 4-month randomized trial in women with low iron stores tested dietary advice, iron supplement, or placebo and measured zinc status; iron supplements with meals appeared to lower zinc status.

Trust comment: Randomized, partially blinded placebo-controlled human trial with measured biomarkers; moderate risk from subgroup sizes but overall reliable.

Study Details

PMID:20416130
Participants:78
Impact:followed similar trend to serum zinc (no improvement with iron supplement)
Trust score:4/5

In 60 patients with traumatic fractures, 50 mg elemental zinc daily for 60 days raised serum zinc and alkaline phosphatase and improved radiographic callus formation versus placebo.

Trust comment: Randomized double-blind placebo-controlled clinical trial in humans with clear outcomes, but moderate sample size.

Study Details

PMID:18813411
Participants:60
Impact:significant increase (zinc group vs placebo)
Trust score:4/5

Very low birth weight infants received fortified human milk with or without trace elements; study focused on multiple minerals and growth, not iodine effects.

Trust comment: Prospective randomized trial in VLBW infants with objective biochemical measures but modest sample size and short follow-up.

Study Details

PMID:15448423
Participants:62
Impact:Lower median AP in BMF vs FM85 at 6 weeks (379 vs 436 IU/L; P < 0.01)
Trust score:4/5

callus formation / fracture healing

1 evidences

In 60 patients with traumatic fractures, 50 mg elemental zinc daily for 60 days raised serum zinc and alkaline phosphatase and improved radiographic callus formation versus placebo.

Trust comment: Randomized double-blind placebo-controlled clinical trial in humans with clear outcomes, but moderate sample size.

Study Details

PMID:18813411
Participants:60
Impact:significantly improved radiographic callus progression (zinc vs placebo)
Trust score:4/5

acute lower respiratory infection (ALRI) incidence

1 evidences

Daily 10 mg elemental zinc for 6 months in 6–35-month-old children reduced incidence of acute lower respiratory infections and lowered prevalence of low plasma zinc.

Trust comment: Large double-blind randomized controlled trial in children with clinically meaningful outcomes and statistical adjustment.

Study Details

PMID:9651405
Participants:609
Impact:0.19 vs 0.35 episodes/child/year (zinc vs control); 45% reduction (95% CI 10%–67%)
Trust score:5/5

plasma zinc <60 µg/dL prevalence

1 evidences

Daily 10 mg elemental zinc for 6 months in 6–35-month-old children reduced incidence of acute lower respiratory infections and lowered prevalence of low plasma zinc.

Trust comment: Large double-blind randomized controlled trial in children with clinically meaningful outcomes and statistical adjustment.

Study Details

PMID:9651405
Participants:609
Impact:decreased from 35.6% to 11.6% in zinc group (vs increase to 43.6% in control)
Trust score:5/5

amount of zinc absorbed (AZ)

1 evidences

In a crossover stable-isotope study in Kenyan preschoolers, adding ~16 g dried house crickets to maize porridge increased the amount of zinc absorbed compared with low-zinc porridge (and exceeded absorption from a high-Zn fortified meal).

Trust comment: Rigorous crossover stable-isotope study in young children with direct absorption measures; modest sample size and dropouts noted.

Study Details

PMID:39856054
Participants:25
Impact:WC 0.36 mg (0.30–0.43) vs LZ 0.14 mg (0.11–0.16) — WC 2.6× LZ (P<0.001); WC 1.5× HZ (0.36 vs 0.24 mg; P=0.004); EC 0.34 mg
Trust score:4/5

TB skin-test induration size

1 evidences

In 50 adults, topical 1% elemental zinc cream applied to PPD sites increased TB and Candida skin-test induration and raised the likelihood of positive TB tests, especially in zinc-deficient individuals.

Trust comment: Randomized double-blind within-subject design in humans with clear, biologically plausible effects; sample size moderate.

Study Details

PMID:18214192
Participants:50
Impact:average 32% larger with topical zinc vs placebo (p<0.001)
Trust score:4/5

TB skin-test positivity rate

1 evidences

In 50 adults, topical 1% elemental zinc cream applied to PPD sites increased TB and Candida skin-test induration and raised the likelihood of positive TB tests, especially in zinc-deficient individuals.

Trust comment: Randomized double-blind within-subject design in humans with clear, biologically plausible effects; sample size moderate.

Study Details

PMID:18214192
Participants:50
Impact:94% positive with zinc cream vs 76% with placebo (p=0.01)
Trust score:4/5

effect by plasma zinc status

1 evidences

In 50 adults, topical 1% elemental zinc cream applied to PPD sites increased TB and Candida skin-test induration and raised the likelihood of positive TB tests, especially in zinc-deficient individuals.

Trust comment: Randomized double-blind within-subject design in humans with clear, biologically plausible effects; sample size moderate.

Study Details

PMID:18214192
Participants:50
Impact:augmentation greater in zinc-deficient persons; no effect in those with normal plasma zinc
Trust score:4/5

asthma symptom control

1 evidences

Children with asthma who received teach-back education plus zinc had better asthma knowledge, medication use, and symptom control at one month; immunological markers and time to symptom relief improved in both groups.

Trust comment: Randomized pediatric study but zinc was given together with teach-back education so effects are confounded; moderate sample and short follow-up.

Study Details

PMID:40387134
Participants:81
Impact:increased (significantly higher in observation group at 1 month)
Trust score:3/5

medication adherence

1 evidences

Children with asthma who received teach-back education plus zinc had better asthma knowledge, medication use, and symptom control at one month; immunological markers and time to symptom relief improved in both groups.

Trust comment: Randomized pediatric study but zinc was given together with teach-back education so effects are confounded; moderate sample and short follow-up.

Study Details

PMID:40387134
Participants:81
Impact:increased (significantly higher in observation group at 1 month)
Trust score:3/5

immunological levels

1 evidences

Children with asthma who received teach-back education plus zinc had better asthma knowledge, medication use, and symptom control at one month; immunological markers and time to symptom relief improved in both groups.

Trust comment: Randomized pediatric study but zinc was given together with teach-back education so effects are confounded; moderate sample and short follow-up.

Study Details

PMID:40387134
Participants:81
Impact:improved in both groups (significant)
Trust score:3/5

body fat weight

1 evidences

In hemodialysis patients with zinc deficiency, one year of zinc supplementation was associated with increases in body fat weight; serum zinc correlated positively with fat mass.

Trust comment: Open-label RCT in a specific patient group with small sample size; plausible finding but limited generalizability.

Study Details

PMID:39400501
Participants:48
Impact:increased with 1-year zinc supplementation (p < 0.05)
Trust score:3/5

nonfat tissue weight

1 evidences

In hemodialysis patients with zinc deficiency, one year of zinc supplementation was associated with increases in body fat weight; serum zinc correlated positively with fat mass.

Trust comment: Open-label RCT in a specific patient group with small sample size; plausible finding but limited generalizability.

Study Details

PMID:39400501
Participants:48
Impact:no significant correlation with serum zinc
Trust score:3/5

antibiotic/antidiarrheal use

1 evidences

In young children with acute watery diarrhea, zinc (20 mg daily for 14 days) plus ORS had high adherence, did not reduce ORS use, and modestly reduced use of antibiotics/antidiarrheals.

Trust comment: Large multicenter randomized trial with low loss to follow-up and clear outcomes, high confidence in results.

Study Details

PMID:16540790
Participants:2002
Impact:decreased by 3.8% absolute (95% CI 1.7–5.9)
Trust score:5/5

adherence to zinc

1 evidences

In young children with acute watery diarrhea, zinc (20 mg daily for 14 days) plus ORS had high adherence, did not reduce ORS use, and modestly reduced use of antibiotics/antidiarrheals.

Trust comment: Large multicenter randomized trial with low loss to follow-up and clear outcomes, high confidence in results.

Study Details

PMID:16540790
Participants:2002
Impact:83.8% overall (95% CI 81–86)
Trust score:5/5

zinc retention (hospital)

1 evidences

In preterm infants, in-hospital supplemental zinc increased zinc retention during hospitalization but did not raise hair zinc at 6–12 months; growth remained within expected ranges for mother's-milk-fed infants.

Trust comment: Small randomized study with objective measures but limited sample size and mixed feeding groups reduce generalizability.

Study Details

PMID:10213296
Participants:37
Impact:increased with multi-nutrient fortifier containing zinc (significant)
Trust score:3/5

hair zinc concentrations at 6 and 12 months

1 evidences

In preterm infants, in-hospital supplemental zinc increased zinc retention during hospitalization but did not raise hair zinc at 6–12 months; growth remained within expected ranges for mother's-milk-fed infants.

Trust comment: Small randomized study with objective measures but limited sample size and mixed feeding groups reduce generalizability.

Study Details

PMID:10213296
Participants:37
Impact:no sustained increase from in-hospital supplemental zinc
Trust score:3/5

growth (weight/length/head circumference)

1 evidences

In preterm infants, in-hospital supplemental zinc increased zinc retention during hospitalization but did not raise hair zinc at 6–12 months; growth remained within expected ranges for mother's-milk-fed infants.

Trust comment: Small randomized study with objective measures but limited sample size and mixed feeding groups reduce generalizability.

Study Details

PMID:10213296
Participants:37
Impact:adequate (within WHO reference ranges)
Trust score:3/5

malaria episodes per child

1 evidences

Children receiving combined vitamin A and zinc had fewer malaria and fever episodes, lower diarrhea incidence, and reduced anemia compared with placebo over six months.

Trust comment: Randomized double-blind trial with meaningful clinical outcomes, though baseline imbalances and combined supplementation (vitamin A + zinc) limit attribution to zinc alone.

Study Details

PMID:18237394
Participants:148
Impact:decreased (mean 1.5 to 1.0 per child, p = 0.029)
Trust score:4/5

fever episodes per child

1 evidences

Children receiving combined vitamin A and zinc had fewer malaria and fever episodes, lower diarrhea incidence, and reduced anemia compared with placebo over six months.

Trust comment: Randomized double-blind trial with meaningful clinical outcomes, though baseline imbalances and combined supplementation (vitamin A + zinc) limit attribution to zinc alone.

Study Details

PMID:18237394
Participants:148
Impact:decreased (mean 2.04 to 1.63, p = 0.038)
Trust score:4/5

days of oral antibiotics

1 evidences

In this double-blind pilot RCT in children with cystic fibrosis, 30 mg/day zinc for one year reduced days on oral antibiotics, especially in children with low baseline plasma zinc; modest effects on cytokines were observed.

Trust comment: Double-blind RCT design but small pilot sample limits precision and generalizability; subgroup effects plausible.

Study Details

PMID:18214943
Participants:26
Impact:decreased in zinc group (p = 0.05)
Trust score:3/5

effect in low baseline plasma zinc subgroup

1 evidences

In this double-blind pilot RCT in children with cystic fibrosis, 30 mg/day zinc for one year reduced days on oral antibiotics, especially in children with low baseline plasma zinc; modest effects on cytokines were observed.

Trust comment: Double-blind RCT design but small pilot sample limits precision and generalizability; subgroup effects plausible.

Study Details

PMID:18214943
Participants:26
Impact:greater reduction in antibiotic days (p = 0.02)
Trust score:3/5

inflammatory cytokines (IL-6, IL-8) and IL-2 generation

1 evidences

In this double-blind pilot RCT in children with cystic fibrosis, 30 mg/day zinc for one year reduced days on oral antibiotics, especially in children with low baseline plasma zinc; modest effects on cytokines were observed.

Trust comment: Double-blind RCT design but small pilot sample limits precision and generalizability; subgroup effects plausible.

Study Details

PMID:18214943
Participants:26
Impact:marginal reduction in IL-6/IL-8 and increased IL-2 generation (trend)
Trust score:3/5

height Z-score

1 evidences

30 short-statured children received 1 year of iron+zinc, zinc alone, or placebo; iron+zinc improved growth; zinc alone helped only when iron stores (ferritin) were adequate.

Trust comment: Small controlled supplementation study with objective growth measures but limited sample size.

Study Details

PMID:10445218
Participants:30
Impact:+1.58 Z-score (median increase from −2.22 to −0.64) with iron+zinc
Trust score:3/5

growth response to zinc alone

1 evidences

30 short-statured children received 1 year of iron+zinc, zinc alone, or placebo; iron+zinc improved growth; zinc alone helped only when iron stores (ferritin) were adequate.

Trust comment: Small controlled supplementation study with objective growth measures but limited sample size.

Study Details

PMID:10445218
Participants:30
Impact:improved only in children with ferritin >20 ng/L
Trust score:3/5

Relapse prediction score (RPS total)

1 evidences

Randomized single-blind trial in patients on methadone: 12 mg/day zinc for 3 months reduced relapse-prediction measures and improved mental health scores versus control.

Trust comment: Randomized single-blind clinical trial with validated scales and 68 completers but limited blinding and no placebo.

Study Details

PMID:36609286
Participants:68
Impact:≈−5.3 points relative to control (smaller worsening vs control), intergroup p=0.002
Trust score:4/5

DASS-21 total score

1 evidences

Randomized single-blind trial in patients on methadone: 12 mg/day zinc for 3 months reduced relapse-prediction measures and improved mental health scores versus control.

Trust comment: Randomized single-blind clinical trial with validated scales and 68 completers but limited blinding and no placebo.

Study Details

PMID:36609286
Participants:68
Impact:−12.5 points (80.79 → 68.32; ≈−15%) in intervention group over 3 months
Trust score:4/5

Anxiety subscore (DASS)

1 evidences

Randomized single-blind trial in patients on methadone: 12 mg/day zinc for 3 months reduced relapse-prediction measures and improved mental health scores versus control.

Trust comment: Randomized single-blind clinical trial with validated scales and 68 completers but limited blinding and no placebo.

Study Details

PMID:36609286
Participants:68
Impact:−5.26 points (26.64 → 21.38; ≈−19.7%)
Trust score:4/5

Plasma HIV-1 viral load

1 evidences

Double-blind RCT in 96 HIV-1 infected children; 10 mg/day zinc for 6 months did not increase HIV viral load and reduced watery diarrhoea visits.

Trust comment: Double-blind, randomized, placebo-controlled trial with clear primary outcome and adequate sample size for safety endpoints.

Study Details

PMID:16310552
Participants:96
Impact:no change (mean log10 VL 5.4 vs 5.4; difference 0.0002) at 6 months
Trust score:5/5

Watery diarrhoea incidence

1 evidences

Double-blind RCT in 96 HIV-1 infected children; 10 mg/day zinc for 6 months did not increase HIV viral load and reduced watery diarrhoea visits.

Trust comment: Double-blind, randomized, placebo-controlled trial with clear primary outcome and adequate sample size for safety endpoints.

Study Details

PMID:16310552
Participants:96
Impact:7.4% of clinic visits vs 14.5% (47% relative reduction), p=0.001
Trust score:5/5

CD4%

2 evidences

Double-blind RCT in 96 HIV-1 infected children; 10 mg/day zinc for 6 months did not increase HIV viral load and reduced watery diarrhoea visits.

Trust comment: Double-blind, randomized, placebo-controlled trial with clear primary outcome and adequate sample size for safety endpoints.

Study Details

PMID:16310552
Participants:96
Impact:no significant change between groups
Trust score:5/5

In HIV-infected children on ART, 20 mg zinc daily for 24 weeks did not significantly change CD4% or viral load compared with placebo.

Trust comment: Randomized double-blind placebo-controlled trial but small sample size and limited power to detect modest effects.

Study Details

PMID:24798767
Participants:49
Impact:no statistically significant difference at 12 or 24 weeks (median rise to 24.5% vs 22%; P=0.3 at 24 wk)
Trust score:4/5

Episodes of acute lower respiratory infection (ALRI)

1 evidences

Randomized double-blind trial in children <5 with acute lower respiratory infection; 10 mg/day zinc for 60 days reduced respiratory morbidity and sped recovery.

Trust comment: Randomized double-blind controlled trial with clinical endpoints; moderate sample size and single-population setting.

Study Details

PMID:22981241
Participants:96
Impact:20.8% (zinc) vs 45.8% (placebo); absolute reduction 25.0 percentage points, p=0.009
Trust score:4/5

Severe ALRI

1 evidences

Randomized double-blind trial in children <5 with acute lower respiratory infection; 10 mg/day zinc for 60 days reduced respiratory morbidity and sped recovery.

Trust comment: Randomized double-blind controlled trial with clinical endpoints; moderate sample size and single-population setting.

Study Details

PMID:22981241
Participants:96
Impact:21.7% (zinc) vs 58.3% (placebo); absolute reduction 36.6 percentage points, p<0.001
Trust score:4/5

Recovery time

1 evidences

Randomized double-blind trial in children <5 with acute lower respiratory infection; 10 mg/day zinc for 60 days reduced respiratory morbidity and sped recovery.

Trust comment: Randomized double-blind controlled trial with clinical endpoints; moderate sample size and single-population setting.

Study Details

PMID:22981241
Participants:96
Impact:shorter median recovery time in zinc group (p<0.001)
Trust score:4/5

Plaque index

5 evidences

Randomized double-blind trial (92 completers) found the amine+zinc+lactate+fluoride toothpaste significantly reduced gingivitis and plaque versus a fluoride-only control at 3 and 6 months.

Trust comment: Randomized, double-blind single-site trial with appropriate endpoints and statistics, though single-site limits generalizability.

Study Details

PMID:39910536
Participants:92
Impact:baseline-adjusted improvement vs control: 29.1% at 6 months (p<0.001)
Trust score:4/5

Using a zinc+arginine toothpaste twice daily for 6 months reduced dental plaque and gingivitis more than a regular fluoride toothpaste.

Trust comment: Randomized double-blind clinical trial with 100 enrolled and 96 completers showing consistent, statistically significant effects, though industry product involvement noted.

Study Details

PMID:30620869
Participants:96
Impact:-30.1% (6 months vs control)
Trust score:4/5

Adding a dentifrice and rinse containing sanguinaria extract and zinc chloride to initial periodontal therapy provided no additional short-term benefit over placebo.

Trust comment: Randomized double-blind trial but small sample size limits power to detect small effects; zinc present as part of product rather than isolated intervention.

Study Details

PMID:9078647
Participants:34
Impact:no difference between groups
Trust score:3/5

A mouthwash containing an amine compound + zinc lactate + fluoride reduced gum inflammation and dental plaque more than a non‑active control over 6 months.

Trust comment: Well‑conducted triple‑blind RCT with per‑protocol analysis (78 completers); industry sponsorship may introduce bias.

Study Details

PMID:38217757
Participants:78
Impact:-27.7% (AZF vs control) at 6 months
Trust score:4/5

Double-blind randomized trial of 15 mg/day zinc (5 days/week) for 10 weeks in schoolchildren showed plaque index improved with zinc; gingival index improved in both groups.

Trust comment: Double-blind randomized trial with objective oral indices but modest sample size and short duration.

Study Details

PMID:20112596
Participants:68
Impact:more children had decreased plaque in zinc group (18 decreased vs 6 increased; p=0.02)
Trust score:3/5

gingival index

5 evidences

Using a zinc+arginine toothpaste twice daily for 6 months reduced dental plaque and gingivitis more than a regular fluoride toothpaste.

Trust comment: Randomized double-blind clinical trial with 100 enrolled and 96 completers showing consistent, statistically significant effects, though industry product involvement noted.

Study Details

PMID:30620869
Participants:96
Impact:-26.3% (6 months vs control)
Trust score:4/5

Double-blind randomized trial of 15 mg/day zinc (5 days/week) for 10 weeks in schoolchildren showed plaque index improved with zinc; gingival index improved in both groups.

Trust comment: Double-blind randomized trial with objective oral indices but modest sample size and short duration.

Study Details

PMID:20112596
Participants:68
Impact:improved in both zinc and placebo groups (no zinc-specific effect)
Trust score:3/5

Randomized double-blind trial (92 completers) found the amine+zinc+lactate+fluoride toothpaste significantly reduced gingivitis and plaque versus a fluoride-only control at 3 and 6 months.

Trust comment: Randomized, double-blind single-site trial with appropriate endpoints and statistics, though single-site limits generalizability.

Study Details

PMID:39910536
Participants:92
Impact:baseline-adjusted improvement vs control: 27.8% at 6 months (p<0.001)
Trust score:4/5

A mouthwash containing an amine compound + zinc lactate + fluoride reduced gum inflammation and dental plaque more than a non‑active control over 6 months.

Trust comment: Well‑conducted triple‑blind RCT with per‑protocol analysis (78 completers); industry sponsorship may introduce bias.

Study Details

PMID:38217757
Participants:78
Impact:-30.7% (AZF vs control) at 6 months
Trust score:4/5

Brushing with an herbal toothpaste containing zinc for 6 months reduced plaque, gingival inflammation, and bleeding more than a fluoride-only toothpaste.

Trust comment: Randomized clinical trial with reasonable completion rate and clear reported outcomes, though formulations included multiple herbal ingredients alongside zinc.

Study Details

PMID:33866666
Participants:150
Impact:-25.6%
Trust score:4/5

days of coughing

1 evidences

Zinc lozenges shortened the duration of common cold symptoms but caused more bad taste and nausea.

Trust comment: Randomized, double-blind, placebo-controlled RCT with objective median symptom durations but outcomes largely patient-reported; moderate sample size.

Study Details

PMID:8678384
Participants:100
Impact:median −2.5 days (2.0 vs 4.5 days)
Trust score:4/5

overall adverse effects (side effects)

1 evidences

Zinc lozenges shortened the duration of common cold symptoms but caused more bad taste and nausea.

Trust comment: Randomized, double-blind, placebo-controlled RCT with objective median symptom durations but outcomes largely patient-reported; moderate sample size.

Study Details

PMID:8678384
Participants:100
Impact:+28 percentage points (90% vs 62%); bad taste +50 pp (80% vs 30%); nausea +16 pp (20% vs 4%)
Trust score:4/5

spatial working memory

1 evidences

Daily 15–30 mg zinc produced limited, inconsistent cognitive effects: brief improvement in one spatial working memory measure at 3 months and a detriment on one attention measure.

Trust comment: Large randomized double-blind placebo-controlled trial, but effects were small, inconsistent and transient across measured cognitive tasks.

Study Details

PMID:17010236
Participants:387
Impact:statistically improved at 3 months (15 and 30 mg/d; magnitude not reported)
Trust score:3/5

attention

1 evidences

Daily 15–30 mg zinc produced limited, inconsistent cognitive effects: brief improvement in one spatial working memory measure at 3 months and a detriment on one attention measure.

Trust comment: Large randomized double-blind placebo-controlled trial, but effects were small, inconsistent and transient across measured cognitive tasks.

Study Details

PMID:17010236
Participants:387
Impact:detrimental effect for 15 mg/d at 3 months (one measure)
Trust score:3/5

body weight gain

1 evidences

In 12–24-month-old children, the small zinc-only arm showed a significant increase in TGF-β1 and greater body-weight gain over 90 days; probiotic and combined arms affected sIgA and cytokine correlations.

Trust comment: Randomized placebo-controlled trial but very small zinc arm (n=8) limits precision and generalizability.

Study Details

PMID:30694099
Participants:38
Impact:significant increase in zinc group (post hoc)
Trust score:3/5

viral load

1 evidences

In HIV-infected children on ART, 20 mg zinc daily for 24 weeks did not significantly change CD4% or viral load compared with placebo.

Trust comment: Randomized double-blind placebo-controlled trial but small sample size and limited power to detect modest effects.

Study Details

PMID:24798767
Participants:49
Impact:similar log reductions in both groups (no significant difference)
Trust score:4/5

days of antibiotic use over 12 months

1 evidences

Daily 30 mg zinc for 12 months did not reduce antibiotic use, change lung function, or alter Pseudomonas colonization in children with cystic fibrosis.

Trust comment: Double-blind randomized trial but small sample size limits ability to detect modest clinical benefits.

Study Details

PMID:26443019
Participants:37
Impact:no significant difference (median 42 vs 38 days; P=0.79)
Trust score:4/5

FEV1 (percent predicted)

1 evidences

Daily 30 mg zinc for 12 months did not reduce antibiotic use, change lung function, or alter Pseudomonas colonization in children with cystic fibrosis.

Trust comment: Double-blind randomized trial but small sample size limits ability to detect modest clinical benefits.

Study Details

PMID:26443019
Participants:37
Impact:no significant difference at 12 months (P=0.44)
Trust score:4/5

Pseudomonas colonization

1 evidences

Daily 30 mg zinc for 12 months did not reduce antibiotic use, change lung function, or alter Pseudomonas colonization in children with cystic fibrosis.

Trust comment: Double-blind randomized trial but small sample size limits ability to detect modest clinical benefits.

Study Details

PMID:26443019
Participants:37
Impact:no significant difference between groups over time
Trust score:4/5

dentin hypersensitivity (VAS after air-blast)

1 evidences

Topical zinc-doped nanoparticles applied to cervical dentin progressively and significantly reduced dentin hypersensitivity and eliminated sensitivity by day 21 for tested measures.

Trust comment: Randomized double-blind placebo-controlled clinical trial with small sample and validated pain scales, showing consistent positive effects for topical application.

Study Details

PMID:40517062
Participants:60
Impact:progressive significant reduction and complete disappearance at 21 days
Trust score:4/5

Schiff air index

1 evidences

Topical zinc-doped nanoparticles applied to cervical dentin progressively and significantly reduced dentin hypersensitivity and eliminated sensitivity by day 21 for tested measures.

Trust comment: Randomized double-blind placebo-controlled clinical trial with small sample and validated pain scales, showing consistent positive effects for topical application.

Study Details

PMID:40517062
Participants:60
Impact:progressive significant reduction and complete disappearance at 21 days
Trust score:4/5

dentin hypersensitivity (VAS after percussion)

1 evidences

Topical zinc-doped nanoparticles applied to cervical dentin progressively and significantly reduced dentin hypersensitivity and eliminated sensitivity by day 21 for tested measures.

Trust comment: Randomized double-blind placebo-controlled clinical trial with small sample and validated pain scales, showing consistent positive effects for topical application.

Study Details

PMID:40517062
Participants:60
Impact:significant reduction immediately and at day 14 (less consistent by day 21)
Trust score:4/5

rate of diarrhea termination

1 evidences

Large randomized trial in Nepal showed zinc reduced duration and risk of prolonged acute diarrhea in young children.

Trust comment: Large randomized placebo-controlled trial with robust sample size and clear effect estimates.

Study Details

PMID:11986453
Participants:1792
Impact:+26% relative hazard (zinc vs placebo)
Trust score:5/5

risk of prolonged diarrhea (>7 days)

1 evidences

Large randomized trial in Nepal showed zinc reduced duration and risk of prolonged acute diarrhea in young children.

Trust comment: Large randomized placebo-controlled trial with robust sample size and clear effect estimates.

Study Details

PMID:11986453
Participants:1792
Impact:-43% to -47% relative risk (RR ≈0.53–0.57)
Trust score:5/5

vomiting/regurgitation after administration

1 evidences

Large randomized trial in Nepal showed zinc reduced duration and risk of prolonged acute diarrhea in young children.

Trust comment: Large randomized placebo-controlled trial with robust sample size and clear effect estimates.

Study Details

PMID:11986453
Participants:1792
Impact:increased (regurgitation ~5% with zinc vs 1.3% placebo)
Trust score:5/5

NIH Stroke Scale (NIHSS) improvement

1 evidences

Small randomized trial in subacute stroke patients with low zinc intake; normalizing zinc intake modestly improved neurological scores.

Trust comment: Randomized but very small sample (n=26), so effects are imprecise and need replication.

Study Details

PMID:19761652
Participants:26
Impact:greater improvement in zinc group: -4.7 vs -3.3 points (difference -1.4 points, P < 0.02)
Trust score:3/5

febrile seizure recurrence

1 evidences

Randomized trial in children with first simple febrile seizure showed zinc supplementation reduced seizure recurrence over one year.

Trust comment: Randomized clinical trial with clear outcome and statistically significant result though moderate sample size.

Study Details

PMID:26429655
Participants:100
Impact:decreased from 38% (control) to 22% (zinc); absolute reduction 16 percentage points (P = 0.03)
Trust score:4/5

case fatality (mortality)

1 evidences

Randomized double-blind trial in Ugandan children with severe pneumonia found zinc adjunct did not speed clinical normalization but reduced mortality.

Trust comment: Large, well-conducted randomized double-blind trial with a robust mortality finding (secondary outcome) though primary endpoints were null.

Study Details

PMID:22316073
Participants:352
Impact:reduced from 11.9% (placebo) to 4.0% (zinc); RR 0.33
Trust score:4/5

time to normalization of respiratory rate

1 evidences

Randomized double-blind trial in Ugandan children with severe pneumonia found zinc adjunct did not speed clinical normalization but reduced mortality.

Trust comment: Large, well-conducted randomized double-blind trial with a robust mortality finding (secondary outcome) though primary endpoints were null.

Study Details

PMID:22316073
Participants:352
Impact:no significant change (median 96 h zinc vs 86 h placebo; P=0.306)
Trust score:4/5

time to normalization of temperature

1 evidences

Randomized double-blind trial in Ugandan children with severe pneumonia found zinc adjunct did not speed clinical normalization but reduced mortality.

Trust comment: Large, well-conducted randomized double-blind trial with a robust mortality finding (secondary outcome) though primary endpoints were null.

Study Details

PMID:22316073
Participants:352
Impact:no significant change (median 18 h both groups; P=0.897)
Trust score:4/5

apoprotein A-I

1 evidences

Randomized double-blind trial of combined zinc plus vitamin A in type I diabetes improved apolipoprotein profile (A-I up, B down) over 12 weeks.

Trust comment: Randomized trial but intervention combined zinc with vitamin A, so effects cannot be attributed to zinc alone; small sample size.

Study Details

PMID:20151940
Participants:48
Impact:significant increase (P < 0.0001)
Trust score:3/5

apoprotein B

1 evidences

Randomized double-blind trial of combined zinc plus vitamin A in type I diabetes improved apolipoprotein profile (A-I up, B down) over 12 weeks.

Trust comment: Randomized trial but intervention combined zinc with vitamin A, so effects cannot be attributed to zinc alone; small sample size.

Study Details

PMID:20151940
Participants:48
Impact:significant decrease (P < 0.0001)
Trust score:3/5

apoprotein B/apoprotein A-I ratio

1 evidences

Randomized double-blind trial of combined zinc plus vitamin A in type I diabetes improved apolipoprotein profile (A-I up, B down) over 12 weeks.

Trust comment: Randomized trial but intervention combined zinc with vitamin A, so effects cannot be attributed to zinc alone; small sample size.

Study Details

PMID:20151940
Participants:48
Impact:significant decrease (P < 0.0001 vs baseline; P = 0.02 vs control)
Trust score:3/5

stool frequency

2 evidences

Zinc given for acute diarrhoea reduced stool frequency and improved recovery; suspension form had better outcomes and compliance than tablets.

Trust comment: Cohort study in an emergency field setting with 200 children; non-randomized allocation limits causal inference.

Study Details

PMID:21205556
Participants:200
Impact:reduced (significant on Day 2 and Day 3)
Trust score:3/5

Zinc did not reduce duration or severity of acute diarrhea in young infants.

Trust comment: Large randomized placebo-controlled trial in infants with clear outcome measures and analyses.

Study Details

PMID:16954960
Participants:1110
Impact:no difference
Trust score:4/5

vomiting rate

1 evidences

Zinc did not reduce duration or severity of acute diarrhea in young infants.

Trust comment: Large randomized placebo-controlled trial in infants with clear outcome measures and analyses.

Study Details

PMID:16954960
Participants:1110
Impact:no difference
Trust score:4/5

CD4+DR+ T-cells

1 evidences

Zinc supplementation increased specific T‑cell subsets in older adults.

Trust comment: Double-blind randomized trial with immunologic endpoints and statistically significant results.

Study Details

PMID:9434661
Participants:118
Impact:increased (P = 0.016)
Trust score:4/5

cytotoxic T-lymphocytes

1 evidences

Zinc supplementation increased specific T‑cell subsets in older adults.

Trust comment: Double-blind randomized trial with immunologic endpoints and statistically significant results.

Study Details

PMID:9434661
Participants:118
Impact:increased (P = 0.005)
Trust score:4/5

physical component score (PCS)

1 evidences

Zinc improved physical quality of life, lowered ammonia and encephalopathy grade in cirrhotic patients.

Trust comment: Randomized clinical trial in patients with cirrhosis reporting clinical, laboratory, and functional outcomes with multivariate analysis.

Study Details

PMID:20822500
Participants:79
Impact:improved (P = 0.04)
Trust score:4/5

hepatic encephalopathy grade

1 evidences

Zinc improved physical quality of life, lowered ammonia and encephalopathy grade in cirrhotic patients.

Trust comment: Randomized clinical trial in patients with cirrhosis reporting clinical, laboratory, and functional outcomes with multivariate analysis.

Study Details

PMID:20822500
Participants:79
Impact:decreased (P = 0.03)
Trust score:4/5

blood ammonia

1 evidences

Zinc improved physical quality of life, lowered ammonia and encephalopathy grade in cirrhotic patients.

Trust comment: Randomized clinical trial in patients with cirrhosis reporting clinical, laboratory, and functional outcomes with multivariate analysis.

Study Details

PMID:20822500
Participants:79
Impact:decreased (P = 0.01)
Trust score:4/5

Child-Pugh score

1 evidences

Zinc improved physical quality of life, lowered ammonia and encephalopathy grade in cirrhotic patients.

Trust comment: Randomized clinical trial in patients with cirrhosis reporting clinical, laboratory, and functional outcomes with multivariate analysis.

Study Details

PMID:20822500
Participants:79
Impact:improved (P = 0.04)
Trust score:4/5

neuropsychological tests

1 evidences

Zinc improved physical quality of life, lowered ammonia and encephalopathy grade in cirrhotic patients.

Trust comment: Randomized clinical trial in patients with cirrhosis reporting clinical, laboratory, and functional outcomes with multivariate analysis.

Study Details

PMID:20822500
Participants:79
Impact:improved (P = 0.02)
Trust score:4/5

SOFA score

1 evidences

Zinc raised plasma zinc, improved organ-failure and outcome scores, reduced inflammation, and shortened hospital stay in severe head trauma patients.

Trust comment: Double-blind RCT with clinically relevant endpoints and significant changes in several outcomes, though sample size is modest.

Study Details

PMID:28467150
Participants:100
Impact:improved by day 16 (p < 0.05)
Trust score:4/5

Glasgow Outcome Score (GOS)

1 evidences

Zinc raised plasma zinc, improved organ-failure and outcome scores, reduced inflammation, and shortened hospital stay in severe head trauma patients.

Trust comment: Double-blind RCT with clinically relevant endpoints and significant changes in several outcomes, though sample size is modest.

Study Details

PMID:28467150
Participants:100
Impact:improved by day 16 (p < 0.05)
Trust score:4/5

inflammatory markers (CRP, ESR, WBC)

1 evidences

Zinc raised plasma zinc, improved organ-failure and outcome scores, reduced inflammation, and shortened hospital stay in severe head trauma patients.

Trust comment: Double-blind RCT with clinically relevant endpoints and significant changes in several outcomes, though sample size is modest.

Study Details

PMID:28467150
Participants:100
Impact:improved by day 16 (p < 0.05)
Trust score:4/5

length of stay

1 evidences

Zinc raised plasma zinc, improved organ-failure and outcome scores, reduced inflammation, and shortened hospital stay in severe head trauma patients.

Trust comment: Double-blind RCT with clinically relevant endpoints and significant changes in several outcomes, though sample size is modest.

Study Details

PMID:28467150
Participants:100
Impact:shorter (52 vs 65 days, p = 0.043)
Trust score:4/5

peripheral blood transcriptome

1 evidences

In Bangladeshi infants, zinc (tablets or MNPs) did not change peripheral blood gene expression or most cytokines; IL-17A was higher with zinc.

Trust comment: Well-controlled sub-study of an RCT using RNA-seq and ultrasensitive cytokine assays with clear negative and limited positive findings.

Study Details

PMID:34684517
Participants:100
Impact:no change
Trust score:4/5

serum cytokines (IFN-γ, IL-6, IL-10, IL-12p70, TNFα)

1 evidences

In Bangladeshi infants, zinc (tablets or MNPs) did not change peripheral blood gene expression or most cytokines; IL-17A was higher with zinc.

Trust comment: Well-controlled sub-study of an RCT using RNA-seq and ultrasensitive cytokine assays with clear negative and limited positive findings.

Study Details

PMID:34684517
Participants:100
Impact:no change
Trust score:4/5

IL-17A

1 evidences

In Bangladeshi infants, zinc (tablets or MNPs) did not change peripheral blood gene expression or most cytokines; IL-17A was higher with zinc.

Trust comment: Well-controlled sub-study of an RCT using RNA-seq and ultrasensitive cytokine assays with clear negative and limited positive findings.

Study Details

PMID:34684517
Participants:100
Impact:increased (higher than placebo at endline)
Trust score:4/5

energy apparent absorption

1 evidences

Crossover study in formula-fed infants comparing higher vs lower dietary fiber in weaning cereals; measured stool characteristics and mineral (including zinc) absorption using stable isotopes.

Trust comment: Human crossover study with isotope measurements of zinc absorption in infants; subgroup sample for isotope measures limited but methods are direct and appropriate.

Study Details

PMID:8642490
Participants:57
Impact:95.3% vs 95.7% (no significant difference)
Trust score:4/5

nitrogen apparent absorption

1 evidences

Crossover study in formula-fed infants comparing higher vs lower dietary fiber in weaning cereals; measured stool characteristics and mineral (including zinc) absorption using stable isotopes.

Trust comment: Human crossover study with isotope measurements of zinc absorption in infants; subgroup sample for isotope measures limited but methods are direct and appropriate.

Study Details

PMID:8642490
Participants:57
Impact:92.6% vs 93.0% (no significant difference)
Trust score:4/5

head circumference (children 1–5 y)

1 evidences

Cluster RCT providing zinc-biofortified or control wheat flour to households for 25 weeks; primary outcome was plasma zinc (reported elsewhere); secondary outcomes here included growth, morbidity and lung function.

Trust comment: Large double-blind, cluster-randomised trial with objective anthropometry and repeated morbidity surveillance; secondary outcomes may be underpowered and zinc differential was modest.

Study Details

PMID:40218895
Participants:1034
Impact:β = +0.432 cm (endline); HCZ β = +0.367 (endline) — significant increase
Trust score:5/5

respiratory tract infection incidence (selected timepoints)

1 evidences

Cluster RCT providing zinc-biofortified or control wheat flour to households for 25 weeks; primary outcome was plasma zinc (reported elsewhere); secondary outcomes here included growth, morbidity and lung function.

Trust comment: Large double-blind, cluster-randomised trial with objective anthropometry and repeated morbidity surveillance; secondary outcomes may be underpowered and zinc differential was modest.

Study Details

PMID:40218895
Participants:1034
Impact:Adolescents week26: 14.5%→6.1% (−8.4 pp, p=0.014); Children week26: 27.4%→17.6% (−9.8 pp, p=0.036) (transient, not significant over full follow-up)
Trust score:5/5

height/weight/BMI and lung function

1 evidences

Cluster RCT providing zinc-biofortified or control wheat flour to households for 25 weeks; primary outcome was plasma zinc (reported elsewhere); secondary outcomes here included growth, morbidity and lung function.

Trust comment: Large double-blind, cluster-randomised trial with objective anthropometry and repeated morbidity surveillance; secondary outcomes may be underpowered and zinc differential was modest.

Study Details

PMID:40218895
Participants:1034
Impact:No significant change between arms over study period
Trust score:5/5

vomiting during diarrhea (overall)

1 evidences

Secondary analysis of a large randomized trial in children with acute diarrhea assessing factors associated with vomiting; evaluated effects of zinc dose and clinical/demographic risk factors.

Trust comment: Large (n=4500) randomized double-blind trial dataset used for robust secondary analyses identifying clinically relevant risk modifiers for vomiting with zinc therapy.

Study Details

PMID:39806793
Participants:4500
Impact:1203/4500 (26.7%) had any vomiting
Trust score:5/5

risk factors for vomiting

1 evidences

Secondary analysis of a large randomized trial in children with acute diarrhea assessing factors associated with vomiting; evaluated effects of zinc dose and clinical/demographic risk factors.

Trust comment: Large (n=4500) randomized double-blind trial dataset used for robust secondary analyses identifying clinically relevant risk modifiers for vomiting with zinc therapy.

Study Details

PMID:39806793
Participants:4500
Impact:Dehydration RR 1.45 (95% CI 1.10–1.92); Underweight RR 1.22 (1.05–1.41); Rotavirus vaccine RR 1.89 (1.69–2.12); Household wealth > median RR 1.17 (1.07–1.29)
Trust score:5/5

zinc dose effect on vomiting

1 evidences

Secondary analysis of a large randomized trial in children with acute diarrhea assessing factors associated with vomiting; evaluated effects of zinc dose and clinical/demographic risk factors.

Trust comment: Large (n=4500) randomized double-blind trial dataset used for robust secondary analyses identifying clinically relevant risk modifiers for vomiting with zinc therapy.

Study Details

PMID:39806793
Participants:4500
Impact:Lower zinc doses (5 or 10 mg vs 20 mg) associated with lower vomiting rates (dose-dependent increase with higher dose)
Trust score:5/5

plantar wart complete clearance rate

1 evidences

In 105 patients with plantar warts, intralesional vitamin D3 produced complete response in 62.9% of patients and was more effective than saline with mostly mild injection pain.

Trust comment: Randomized clinical trial with adequate sample (35 per arm) showing clear efficacy but notable pain adverse events.

Study Details

PMID:32162438
Participants:105
Impact:71.4% complete response (vs 40% saline; +31.4 percentage points vs saline)
Trust score:4/5

injection pain severity

1 evidences

In 105 patients with plantar warts, intralesional vitamin D3 produced complete response in 62.9% of patients and was more effective than saline with mostly mild injection pain.

Trust comment: Randomized clinical trial with adequate sample (35 per arm) showing clear efficacy but notable pain adverse events.

Study Details

PMID:32162438
Participants:105
Impact:higher (48.6% severe pain)
Trust score:4/5

prolonged diarrheal episodes (>=2 days)

1 evidences

Weekly zinc supplementation in young children reduced diarrheal illness and was feasible to deliver in the community.

Trust comment: Large randomized double-blind community trial with extensive follow-up and good operational data supports high trust.

Study Details

PMID:17414392
Participants:1712
Impact:decreased (fewer prolonged episodes)
Trust score:5/5

program adherence

1 evidences

Weekly zinc supplementation in young children reduced diarrheal illness and was feasible to deliver in the community.

Trust comment: Large randomized double-blind community trial with extensive follow-up and good operational data supports high trust.

Study Details

PMID:17414392
Participants:1712
Impact:high (~96% mothers administered weekly; ~85% surveillance coverage)
Trust score:5/5

incidence of infections

2 evidences

Three months of zinc (25 mg thrice daily) in adults with sickle cell disease reduced infections, lowered oxidative stress markers, and reduced proinflammatory cytokine expression.

Trust comment: Small randomized placebo-controlled trial with consistent biomarker changes, but limited size and short duration.

Study Details

PMID:18674741
Participants:36
Impact:decreased in zinc-supplemented group vs placebo
Trust score:3/5

One year of zinc (45 mg/day) reduced infections and some inflammatory and oxidative stress markers in older adults.

Trust comment: Randomized double-blind placebo-controlled trial with relevant biological markers and clinical outcomes, but modest sample size (n=50).

Study Details

PMID:17344507
Participants:50
Impact:decreased (significantly fewer infections vs placebo)
Trust score:4/5

tumor necrosis factor-alpha generation

1 evidences

One year of zinc (45 mg/day) reduced infections and some inflammatory and oxidative stress markers in older adults.

Trust comment: Randomized double-blind placebo-controlled trial with relevant biological markers and clinical outcomes, but modest sample size (n=50).

Study Details

PMID:17344507
Participants:50
Impact:decreased
Trust score:4/5

low serum zinc prevalence

2 evidences

Most critically ill children had low serum zinc early after PICU admission and low zinc was associated with higher frequency of lymphopenia.

Trust comment: Large observational baseline dataset from a multicenter trial; shows association (not causation) between low serum zinc and lymphopenia.

Study Details

PMID:23392368
Participants:280
Impact:83.9% below normal reference range (235 of 280)
Trust score:3/5

Six months of zinc supplementation reduced low serum zinc prevalence; associations between intake and biomarkers were inconsistent and attenuated by fortification.

Trust comment: Large randomized trial but concurrent government milk fortification confounds interpretation of supplementation effects.

Study Details

PMID:23964387
Participants:691
Impact:decreased (1.2% in supplemented vs 4.0% in placebo at 6 months)
Trust score:3/5

low total zinc intake prevalence

1 evidences

Six months of zinc supplementation reduced low serum zinc prevalence; associations between intake and biomarkers were inconsistent and attenuated by fortification.

Trust comment: Large randomized trial but concurrent government milk fortification confounds interpretation of supplementation effects.

Study Details

PMID:23964387
Participants:691
Impact:decreased (0.0% in supplemented vs 34.1% in placebo at 6 months)
Trust score:3/5

mental development (Bayley scores)

1 evidences

Daily low-dose zinc supplementation from 1 to 9 months had no detectable effect on infant cognitive or motor development at 6 or 10 months.

Trust comment: Randomized controlled trial (n=200) with standardized developmental assessments but null results may reflect measurement sensitivity or other nutritional factors.

Study Details

PMID:15121945
Participants:200
Impact:no significant change
Trust score:4/5

motor development (Bayley scores)

1 evidences

Daily low-dose zinc supplementation from 1 to 9 months had no detectable effect on infant cognitive or motor development at 6 or 10 months.

Trust comment: Randomized controlled trial (n=200) with standardized developmental assessments but null results may reflect measurement sensitivity or other nutritional factors.

Study Details

PMID:15121945
Participants:200
Impact:no significant change
Trust score:4/5

erythrocyte zinc concentration

5 evidences

Adding a 25 mg/day zinc supplement during pregnancy increased plasma zinc among women with higher total zinc intake; erythrocyte zinc tracked with habitual dietary intake.

Trust comment: Large randomized double-blind trial with biomarker outcomes, giving reliable evidence on zinc status though pregnancy physiology affects zinc levels.

Study Details

PMID:9366865
Participants:580
Impact:higher in women with higher habitual dietary zinc intake (at randomization and subsequent measures)
Trust score:4/5

Graves' disease patients treated with methimazole were given antioxidant supplements (no zinc in the supplement) and erythrocyte SOD, Cu, Zn and total antioxidant status were followed for 60 days.

Trust comment: Controlled study on humans with moderate sample size; zinc was measured but not supplemented, and exact numeric changes for zinc are not provided in the text.

Study Details

PMID:15899653
Participants:55
Impact:significant between-group difference (supplement vs control) — exact magnitude not reported
Trust score:3/5

ACE inhibitor therapy altered zinc parameters: serum zinc fell and urinary zinc rose during treatment.

Trust comment: Randomized, double-blind comparison of ACE inhibitors in 31 hypertensive patients; small sample but measurements direct and reported with statistics.

Study Details

PMID:8966143
Participants:31
Impact:no change (ZnE unchanged)
Trust score:3/5

Three-month randomized trial of antihypertensive monotherapy showing diuretics, ACE‑inhibitors and calcium‑antagonists altered zinc status (increased zincuria and reduced serum/erythrocyte zinc); not investigating calcium supplementation or calcium outcomes.

Trust comment: Well-characterized prospective trial with careful mineral measurements and dietary control, though allocation details limit generalizability.

Study Details

PMID:30208601
Participants:98
Impact:decreased after diuretics and after Ca-antagonists (significant)
Trust score:4/5

Eight weeks of zinc supplementation in postmenopausal women improved erythrocyte zinc status and was associated with enhanced antioxidant markers.

Trust comment: Double-blind randomized design supports causality but sample size is small and outcomes are biomarker/correlational.

Study Details

PMID:35278643
Participants:51
Impact:increased (status improved after intervention)
Trust score:4/5

plasma zinc concentration at 6 months

1 evidences

Infants exclusively breastfed 4–6 months had slightly higher plasma zinc at 6 months than those breastfed <4 months, with no differences in iron status or anemia.

Trust comment: Large observational trial with substantial sample size and laboratory measures, though observational associations not causal evidence.

Study Details

PMID:19535419
Participants:1040
Impact:higher by 0.4 µmol/L (9.9 vs 9.5 µmol/L, P<0.01)
Trust score:4/5

plasma ferritin (iron status)

1 evidences

Infants exclusively breastfed 4–6 months had slightly higher plasma zinc at 6 months than those breastfed <4 months, with no differences in iron status or anemia.

Trust comment: Large observational trial with substantial sample size and laboratory measures, though observational associations not causal evidence.

Study Details

PMID:19535419
Participants:1040
Impact:no significant difference
Trust score:4/5

hemoglobin / anemia prevalence

2 evidences

Randomized controlled trial in hospitalized adults with HIV comparing standard diet vs standard + 100 g RUTF (provided zinc among other nutrients); final analysis n=37.

Trust comment: Randomized trial but with modest final sample (n=37), notable attrition and hospital deaths; results for body composition and anemia are plausible but zinc outcome null.

Study Details

PMID:26728978
Participants:37
Impact:hemoglobin increased more in RUTF group (+3.33 μg/dL vs +0.82 μg/dL; p=0.004); anemia prevalence fell from 94% to 50% in RUTF group (p=0.003)
Trust score:3/5

Infants exclusively breastfed 4–6 months had slightly higher plasma zinc at 6 months than those breastfed <4 months, with no differences in iron status or anemia.

Trust comment: Large observational trial with substantial sample size and laboratory measures, though observational associations not causal evidence.

Study Details

PMID:19535419
Participants:1040
Impact:no significant difference
Trust score:4/5

weight/length growth at 12 months

1 evidences

Term infants given 5 mg/day zinc showed no growth benefit but had modest improvements in motor quality and fewer infants with low mental/motor scores.

Trust comment: Randomized trial with reasonable follow-up (112 completers); modest sample limits precision for some outcomes.

Study Details

PMID:11174621
Participants:112
Impact:no effect
Trust score:4/5

motor quality factor at 12 months

1 evidences

Term infants given 5 mg/day zinc showed no growth benefit but had modest improvements in motor quality and fewer infants with low mental/motor scores.

Trust comment: Randomized trial with reasonable follow-up (112 completers); modest sample limits precision for some outcomes.

Study Details

PMID:11174621
Participants:112
Impact:higher by ~1.1 points (31.9 vs 30.8, P<0.05); fewer low motor-quality cases at 6 months (2/57 vs 8/52, P=0.02)
Trust score:4/5

mental development index (MDI)

1 evidences

Term infants given 5 mg/day zinc showed no growth benefit but had modest improvements in motor quality and fewer infants with low mental/motor scores.

Trust comment: Randomized trial with reasonable follow-up (112 completers); modest sample limits precision for some outcomes.

Study Details

PMID:11174621
Participants:112
Impact:means similar (90.9 vs 88.9) though fewer infants in supplemented group scored unusually low (reported difference)
Trust score:4/5

peripheral blood leukocyte counts

1 evidences

Healthy men taking 30 mg/day zinc for 14 weeks showed no changes in circulating leukocyte counts, lymphocyte subsets, or copper status.

Trust comment: Controlled supplementation trial but small sample size; measures appropriate and results consistent.

Study Details

PMID:12720590
Participants:38
Impact:no change
Trust score:3/5

lymphocyte subsets (flow cytometry)

1 evidences

Healthy men taking 30 mg/day zinc for 14 weeks showed no changes in circulating leukocyte counts, lymphocyte subsets, or copper status.

Trust comment: Controlled supplementation trial but small sample size; measures appropriate and results consistent.

Study Details

PMID:12720590
Participants:38
Impact:no change
Trust score:3/5

copper status

1 evidences

Healthy men taking 30 mg/day zinc for 14 weeks showed no changes in circulating leukocyte counts, lymphocyte subsets, or copper status.

Trust comment: Controlled supplementation trial but small sample size; measures appropriate and results consistent.

Study Details

PMID:12720590
Participants:38
Impact:no change
Trust score:3/5

urinary arsenic excretion

1 evidences

In arsenic-poisoned patients, spirulina plus zinc increased urinary arsenic excretion early, reduced hair arsenic by ~47%, and improved skin lesions over 16 weeks.

Trust comment: Randomized double-blind trial but small sample and combined spirulina+zinc intervention prevents isolating zinc-specific effects.

Study Details

PMID:16615668
Participants:41
Impact:marked increase at 4 weeks (138 ± 43.6 µg/L) following treatment
Trust score:3/5

hair arsenic content

1 evidences

In arsenic-poisoned patients, spirulina plus zinc increased urinary arsenic excretion early, reduced hair arsenic by ~47%, and improved skin lesions over 16 weeks.

Trust comment: Randomized double-blind trial but small sample and combined spirulina+zinc intervention prevents isolating zinc-specific effects.

Study Details

PMID:16615668
Participants:41
Impact:reduced by 47.1% after treatment
Trust score:3/5

clinical skin scores (melanosis, keratosis)

1 evidences

In arsenic-poisoned patients, spirulina plus zinc increased urinary arsenic excretion early, reduced hair arsenic by ~47%, and improved skin lesions over 16 weeks.

Trust comment: Randomized double-blind trial but small sample and combined spirulina+zinc intervention prevents isolating zinc-specific effects.

Study Details

PMID:16615668
Participants:41
Impact:significant improvement in treated group (keratosis P<0.05; melanosis improved)
Trust score:3/5

diarrhoea severity/incidence

1 evidences

Two-week zinc supplementation raised plasma zinc by day 14 but did not significantly shorten diarrhoea duration or reduce severity or incidence versus control.

Trust comment: Randomized clinical trial with adequate sample but open-label and non-placebo-controlled, limiting clinical inference despite biomarker change.

Study Details

PMID:16354711
Participants:280
Impact:no significant difference between groups
Trust score:3/5

leukocyte MT2A expression

1 evidences

Perioperative zinc plus vitamin E transiently lowered plasma copper on postoperative day 3 and increased leukocyte MT2A expression at days 3 and 21, with no lasting copper depletion.

Trust comment: Randomized add-on trial in surgical patients with clear biomarker endpoints; moderate sample size and relevant measurements support credibility.

Study Details

PMID:38865064
Participants:78
Impact:increased at days 3 and 21 in zinc-vitE group
Trust score:4/5

ceruloplasmin / SOD activity

1 evidences

Perioperative zinc plus vitamin E transiently lowered plasma copper on postoperative day 3 and increased leukocyte MT2A expression at days 3 and 21, with no lasting copper depletion.

Trust comment: Randomized add-on trial in surgical patients with clear biomarker endpoints; moderate sample size and relevant measurements support credibility.

Study Details

PMID:38865064
Participants:78
Impact:no between-group differences
Trust score:4/5

weight gain (nutritional status)

1 evidences

In a double-blind RCT, oral zinc (2 mg/kg/day) did not raise plasma zinc significantly but was associated with improved weight gain and fewer infection episodes during 60 days.

Trust comment: Randomized double-blind placebo-controlled design supports internal validity though sample size is small.

Study Details

PMID:23963274
Participants:38
Impact:positive weight gain observed with zinc
Trust score:4/5

infection episodes

1 evidences

In a double-blind RCT, oral zinc (2 mg/kg/day) did not raise plasma zinc significantly but was associated with improved weight gain and fewer infection episodes during 60 days.

Trust comment: Randomized double-blind placebo-controlled design supports internal validity though sample size is small.

Study Details

PMID:23963274
Participants:38
Impact:significantly reduced number of infections with zinc
Trust score:4/5

low plasma zinc prevalence

1 evidences

Cross-sectional/preintervention data show high prevalence of low plasma zinc and stunting in rural Beninese children, with intake-based risk estimates varying by EAR used.

Trust comment: Large cross-sectional dataset with measured biomarkers; observational design limits causal inference about interventions.

Study Details

PMID:26609168
Participants:598
Impact:45.7% adjusted prevalence of low PZn
Trust score:3/5

stunting (<5 y)

1 evidences

Cross-sectional/preintervention data show high prevalence of low plasma zinc and stunting in rural Beninese children, with intake-based risk estimates varying by EAR used.

Trust comment: Large cross-sectional dataset with measured biomarkers; observational design limits causal inference about interventions.

Study Details

PMID:26609168
Participants:598
Impact:51.3% stunting prevalence in children <5 years
Trust score:3/5

inadequate dietary zinc intake prevalence

1 evidences

Cross-sectional/preintervention data show high prevalence of low plasma zinc and stunting in rural Beninese children, with intake-based risk estimates varying by EAR used.

Trust comment: Large cross-sectional dataset with measured biomarkers; observational design limits causal inference about interventions.

Study Details

PMID:26609168
Participants:598
Impact:varied 11%–80% depending on EAR used
Trust score:3/5

plasma 5'-nucleotidase activity

1 evidences

In 20 treated postmenopausal women with NIDDM, 3 weeks of zinc raised plasma zinc and doubled 5'-nucleotidase activity; IGF-I rose in those with low baseline, and lipoprotein oxidation was unchanged.

Trust comment: Small, short-term controlled trial with clear biochemical endpoints but limited sample size and subgroup effects.

Study Details

PMID:9280186
Participants:40
Impact:+ ~100% (doubled in zinc group)
Trust score:3/5

insulin-like growth factor I (IGF-I)

1 evidences

In 20 treated postmenopausal women with NIDDM, 3 weeks of zinc raised plasma zinc and doubled 5'-nucleotidase activity; IGF-I rose in those with low baseline, and lipoprotein oxidation was unchanged.

Trust comment: Small, short-term controlled trial with clear biochemical endpoints but limited sample size and subgroup effects.

Study Details

PMID:9280186
Participants:40
Impact:+ increased in subjects with low baseline (<165 μg/L)
Trust score:3/5

cognitive performance (memory and reasoning)

1 evidences

Adolescent girls receiving zinc (tablet or zinc-rich snacks) for 10 weeks had larger increases in plasma zinc, better memory and reasoning score gains, faster reaction times, and improved salt taste sensitivity versus control.

Trust comment: Randomized school-based trial with multiple objective and functional measures and moderate sample size.

Study Details

PMID:20368377
Participants:180
Impact:+ percent score increments 24.5%–29.6% (supplement groups) vs 6.5% (control)
Trust score:4/5

taste acuity (salt recognition threshold)

1 evidences

Adolescent girls receiving zinc (tablet or zinc-rich snacks) for 10 weeks had larger increases in plasma zinc, better memory and reasoning score gains, faster reaction times, and improved salt taste sensitivity versus control.

Trust comment: Randomized school-based trial with multiple objective and functional measures and moderate sample size.

Study Details

PMID:20368377
Participants:180
Impact:- median threshold from 5 to 2.5 mmol/L (improved) in supplement groups
Trust score:4/5

growth (weight and length gains)

1 evidences

Daily zinc for 4 months raised plasma zinc and reduced diarrhea and pneumonia but did not change weight or length gains in young children.

Trust comment: Large, double-blind randomized placebo-controlled trial with clinical outcomes and high relevance.

Study Details

PMID:20107146
Participants:2482
Impact:no change (no difference between zinc and placebo)
Trust score:5/5

incidence of diarrhea and pneumonia

1 evidences

Daily zinc for 4 months raised plasma zinc and reduced diarrhea and pneumonia but did not change weight or length gains in young children.

Trust comment: Large, double-blind randomized placebo-controlled trial with clinical outcomes and high relevance.

Study Details

PMID:20107146
Participants:2482
Impact:- substantially reduced in zinc group
Trust score:5/5

elastin biosynthesis (tropoelastin)

1 evidences

Topical bi-metal (copper-zinc) cream applied twice daily for 6 weeks increased newly synthesized elastin and elastic fiber accumulation in photoaged facial skin.

Trust comment: Small open clinical sample and uses a combined copper-zinc preparation, limiting attribution to zinc alone.

Study Details

PMID:19400831
Participants:21
Impact:+ increased (statistically significant by immunofluorescence)
Trust score:3/5

elastic fibre accumulation (desmosine assay)

1 evidences

Topical bi-metal (copper-zinc) cream applied twice daily for 6 weeks increased newly synthesized elastin and elastic fiber accumulation in photoaged facial skin.

Trust comment: Small open clinical sample and uses a combined copper-zinc preparation, limiting attribution to zinc alone.

Study Details

PMID:19400831
Participants:21
Impact:+ increased (evidence of fibre regeneration)
Trust score:3/5

height (linear growth)

1 evidences

Prepubertal children with sickle cell disease receiving 10 mg Zn/day showed small but significant gains in linear growth measures over 12 months versus control.

Trust comment: Randomized trial with objective anthropometric and DXA measures but small sample size limits precision.

Study Details

PMID:11815322
Participants:38
Impact:+0.66 ± 0.29 cm/year (mean increase vs control)
Trust score:4/5

knee height

1 evidences

Prepubertal children with sickle cell disease receiving 10 mg Zn/day showed small but significant gains in linear growth measures over 12 months versus control.

Trust comment: Randomized trial with objective anthropometric and DXA measures but small sample size limits precision.

Study Details

PMID:11815322
Participants:38
Impact:+3.8 ± 1.2 mm/year (mean increase vs control)
Trust score:4/5

arm circumference z score

1 evidences

Prepubertal children with sickle cell disease receiving 10 mg Zn/day showed small but significant gains in linear growth measures over 12 months versus control.

Trust comment: Randomized trial with objective anthropometric and DXA measures but small sample size limits precision.

Study Details

PMID:11815322
Participants:38
Impact:+0.27 ± 0.12 (change per year vs control)
Trust score:4/5

body iron stores / serum ferritin

1 evidences

Daily low-dose MNP containing bioavailable iron and 2.5 mg zinc reduced iron and zinc deficiencies and modestly improved weight-for-age over 23 weeks.

Trust comment: Double-blind randomized controlled trial with clear biochemical endpoints, though zinc dose was low and some outcomes lack reported effect sizes.

Study Details

PMID:21178093
Participants:200
Impact:increased (ferritin P<0.05; body iron stores P<0.01)
Trust score:4/5

baseline serum zinc (depressed vs healthy)

1 evidences

In depressed patients treated with imipramine, serum zinc was lower than healthy controls and zinc supplementation increased serum zinc concentrations over 12 weeks.

Trust comment: Placebo-controlled double-blind clinical trial with clear biomarker endpoints but limited reporting of effect magnitudes for supplementation arm.

Study Details

PMID:20493532
Participants:60
Impact:22% lower in depressed patients vs healthy volunteers
Trust score:4/5

serum zinc with zinc supplementation

1 evidences

In depressed patients treated with imipramine, serum zinc was lower than healthy controls and zinc supplementation increased serum zinc concentrations over 12 weeks.

Trust comment: Placebo-controlled double-blind clinical trial with clear biomarker endpoints but limited reporting of effect magnitudes for supplementation arm.

Study Details

PMID:20493532
Participants:60
Impact:zinc concentrations increased over treatment and were higher with zinc supplementation vs placebo (exact increase not reported)
Trust score:4/5

risk of continued diarrhea

1 evidences

Daily 20 mg zinc in young children with acute diarrhea reduced duration and severity of diarrheal episodes, especially after day 3.

Trust comment: Large, double-blind randomized controlled trial with clinically meaningful outcomes and robust effect estimates.

Study Details

PMID:7651474
Participants:937
Impact:−23% overall risk of continued diarrhea (95% CI 12% to 32% reduction)
Trust score:5/5

mean number of watery stools per day

1 evidences

Daily 20 mg zinc in young children with acute diarrhea reduced duration and severity of diarrheal episodes, especially after day 3.

Trust comment: Large, double-blind randomized controlled trial with clinically meaningful outcomes and robust effect estimates.

Study Details

PMID:7651474
Participants:937
Impact:−39% (95% CI 6% to 70%; P=0.02)
Trust score:5/5

number of days with watery diarrhea

1 evidences

Daily 20 mg zinc in young children with acute diarrhea reduced duration and severity of diarrheal episodes, especially after day 3.

Trust comment: Large, double-blind randomized controlled trial with clinically meaningful outcomes and robust effect estimates.

Study Details

PMID:7651474
Participants:937
Impact:−21% (95% CI 10% to 31%)
Trust score:5/5

overall respiratory symptoms

1 evidences

People who gargled twice daily with a CPC+zinc mouthwash had fewer and less severe upper respiratory symptoms over 90 days than those who did not.

Trust comment: Randomized phase III trial with blinded examiners and adequate sample size but self-reported outcomes and no placebo control limit certainty.

Study Details

PMID:40009628
Participants:146
Impact:-21.5% incidence (test vs control)
Trust score:4/5

respiratory symptom severity

1 evidences

People who gargled twice daily with a CPC+zinc mouthwash had fewer and less severe upper respiratory symptoms over 90 days than those who did not.

Trust comment: Randomized phase III trial with blinded examiners and adequate sample size but self-reported outcomes and no placebo control limit certainty.

Study Details

PMID:40009628
Participants:146
Impact:-11% severity (test vs control)
Trust score:4/5

runny nose severity

1 evidences

People who gargled twice daily with a CPC+zinc mouthwash had fewer and less severe upper respiratory symptoms over 90 days than those who did not.

Trust comment: Randomized phase III trial with blinded examiners and adequate sample size but self-reported outcomes and no placebo control limit certainty.

Study Details

PMID:40009628
Participants:146
Impact:mean score difference −0.025 (Test − Control)
Trust score:4/5

incidence of diarrhoea

1 evidences

Providing zinc for 14 days during diarrhoea in children reduced duration and incidence of diarrhoea and lowered child mortality in the community trial.

Trust comment: Large community cluster-randomized trial with clear, clinically important outcomes and robust effect sizes.

Study Details

PMID:12424162
Participants:8070
Impact:reduced (rate ratio 0.85, 95% CI 0.76–0.96)
Trust score:5/5

non-injury child mortality

1 evidences

Providing zinc for 14 days during diarrhoea in children reduced duration and incidence of diarrhoea and lowered child mortality in the community trial.

Trust comment: Large community cluster-randomized trial with clear, clinically important outcomes and robust effect sizes.

Study Details

PMID:12424162
Participants:8070
Impact:reduced (rate ratio 0.49, 95% CI 0.25–0.94)
Trust score:5/5

zinc status

1 evidences

In Indonesian infants, zinc supplementation improved zinc status; iron supplementation altered plasma retinol (lower) while indicating increased liver vitamin A stores.

Trust comment: Randomized, double-blind, placebo-controlled infant trial with some loss to follow-up but clear biochemical endpoints.

Study Details

PMID:12600856
Participants:256
Impact:Improved zinc status with zinc supplementation (significant at end of study)
Trust score:4/5

daily zinc intake

3 evidences

Among 3–4-year-old children, counseling to reduce saturated fat did not change zinc intake or serum zinc concentrations compared with controls.

Trust comment: Randomized prospective study subset with measured dietary intake and laboratory zinc indicators; moderate sample size and direct zinc measurements.

Study Details

PMID:9280175
Participants:79
Impact:no significant difference (≈7.5 vs 7.4 mg/day; NS)
Trust score:4/5

In 9-month-old breastfed infants, meat or zinc-fortified cereal provided more absorbed zinc than iron-only fortified cereal; human-milk zinc contributed <25% of needs.

Trust comment: Randomized feeding trial with direct isotope-based zinc absorption measures but small sample size limits generalizability.

Study Details

PMID:22648720
Participants:45
Impact:significantly greater in meat and IZFC groups vs IFC (P < 0.001)
Trust score:4/5

Providing biofortified wheat increased dietary zinc by ~1.5 mg/day but did not raise plasma zinc; it was associated with a reduction in an inflammation marker (AGP).

Trust comment: Large double-blind cluster RCT with good sample size, high compliance, and appropriate analyses; results robust.

Study Details

PMID:35458222
Participants:407
Impact:+1.5 mg/day (≈22% increase)
Trust score:5/5

antioxidant markers

1 evidences

Adolescent athletes taking 22 mg/day zinc for 12 weeks showed improved antioxidant markers but decreased plasma iron and copper.

Trust comment: Placebo-controlled trial in adolescents with clear biochemical outcomes but small sample and potential nutritional interactions.

Study Details

PMID:19277992
Participants:47
Impact:improved (plasma ferric-reducing ability increased; some antioxidant markers improved more in Zn group)
Trust score:4/5

plasma iron

3 evidences

Giving one egg daily for six months did not improve plasma zinc, selenium, copper or magnesium; plasma iron decreased in the egg group.

Trust comment: Large randomized controlled trial with blinded outcome assessment and measured biomarkers; secondary analysis with some sample loss but appropriate adjustments.

Study Details

PMID:37095119
Participants:387
Impact:Mean difference −9.07 µg/dL (95% CI −15.63 to −2.51); significant decrease in intervention group
Trust score:4/5

Adolescent athletes taking 22 mg/day zinc for 12 weeks showed improved antioxidant markers but decreased plasma iron and copper.

Trust comment: Placebo-controlled trial in adolescents with clear biochemical outcomes but small sample and potential nutritional interactions.

Study Details

PMID:19277992
Participants:47
Impact:decreased in Zn-supplemented group (p = 0.01)
Trust score:4/5

Randomized double-blind trial in obese hypertensive adults: 3 months of Spirulina (2 g/day) decreased serum iron but did not markedly change serum calcium or magnesium.

Trust comment: Randomized controlled design but small sample and spirulina is a multi-component supplement; zinc concentration change was not significant.

Study Details

PMID:26779620
Participants:50
Impact:significant decrease in iron in spirulina group (reported in paper)
Trust score:3/5

albumin level

1 evidences

Zinc given to children with severe malnutrition led to biochemical zinc recovery, higher albumin and improved blood parameters, and fewer deaths compared with controls.

Trust comment: Large randomized double-blind controlled trial in 300 children with objective biochemical and clinical endpoints, though exact effect sizes for some outcomes are not reported.

Study Details

PMID:14725412
Participants:300
Impact:significant increase
Trust score:4/5

plaque zinc concentration

1 evidences

Regular use of a toothpaste with zinc citrate led to measurable accumulation of zinc (and triclosan) in dental plaque that persisted after controlled food intake.

Trust comment: Moderate-quality controlled human study measuring plaque agent concentrations with a modest sample size, but clinical endpoints were not directly assessed.

Study Details

PMID:14725382
Participants:104
Impact:increased (149.1 µg/g at 12 h after 2-week use; 94.7 µg/g after morning brushing and controlled intake)
Trust score:3/5

plaque triclosan concentration

1 evidences

Regular use of a toothpaste with zinc citrate led to measurable accumulation of zinc (and triclosan) in dental plaque that persisted after controlled food intake.

Trust comment: Moderate-quality controlled human study measuring plaque agent concentrations with a modest sample size, but clinical endpoints were not directly assessed.

Study Details

PMID:14725382
Participants:104
Impact:increased (8.6 µg/g at 12 h after 2-week use; 4.1 µg/g after morning brushing and controlled intake)
Trust score:3/5

antibacterial effect (pH drop reduction)

1 evidences

Regular use of a toothpaste with zinc citrate led to measurable accumulation of zinc (and triclosan) in dental plaque that persisted after controlled food intake.

Trust comment: Moderate-quality controlled human study measuring plaque agent concentrations with a modest sample size, but clinical endpoints were not directly assessed.

Study Details

PMID:14725382
Participants:104
Impact:reduction in pH drop observed in vitro associated with measured agent levels
Trust score:3/5

infant birth weight

1 evidences

Daily 25 mg zinc in pregnant women with lower baseline zinc was associated with higher infant birth weight and larger head circumference, especially in women with BMI <26.

Trust comment: Large randomized double-blind placebo-controlled trial with significant, clinically relevant infant outcome measures and subgroup effects reported.

Study Details

PMID:7629954
Participants:580
Impact:+126 g overall (P = .03); +248 g in women with BMI <26 (P = .005)
Trust score:4/5

infant head circumference

1 evidences

Daily 25 mg zinc in pregnant women with lower baseline zinc was associated with higher infant birth weight and larger head circumference, especially in women with BMI <26.

Trust comment: Large randomized double-blind placebo-controlled trial with significant, clinically relevant infant outcome measures and subgroup effects reported.

Study Details

PMID:7629954
Participants:580
Impact:+0.4 cm overall (P = .02); +0.7 cm in women with BMI <26 (P = .007)
Trust score:4/5

stunting (height-for-age)

1 evidences

Between 2002 and 2012 zinc status in rural Chinese schoolchildren improved markedly (higher serum zinc, lower prevalence of deficiency and stunting).

Trust comment: Large, population-based survey using established WHO/UNICEF/IAEA/IZiNCG indicators across two time points, providing robust observational trends.

Study Details

PMID:28101714
Participants:3407
Impact:reduction in stunting from 19.1% (2002) to 6.8% (2012)
Trust score:4/5

height

1 evidences

Daily 10 mg zinc for 5 months increased weight and height, raised circulating IGF-I, and reduced episodes of diarrhea and respiratory infections in growth-retarded children.

Trust comment: Double-blind randomized study with clear growth and infection outcomes and biologic correlates (IGF-I), sample size moderate and well-reported.

Study Details

PMID:8599314
Participants:146
Impact:+1.5 ± 0.2 cm after 5 months (P < 0.001)
Trust score:4/5

IGF-I concentration

1 evidences

Daily 10 mg zinc for 5 months increased weight and height, raised circulating IGF-I, and reduced episodes of diarrhea and respiratory infections in growth-retarded children.

Trust comment: Double-blind randomized study with clear growth and infection outcomes and biologic correlates (IGF-I), sample size moderate and well-reported.

Study Details

PMID:8599314
Participants:146
Impact:increased (from 1.9 to 3.4 nmol/L in placebo vs zinc groups over 5 months; significant differences at 1 and 5 months)
Trust score:4/5

diarrheal episodes

1 evidences

Daily 10 mg zinc for 5 months increased weight and height, raised circulating IGF-I, and reduced episodes of diarrhea and respiratory infections in growth-retarded children.

Trust comment: Double-blind randomized study with clear growth and infection outcomes and biologic correlates (IGF-I), sample size moderate and well-reported.

Study Details

PMID:8599314
Participants:146
Impact:relative risk reduced ~3-fold (P = 0.012)
Trust score:4/5

zinc absorption (serum Zn AUC)

1 evidences

Phytic acid in soya milk significantly reduced zinc absorption in both young and elderly; no difference between age groups.

Trust comment: Human crossover studies with objective serum measures but small combined sample size (n=39) and limited power.

Study Details

PMID:9828759
Participants:39
Impact:decreased by phytic acid (P ≤ 0.05); greater inhibition at 0.26 g/200 ml vs 0 g
Trust score:3/5

age effect on Zn absorption

1 evidences

Phytic acid in soya milk significantly reduced zinc absorption in both young and elderly; no difference between age groups.

Trust comment: Human crossover studies with objective serum measures but small combined sample size (n=39) and limited power.

Study Details

PMID:9828759
Participants:39
Impact:no significant difference between young and elderly
Trust score:3/5

weight gain (zinc-deficient infants)

1 evidences

Daily 5 mg zinc raised serum zinc overall and improved weight gain and reduced lower respiratory infection incidence in infants who were zinc-deficient at baseline.

Trust comment: Large randomized placebo-controlled trial with objective biochemical and clinical outcomes and clear subgroup effects.

Study Details

PMID:12450909
Participants:301
Impact:+0.49 kg over study (3.15 ±0.77 vs 2.66 ±0.80 kg; P < 0.04)
Trust score:5/5

acute lower respiratory infection incidence (zinc-deficient infants)

1 evidences

Daily 5 mg zinc raised serum zinc overall and improved weight gain and reduced lower respiratory infection incidence in infants who were zinc-deficient at baseline.

Trust comment: Large randomized placebo-controlled trial with objective biochemical and clinical outcomes and clear subgroup effects.

Study Details

PMID:12450909
Participants:301
Impact:reduced (RR 0.30; 95% CI 0.10–0.92; ~70% lower risk)
Trust score:5/5

hearing threshold improvement (PTA)

1 evidences

Adding oral zinc to standard steroid treatment showed no additional hearing benefit compared with standard treatment alone.

Trust comment: Prospective randomized study but small sample (n=30) and no between-group benefit detected.

Study Details

PMID:25958716
Participants:30
Impact:both groups improved but no significant difference between zinc+standard vs standard alone (p > 0.05)
Trust score:3/5

speech discrimination score (SDS)

1 evidences

Adding oral zinc to standard steroid treatment showed no additional hearing benefit compared with standard treatment alone.

Trust comment: Prospective randomized study but small sample (n=30) and no between-group benefit detected.

Study Details

PMID:25958716
Participants:30
Impact:improved in both groups with no significant difference between groups (p > 0.05)
Trust score:3/5

observed playing time

1 evidences

Daily 10 mg zinc for up to 7 months increased observed playing and sitting behavior in infants, with no change in motor development.

Trust comment: Randomized double-blind placebo-controlled trial with objective observational measures and moderate sample size (n=85).

Study Details

PMID:9202087
Participants:85
Impact:+4.18 ±1.95% of observations playing (P < 0.05) after 7 months
Trust score:4/5

motor development

3 evidences

In Zanzibari infants, iron+folic acid with or without zinc improved motor development; zinc alone was associated with worse language development in the 10–14 month group.

Trust comment: Substudy of a randomized, placebo-controlled 2×2 factorial trial with longitudinal measures, giving moderate confidence in observed effects.

Study Details

PMID:23725789
Participants:247
Impact:positive effect with iron+folic acid with or without zinc
Trust score:4/5

Daily 10 mg zinc for up to 7 months increased observed playing and sitting behavior in infants, with no change in motor development.

Trust comment: Randomized double-blind placebo-controlled trial with objective observational measures and moderate sample size (n=85).

Study Details

PMID:9202087
Participants:85
Impact:no difference between zinc and placebo groups
Trust score:4/5

Weekly iron and zinc (together or individually) improved infant motor development and attention/orientation measures between 6 and 12 months.

Trust comment: Double-blind randomized trial with relevant developmental assessments, moderate sample and appropriate adjustments reported.

Study Details

PMID:15447897
Participants:221
Impact:improved (beneficial effect when iron and zinc administered together)
Trust score:4/5

urine zinc:creatinine ratio

1 evidences

Daily zinc (5–15 mg) for 4 months increased urinary zinc excretion but did not depress sensitive biomarkers of copper status in healthy boys.

Trust comment: Double-blind randomized trial with sensitive biochemical endpoints though group sizes per dose were small (total n=37).

Study Details

PMID:23303874
Participants:37
Impact:increased at 4 months compared with placebo (P = 0.02)
Trust score:4/5

copper status biomarkers (plasma copper, ceruloplasmin, erythrocyte SOD1, CCS:SOD1)

1 evidences

Daily zinc (5–15 mg) for 4 months increased urinary zinc excretion but did not depress sensitive biomarkers of copper status in healthy boys.

Trust comment: Double-blind randomized trial with sensitive biochemical endpoints though group sizes per dose were small (total n=37).

Study Details

PMID:23303874
Participants:37
Impact:no change (no evidence of depressed copper status)
Trust score:4/5

night vision restoration

1 evidences

Daily 25 mg zinc for 3 weeks raised serum zinc but did not restore night vision by itself; it appeared to help vitamin A restore night vision in women with low baseline zinc.

Trust comment: Randomized, double-blind trial with 202 participants and objective measures; subgroup effect and borderline p-value limit certainty.

Study Details

PMID:11382658
Participants:202
Impact:no effect with zinc alone; +4x likelihood (OR=4.0; 95% CI 1.1–17.3) when combined with vitamin A in women with baseline Zn <9.9 µmol/L
Trust score:4/5

pupillary threshold (dark adaptation)

1 evidences

Daily 25 mg zinc for 3 weeks raised serum zinc but did not restore night vision by itself; it appeared to help vitamin A restore night vision in women with low baseline zinc.

Trust comment: Randomized, double-blind trial with 202 participants and objective measures; subgroup effect and borderline p-value limit certainty.

Study Details

PMID:11382658
Participants:202
Impact:small improvement of 0.21 log candela/m2 (P=0.09) in vitamin A+zinc subgroup
Trust score:4/5

clinical treatment efficacy (AAD)

1 evidences

Adding zinc to probiotics improved clinical response in children with antibiotic-associated diarrhea and improved gut bacterial balance and gut permeability markers.

Trust comment: Randomized study but small sample size and limited reporting details reduce confidence.

Study Details

PMID:30521044
Participants:75
Impact:combined zinc+probiotic had significantly higher overall efficacy vs probiotic alone
Trust score:3/5

Bifidobacterium / E. coli ratio

1 evidences

Adding zinc to probiotics improved clinical response in children with antibiotic-associated diarrhea and improved gut bacterial balance and gut permeability markers.

Trust comment: Randomized study but small sample size and limited reporting details reduce confidence.

Study Details

PMID:30521044
Participants:75
Impact:Bifidobacterium increased; E. coli decreased; B/E ratio improved
Trust score:3/5

intestinal barrier markers (DAO, D-lactate)

1 evidences

Adding zinc to probiotics improved clinical response in children with antibiotic-associated diarrhea and improved gut bacterial balance and gut permeability markers.

Trust comment: Randomized study but small sample size and limited reporting details reduce confidence.

Study Details

PMID:30521044
Participants:75
Impact:DAO activity and D-lactate levels were markedly reduced after combined treatment
Trust score:3/5

1-month mortality

1 evidences

Zinc supplementation after severe head injury was associated with lower 1-month mortality, better early neurologic recovery, and higher visceral protein levels.

Trust comment: Randomized, prospective, double-blind trial showing clinically meaningful outcomes, though some imbalance in surgical interventions noted.

Study Details

PMID:8714860
Participants:68
Impact:reduced from 26% (standard) to 12% (zinc-supplemented) at 1 month
Trust score:4/5

neurologic recovery (GCS scores)

1 evidences

Zinc supplementation after severe head injury was associated with lower 1-month mortality, better early neurologic recovery, and higher visceral protein levels.

Trust comment: Randomized, prospective, double-blind trial showing clinically meaningful outcomes, though some imbalance in surgical interventions noted.

Study Details

PMID:8714860
Participants:68
Impact:higher GCS scores in zinc group (motor GCS significantly higher on days 15 and 21; adjusted mean higher at day 28, p=0.03)
Trust score:4/5

visceral protein concentrations (prealbumin, RBP)

1 evidences

Zinc supplementation after severe head injury was associated with lower 1-month mortality, better early neurologic recovery, and higher visceral protein levels.

Trust comment: Randomized, prospective, double-blind trial showing clinically meaningful outcomes, though some imbalance in surgical interventions noted.

Study Details

PMID:8714860
Participants:68
Impact:prealbumin increased (p=0.003); retinol binding protein increased (p=0.01)
Trust score:4/5

oxidative stress markers (lipid peroxidation, DNA oxidation, NOx)

1 evidences

Three months of zinc (25 mg thrice daily) in adults with sickle cell disease reduced infections, lowered oxidative stress markers, and reduced proinflammatory cytokine expression.

Trust comment: Small randomized placebo-controlled trial with consistent biomarker changes, but limited size and short duration.

Study Details

PMID:18674741
Participants:36
Impact:decreased lipid peroxidation products, DNA oxidation products, and plasma NOx
Trust score:3/5

proinflammatory cytokine mRNA and NF-κB activity

1 evidences

Three months of zinc (25 mg thrice daily) in adults with sickle cell disease reduced infections, lowered oxidative stress markers, and reduced proinflammatory cytokine expression.

Trust comment: Small randomized placebo-controlled trial with consistent biomarker changes, but limited size and short duration.

Study Details

PMID:18674741
Participants:36
Impact:decreased LPS-induced TNF-α and IL-1β mRNAs and reduced NF-κB–DNA binding; increased IL-2/IL-2Rα mRNAs on stimulation
Trust score:3/5

adverse treatment side effects

1 evidences

Zinc supplementation restored serum zinc levels and reduced some treatment side effects but did not change virologic response to interferon/ribavirin.

Trust comment: Randomized study but small sample size; biochemical and tolerability endpoints improved while virologic efficacy unchanged.

Study Details

PMID:15904908
Participants:40
Impact:certain adverse side effects significantly decreased with zinc supplementation
Trust score:3/5

virologic response (HCV)

1 evidences

Zinc supplementation restored serum zinc levels and reduced some treatment side effects but did not change virologic response to interferon/ribavirin.

Trust comment: Randomized study but small sample size; biochemical and tolerability endpoints improved while virologic efficacy unchanged.

Study Details

PMID:15904908
Participants:40
Impact:no apparent difference between zinc and no-zinc groups
Trust score:3/5

oxidative stress markers (ox-LDL, malondialdehyde)

1 evidences

In obese prepubescent children, 20 mg/day zinc for 8 weeks reduced oxidative stress markers, improved lipid measures, lowered inflammatory and insulin-resistance markers, and reduced weight/BMI relative to placebo.

Trust comment: Triple-masked randomized crossover with 60 participants and consistent biomarker changes supports moderate-to-high confidence.

Study Details

PMID:21028969
Participants:60
Impact:significant decrease after zinc supplementation
Trust score:4/5

insulin resistance / inflammation (hs-CRP, insulin markers)

1 evidences

In obese prepubescent children, 20 mg/day zinc for 8 weeks reduced oxidative stress markers, improved lipid measures, lowered inflammatory and insulin-resistance markers, and reduced weight/BMI relative to placebo.

Trust comment: Triple-masked randomized crossover with 60 participants and consistent biomarker changes supports moderate-to-high confidence.

Study Details

PMID:21028969
Participants:60
Impact:hs-CRP and markers of insulin resistance decreased significantly with zinc
Trust score:4/5

lipid profile (total and LDL-cholesterol, Apo B/ApoA-I)

1 evidences

In obese prepubescent children, 20 mg/day zinc for 8 weeks reduced oxidative stress markers, improved lipid measures, lowered inflammatory and insulin-resistance markers, and reduced weight/BMI relative to placebo.

Trust comment: Triple-masked randomized crossover with 60 participants and consistent biomarker changes supports moderate-to-high confidence.

Study Details

PMID:21028969
Participants:60
Impact:total and LDL-cholesterol and Apo B/ApoA-I ratio decreased significantly after zinc
Trust score:4/5

incidence of pneumonia (nonsevere and severe)

1 evidences

A 14-day zinc course given during pneumonia raised plasma zinc short-term but did not reduce subsequent pneumonia or diarrhea over 6 months.

Trust comment: Large randomized, double-blind, placebo-controlled trial with high follow-up (99%) providing robust null findings for prevention.

Study Details

PMID:20631326
Participants:2599
Impact:no preventive effect over 6 months (HR 1.02 for nonsevere; 1.11 for severe)
Trust score:5/5

incidence of diarrhea/dysentery

1 evidences

A 14-day zinc course given during pneumonia raised plasma zinc short-term but did not reduce subsequent pneumonia or diarrhea over 6 months.

Trust comment: Large randomized, double-blind, placebo-controlled trial with high follow-up (99%) providing robust null findings for prevention.

Study Details

PMID:20631326
Participants:2599
Impact:no preventive effect over 6 months (HR 1.07 for diarrhea; 0.96 for dysentery)
Trust score:5/5

leukocyte zinc concentration

1 evidences

Children with low serum zinc ate zinc-fortified bread for 90 days and showed increases in zinc status, some growth markers, and immune responses.

Trust comment: Small controlled feeding study with clear biochemical and clinical signals but limited sample size (n=24) reduces generalizability.

Study Details

PMID:9481631
Participants:24
Impact:Increased (p<0.01)
Trust score:3/5

weight / serum albumin / alkaline phosphatase

1 evidences

Children with low serum zinc ate zinc-fortified bread for 90 days and showed increases in zinc status, some growth markers, and immune responses.

Trust comment: Small controlled feeding study with clear biochemical and clinical signals but limited sample size (n=24) reduces generalizability.

Study Details

PMID:9481631
Participants:24
Impact:All increased (p<0.01); immune skin-test responses improved (conversion of delayed hypersensitivity)
Trust score:3/5

common cold duration

1 evidences

Methodological analysis using IPD from two zinc lozenge RCTs showing zinc lozenges substantially shortened cold duration; relative (%) scale fits data better.

Trust comment: Rigorous re-analysis of individual-patient data from two randomized trials; high methodological quality though secondary analysis.

Study Details

PMID:28494765
Participants:200
Impact:Mossad trial: −4.00 days (−43.4%); Petrus trial: −1.77 days (−25.1%) — both significant
Trust score:4/5

serum/erythrocyte/hair zinc concentration

1 evidences

Newly diagnosed hypertensive patients on monotherapy given zinc supplementation showed improved zinc status and lower serum glucose without changing blood pressure.

Trust comment: Randomized groups and multiple biochemical measures support moderate–high trust, but modest sample size and complexity of interventions limit certainty.

Study Details

PMID:29544801
Participants:98
Impact:Increased in zinc-supplemented group (improved zinc homeostasis)
Trust score:4/5

serum glucose concentration

1 evidences

Newly diagnosed hypertensive patients on monotherapy given zinc supplementation showed improved zinc status and lower serum glucose without changing blood pressure.

Trust comment: Randomized groups and multiple biochemical measures support moderate–high trust, but modest sample size and complexity of interventions limit certainty.

Study Details

PMID:29544801
Participants:98
Impact:Decreased in groups with higher zinc intake (significant correlation between zinc and glucose)
Trust score:4/5

linear growth (length/height)

1 evidences

Undernourished young children given 5 mg elemental zinc daily for 12 weeks showed no growth benefit but fewer hospitalizations and shorter skin rash episodes.

Trust comment: Randomized, placebo-controlled trial in children but modest sample size and some exclusions reduce precision of estimates.

Study Details

PMID:9481530
Participants:57
Impact:No significant effect
Trust score:3/5

hospitalizations (severity proxy)

1 evidences

Undernourished young children given 5 mg elemental zinc daily for 12 weeks showed no growth benefit but fewer hospitalizations and shorter skin rash episodes.

Trust comment: Randomized, placebo-controlled trial in children but modest sample size and some exclusions reduce precision of estimates.

Study Details

PMID:9481530
Participants:57
Impact:Reduced in supplemented group (Fisher's exact test, p=0.02)
Trust score:3/5

skin rash episode duration

1 evidences

Undernourished young children given 5 mg elemental zinc daily for 12 weeks showed no growth benefit but fewer hospitalizations and shorter skin rash episodes.

Trust comment: Randomized, placebo-controlled trial in children but modest sample size and some exclusions reduce precision of estimates.

Study Details

PMID:9481530
Participants:57
Impact:Shorter in supplemented group (ANCOVA, p=0.02)
Trust score:3/5

anthropometric measures (linear growth, MUAC, skinfolds)

1 evidences

In severely malnourished young children, higher-dose zinc did not improve growth and was linked to higher death rates.

Trust comment: Randomized double-blind trial in humans with clear mortality signal but relatively small sample and specific severe-malnutrition setting.

Study Details

PMID:9734756
Participants:141
Impact:no significant change
Trust score:4/5

recovery rate from diarrhoea

1 evidences

Zinc given for acute diarrhoea reduced stool frequency and improved recovery; suspension form had better outcomes and compliance than tablets.

Trust comment: Cohort study in an emergency field setting with 200 children; non-randomized allocation limits causal inference.

Study Details

PMID:21205556
Participants:200
Impact:improved (better in suspension group)
Trust score:3/5

zinc micronutrient adequacy

1 evidences

Observational cohort of Zambian infants found that micronutrient adequacy (including calcium) and dietary diversity were positively associated with linear growth to 18 months.

Trust comment: Large longitudinal observational cohort showing associations but potential confounding and reliance on dietary recall.

Study Details

PMID:27581574
Participants:811
Impact:associated with improved linear growth to 18 months (P ≤ 0.028)
Trust score:3/5

dietary diversity

1 evidences

Observational cohort of Zambian infants found that micronutrient adequacy (including calcium) and dietary diversity were positively associated with linear growth to 18 months.

Trust comment: Large longitudinal observational cohort showing associations but potential confounding and reliance on dietary recall.

Study Details

PMID:27581574
Participants:811
Impact:positively associated with linear growth independent of micronutrient adequacy
Trust score:3/5

overall treatment response rate

1 evidences

Adding oral zinc to usual care for infants with rotavirus reduced symptom durations, improved response rate, and lowered 3-month recurrence and severe-recurrence rates.

Trust comment: Randomized trial with modest sample (n=103) and positive clinical outcomes, but single-center and limited reporting details.

Study Details

PMID:27655538
Participants:103
Impact:90% vs 75% (zinc vs control)
Trust score:3/5

diarrhoea recurrence within 3 months

1 evidences

Adding oral zinc to usual care for infants with rotavirus reduced symptom durations, improved response rate, and lowered 3-month recurrence and severe-recurrence rates.

Trust comment: Randomized trial with modest sample (n=103) and positive clinical outcomes, but single-center and limited reporting details.

Study Details

PMID:27655538
Participants:103
Impact:reduced (P < 0.05)
Trust score:3/5

days ill

1 evidences

High prevalence of zinc deficiency; children with low baseline plasma zinc experienced more days ill and more days with diarrhoea and ALRI over follow-up.

Trust comment: Large community-based cohort with baseline plasma zinc and prospective morbidity follow-up, providing robust associative data.

Study Details

PMID:19902798
Participants:940
Impact:↑13% (adjusted RR 1.13; 95% CI 1.06–1.20) in lower vs upper zinc quartile over 120 days
Trust score:4/5

days with diarrhoea

1 evidences

High prevalence of zinc deficiency; children with low baseline plasma zinc experienced more days ill and more days with diarrhoea and ALRI over follow-up.

Trust comment: Large community-based cohort with baseline plasma zinc and prospective morbidity follow-up, providing robust associative data.

Study Details

PMID:19902798
Participants:940
Impact:↑32% (adjusted RR 1.32; 95% CI 1.18–1.49) in lower vs upper zinc quartile
Trust score:4/5

days with ALRI

1 evidences

High prevalence of zinc deficiency; children with low baseline plasma zinc experienced more days ill and more days with diarrhoea and ALRI over follow-up.

Trust comment: Large community-based cohort with baseline plasma zinc and prospective morbidity follow-up, providing robust associative data.

Study Details

PMID:19902798
Participants:940
Impact:↑47% (adjusted RR 1.47; 95% CI 1.14–1.90) in lower vs upper zinc quartile
Trust score:4/5

oral volatile sulfur compounds (VSC)

1 evidences

Sugar-free tablets with zinc lactate + magnolia bark extract reduced oral volatile sulfur compounds more than placebo for up to 2 hours.

Trust comment: Well-conducted randomized double-blind trial with objective VSC measurement and 100 completers, but outcome is short-term (2 hours).

Study Details

PMID:26054178
Participants:100
Impact:-62% at 8 min (test) vs -39% (control); -30% at 1 h vs -6%; -18% at 2 h vs -2% (all p<0.001 vs baseline; between-group p values: 8 min p<0.01, 1 h p<0.001, 2 h p<0.05)
Trust score:4/5

Cognitive Composite 2 (CC2)

1 evidences

In this 24-week randomized double-blind trial zinc did not differ from placebo overall, but a post-hoc pharmacodynamic 'Responder' subgroup (≥20% ceruloplasmin reduction) showed cognitive stabilization versus decline in others.

Trust comment: Randomized double-blind design and objective biomarker use are strengths, but analysis relies on a small, underpowered sample and post-hoc responder subgroup.

Study Details

PMID:41008575
Participants:48
Impact:between-group difference in change (Responder vs Non-Responder+Placebo): Δ = -2.05, SE = 0.63; p=0.006 (responders stable, others declined)
Trust score:3/5

CDR-Sum of Boxes (CDR-Sob)

1 evidences

In this 24-week randomized double-blind trial zinc did not differ from placebo overall, but a post-hoc pharmacodynamic 'Responder' subgroup (≥20% ceruloplasmin reduction) showed cognitive stabilization versus decline in others.

Trust comment: Randomized double-blind design and objective biomarker use are strengths, but analysis relies on a small, underpowered sample and post-hoc responder subgroup.

Study Details

PMID:41008575
Participants:48
Impact:between-group difference in change: Δ = -1.29, SE = 0.35; p=0.002 (responders stable, others declined)
Trust score:3/5

MMSE

1 evidences

In this 24-week randomized double-blind trial zinc did not differ from placebo overall, but a post-hoc pharmacodynamic 'Responder' subgroup (≥20% ceruloplasmin reduction) showed cognitive stabilization versus decline in others.

Trust comment: Randomized double-blind design and objective biomarker use are strengths, but analysis relies on a small, underpowered sample and post-hoc responder subgroup.

Study Details

PMID:41008575
Participants:48
Impact:between-group difference in change: Δ = +2.12, SE = 0.71; p=0.012 (responders improved/stable vs decline)
Trust score:3/5

ceruloplasmin (pharmacodynamic marker)

1 evidences

In this 24-week randomized double-blind trial zinc did not differ from placebo overall, but a post-hoc pharmacodynamic 'Responder' subgroup (≥20% ceruloplasmin reduction) showed cognitive stabilization versus decline in others.

Trust comment: Randomized double-blind design and objective biomarker use are strengths, but analysis relies on a small, underpowered sample and post-hoc responder subgroup.

Study Details

PMID:41008575
Participants:48
Impact:Responders defined by ≥20% reduction at week 12; 12 responders identified among those with Cp data
Trust score:3/5

length-for-age z-score (LAZ)

1 evidences

Comparative analyses of neighboring trials found that small-quantity LNS—but not the zinc supplementation regimens used—was associated with improved linear growth (LAZ, WAZ) in infants aged ≈9–15 months.

Trust comment: Large cluster-randomized trials and thorough adjusted analyses support conclusions, though comparisons span two separate trials with differing designs and contexts.

Study Details

PMID:28771493
Participants:4046
Impact:LNS group showed significantly greater improvements in LAZ versus zinc-supplemented groups across 9–15 months (difference persisted after covariate adjustment)
Trust score:4/5

linear growth (16-week comparison cited)

1 evidences

Comparative analyses of neighboring trials found that small-quantity LNS—but not the zinc supplementation regimens used—was associated with improved linear growth (LAZ, WAZ) in infants aged ≈9–15 months.

Trust comment: Large cluster-randomized trials and thorough adjusted analyses support conclusions, though comparisons span two separate trials with differing designs and contexts.

Study Details

PMID:28771493
Participants:4046
Impact:prior zinc trial: zinc groups gained ~3.15–3.20 cm vs 3.36 cm in non-zinc over 16 weeks (zinc not superior; p<0.001 reported in source introduction)
Trust score:4/5

time in high-movement activities

1 evidences

In a sub-study of a randomized trial, daily 10 mg elemental zinc increased observed activity levels in preschool children compared with controls.

Trust comment: Derived from a randomized controlled supplementation trial but small sub-study sample and short observation window limit strength of inference.

Study Details

PMID:8951265
Participants:93
Impact:+72% (zinc vs control)
Trust score:3/5

activity rating score

1 evidences

In a sub-study of a randomized trial, daily 10 mg elemental zinc increased observed activity levels in preschool children compared with controls.

Trust comment: Derived from a randomized controlled supplementation trial but small sub-study sample and short observation window limit strength of inference.

Study Details

PMID:8951265
Participants:93
Impact:+12% (zinc vs control)
Trust score:3/5

energy expenditure score

1 evidences

In a sub-study of a randomized trial, daily 10 mg elemental zinc increased observed activity levels in preschool children compared with controls.

Trust comment: Derived from a randomized controlled supplementation trial but small sub-study sample and short observation window limit strength of inference.

Study Details

PMID:8951265
Participants:93
Impact:+8.3% (zinc vs control)
Trust score:3/5

persistent diarrhea (children with ≥1 episode)

1 evidences

Daily 10 mg zinc for 7 months reduced diarrhea incidence and persistent diarrhea in young Guatemalan children; no clear effect on respiratory infections.

Trust comment: Randomized double-blind community trial with daily morbidity surveillance; moderate sample size but rigorous design.

Study Details

PMID:9164774
Participants:89
Impact:-67% prevalence
Trust score:4/5

diarrhoea episodes (stunted children)

1 evidences

Two-week zinc (20 mg/d) during acute diarrhoea improved subsequent linear growth and reduced diarrhoea and respiratory episodes in malnourished subgroups over 8 weeks.

Trust comment: Double-blind RCT in malnourished children with clear outcome measures but modest sample size.

Study Details

PMID:10452407
Participants:65
Impact:-0.53 episodes (0.07 vs 0.6)
Trust score:4/5

respiratory illness episodes (stunted children)

1 evidences

Two-week zinc (20 mg/d) during acute diarrhoea improved subsequent linear growth and reduced diarrhoea and respiratory episodes in malnourished subgroups over 8 weeks.

Trust comment: Double-blind RCT in malnourished children with clear outcome measures but modest sample size.

Study Details

PMID:10452407
Participants:65
Impact:-1.4 episodes (1.0 vs 2.4)
Trust score:4/5

exchangeable zinc pool mass (EZP)

1 evidences

Six months of daily 15 or 30 mg zinc increased the masses of exchangeable zinc pools in healthy late-middle-aged men.

Trust comment: Controlled supplementation and stable-isotope kinetic measures in a small, well-characterized human sample.

Study Details

PMID:16002807
Participants:48
Impact:increased (statistically significant)
Trust score:4/5

CMI anergy prevalence

1 evidences

120 days of zinc (10 mg/d) improved cell-mediated immunity and increased CD3 and CD4 counts and CD4/CD8 ratio in preschool children.

Trust comment: Double-blind RCT with immunologic endpoints and flow cytometry in a community sample; sample sizes moderate.

Study Details

PMID:9401251
Participants:86
Impact:-20 percentage points (67%→47%)
Trust score:4/5

CD4 count

2 evidences

120 days of zinc (10 mg/d) improved cell-mediated immunity and increased CD3 and CD4 counts and CD4/CD8 ratio in preschool children.

Trust comment: Double-blind RCT with immunologic endpoints and flow cytometry in a community sample; sample sizes moderate.

Study Details

PMID:9401251
Participants:86
Impact:+64% geometric mean
Trust score:4/5

In HIV+ patients on ART, zinc supplementation reduced the risk of opportunistic infections but did not significantly change CD4 counts.

Trust comment: Randomized double-blind clinical trial in 146 patients with clear clinical endpoints; effect sizes partly not reported numerically but statistical significance given.

Study Details

PMID:30888253
Participants:146
Impact:no significant change
Trust score:4/5

CD3 count

1 evidences

120 days of zinc (10 mg/d) improved cell-mediated immunity and increased CD3 and CD4 counts and CD4/CD8 ratio in preschool children.

Trust comment: Double-blind RCT with immunologic endpoints and flow cytometry in a community sample; sample sizes moderate.

Study Details

PMID:9401251
Participants:86
Impact:+25% geometric mean
Trust score:4/5

CD4/CD8 ratio

1 evidences

120 days of zinc (10 mg/d) improved cell-mediated immunity and increased CD3 and CD4 counts and CD4/CD8 ratio in preschool children.

Trust comment: Double-blind RCT with immunologic endpoints and flow cytometry in a community sample; sample sizes moderate.

Study Details

PMID:9401251
Participants:86
Impact:+73% geometric mean
Trust score:4/5

height-for-age

1 evidences

Malnourished children had lower blood zinc and copper; zinc levels correlated with linear growth.

Trust comment: Clinical observational measurements in 58 children with clear correlations reported but cross-sectional design and small sample limit causal inference.

Study Details

PMID:10829989
Participants:58
Impact:positive correlation with serum zinc (r=0.8809, p<0.001)
Trust score:3/5

midarm muscle area (MMA)

1 evidences

Daily zinc for ~7 months increased muscle area and improved linear growth in infants who were stunted at baseline.

Trust comment: Community-based double-blind randomized trial with clear anthropometric outcomes though sample size modest.

Study Details

PMID:9482763
Participants:89
Impact:+0.61 cm2 overall (P = 0.02)
Trust score:4/5

length increment (linear growth)

1 evidences

Daily zinc for ~7 months increased muscle area and improved linear growth in infants who were stunted at baseline.

Trust comment: Community-based double-blind randomized trial with clear anthropometric outcomes though sample size modest.

Study Details

PMID:9482763
Participants:89
Impact:+0.75 cm overall (P = 0.12); +1.40 cm in stunted infants (interaction P = 0.04)
Trust score:4/5

diarrhea prevalence

1 evidences

5 mg/day zinc reduced diarrhea prevalence and increased weight gain during weeks 17–26 in low-birth-weight infants.

Trust comment: Randomized trial with three arms and active morbidity surveillance; good internal validity though effect sizes modest.

Study Details

PMID:9701155
Participants:205
Impact:reduced by 28% over 6 months (adjusted P = 0.043) with 5 mg Zn
Trust score:4/5

cough prevalence

1 evidences

5 mg/day zinc reduced diarrhea prevalence and increased weight gain during weeks 17–26 in low-birth-weight infants.

Trust comment: Randomized trial with three arms and active morbidity surveillance; good internal validity though effect sizes modest.

Study Details

PMID:9701155
Participants:205
Impact:reduced by 33% (not statistically significant, adjusted P = 0.073) with 5 mg Zn
Trust score:4/5

weight gain (weeks 17–26)

1 evidences

5 mg/day zinc reduced diarrhea prevalence and increased weight gain during weeks 17–26 in low-birth-weight infants.

Trust comment: Randomized trial with three arms and active morbidity surveillance; good internal validity though effect sizes modest.

Study Details

PMID:9701155
Participants:205
Impact:increased in 5 mg Zn group (P = 0.024)
Trust score:4/5

NIH-CPIS (symptom/quality-of-life score)

1 evidences

Adding organic zinc after antibiotics improved symptom scores and reduced urethral pressure in chronic bacterial prostatitis patients.

Trust comment: Randomized clinical study but small sample and limited methodological detail reported in abstract.

Study Details

PMID:15190832
Participants:61
Impact:markedly decreased after zinc treatment versus non-zinc (P < 0.05)
Trust score:3/5

maximum urethra closure pressure (MUCP)

1 evidences

Adding organic zinc after antibiotics improved symptom scores and reduced urethral pressure in chronic bacterial prostatitis patients.

Trust comment: Randomized clinical study but small sample and limited methodological detail reported in abstract.

Study Details

PMID:15190832
Participants:61
Impact:markedly decreased after zinc treatment versus non-zinc (P < 0.05)
Trust score:3/5

mental development (Bayley)

1 evidences

Short-course zinc (5 mg/d for 8 weeks) did not change Bayley mental/psychomotor scores but improved some behavioral ratings (responsiveness).

Trust comment: Prospective double-blind, part-randomized trial with good follow-up but partial randomization and attrition reduce confidence.

Study Details

PMID:9537309
Participants:138
Impact:no significant change between groups
Trust score:3/5

psychomotor development (Bayley)

1 evidences

Short-course zinc (5 mg/d for 8 weeks) did not change Bayley mental/psychomotor scores but improved some behavioral ratings (responsiveness).

Trust comment: Prospective double-blind, part-randomized trial with good follow-up but partial randomization and attrition reduce confidence.

Study Details

PMID:9537309
Participants:138
Impact:no significant change between groups
Trust score:3/5

behavior — responsiveness

1 evidences

Short-course zinc (5 mg/d for 8 weeks) did not change Bayley mental/psychomotor scores but improved some behavioral ratings (responsiveness).

Trust comment: Prospective double-blind, part-randomized trial with good follow-up but partial randomization and attrition reduce confidence.

Study Details

PMID:9537309
Participants:138
Impact:higher ratings in 5 mg Zn group at 12 months (P = 0.042)
Trust score:3/5

height increment (boys)

1 evidences

Daily 5 mg zinc for 6 months increased weight gain and boys' height and reduced stunting in children with low linear growth.

Trust comment: Community randomized controlled trial with measured anthropometric outcomes and reasonable follow-up, though subgroup effects noted.

Study Details

PMID:18956153
Participants:85
Impact:significantly increased (P = 0.001)
Trust score:4/5

stunting rate

1 evidences

Daily 5 mg zinc for 6 months increased weight gain and boys' height and reduced stunting in children with low linear growth.

Trust comment: Community randomized controlled trial with measured anthropometric outcomes and reasonable follow-up, though subgroup effects noted.

Study Details

PMID:18956153
Participants:85
Impact:decreased from 26.7% to 2.5% in zinc group (P = 0.01)
Trust score:4/5

LDL cholesterol

1 evidences

Randomized double-blind placebo-controlled trial in 60 adults with moderate hypercholesterolemia; an 8-week nutraceutical containing bergamot/artichoke/Q10 and zinc improved lipids, inflammation markers and endothelial reactivity versus placebo.

Trust comment: Randomized, double-blind placebo-controlled trial with complete follow-up (n=60); modest sample size limits precision but design is strong.

Study Details

PMID:35631240
Participants:60
Impact:significant decrease vs placebo
Trust score:4/5

serum anti-CTB IgA and IgG response

1 evidences

Small trial in zinc-replete adult volunteers testing oral zinc during cholera vaccination; zinc altered systemic and mucosal immune responses.

Trust comment: Controlled human study but small sample (n=30) and conducted in zinc-replete adults, limiting generalizability.

Study Details

PMID:12819076
Participants:30
Impact:reduced (median ~13-fold lower over day0–30)
Trust score:3/5

serum vibriocidal response

1 evidences

Small trial in zinc-replete adult volunteers testing oral zinc during cholera vaccination; zinc altered systemic and mucosal immune responses.

Trust comment: Controlled human study but small sample (n=30) and conducted in zinc-replete adults, limiting generalizability.

Study Details

PMID:12819076
Participants:30
Impact:increased (≈6-fold after one dose, ≈4-fold after two doses)
Trust score:3/5

fecal anti-CTB IgA response

1 evidences

Small trial in zinc-replete adult volunteers testing oral zinc during cholera vaccination; zinc altered systemic and mucosal immune responses.

Trust comment: Controlled human study but small sample (n=30) and conducted in zinc-replete adults, limiting generalizability.

Study Details

PMID:12819076
Participants:30
Impact:increased (≈4-fold after two doses)
Trust score:3/5

CD4+ cell count

1 evidences

Clinical study in AZT-treated AIDS patients where oral zinc was added and associated with improved weight, CD4 counts and fewer some opportunistic infections.

Trust comment: Human clinical study with small groups and limited detail on randomization or blinding, but reports clinically relevant changes.

Study Details

PMID:8582783
Participants:57
Impact:increased or stabilized
Trust score:3/5

frequency of opportunistic infections (stage IV)

1 evidences

Clinical study in AZT-treated AIDS patients where oral zinc was added and associated with improved weight, CD4 counts and fewer some opportunistic infections.

Trust comment: Human clinical study with small groups and limited detail on randomization or blinding, but reports clinically relevant changes.

Study Details

PMID:8582783
Participants:57
Impact:reduced (11 vs 25 infections over 24 months in zinc-treated vs controls)
Trust score:3/5

Body weight

3 evidences

12-week randomized double-blind trial in overweight/obese women; zinc (30 mg/day) improved some cognitive tests and altered salivary biomarkers but did not change weight versus placebo.

Trust comment: Randomized double-blind RCT with appropriate measures but small sample and differential dropout that limit generalizability.

Study Details

PMID:37892471
Participants:32
Impact:−2.4 kg (intragroup change in Zn group, p=0.019)
Trust score:4/5

Giving small-quantity lipid-based nutrient supplements (with morbidity treatment) to 9–18 month old children increased weight and lean mass; adding extra zinc (in LNS or tablets) had no detectable effect on body composition.

Trust comment: Well-conducted cluster-randomized trial with objective deuterium dilution body-composition measures but limited sub-study size and adherence concerns may limit zinc-specific inferences.

Study Details

PMID:35829783
Participants:275
Impact:Intervention cohort gained +1.80 kg vs +1.57 kg in non-intervention cohort (change baseline→18 mo); additional zinc dose had no effect.
Trust score:4/5

Clinical study in AZT-treated AIDS patients where oral zinc was added and associated with improved weight, CD4 counts and fewer some opportunistic infections.

Trust comment: Human clinical study with small groups and limited detail on randomization or blinding, but reports clinically relevant changes.

Study Details

PMID:8582783
Participants:57
Impact:increased or stabilized
Trust score:3/5

stool volume

1 evidences

Randomized, double-blind, placebo-controlled trial in infants 1–6 months showing no benefit of zinc on diarrhea duration or stool volume.

Trust comment: Well-designed randomized controlled trial with adequate sample (n=275) showing null effects in young infants.

Study Details

PMID:16155274
Participants:275
Impact:no significant change
Trust score:4/5

proportion experiencing diarrhea / time to first episode

1 evidences

In children treated for acute diarrhea, 5 days of zinc was as effective as 10 days at preventing subsequent diarrhea over 3 months.

Trust comment: Large randomized, community double-blind trial with daily supervision and adequate follow-up; compares two zinc regimens rather than zinc vs no zinc.

Study Details

PMID:21147907
Participants:1622
Impact:no significant difference between groups during 90-d follow-up
Trust score:4/5

head circumference gain

1 evidences

Low birth weight infants given daily zinc had greater weight, length and head circumference gains by 6 months compared with placebo.

Trust comment: Randomized placebo-controlled trial with monthly anthropometry; moderate sample of completers but some attrition.

Study Details

PMID:21858548
Participants:76
Impact:greater head circumference increase: 8.7 ± 1.4 cm (zinc) vs 7.4 ± 1.5 cm (placebo) (P<0.001)
Trust score:4/5

magnesium balance

1 evidences

In postmenopausal women under controlled dietary conditions, a higher zinc intake reduced magnesium balance and altered markers of bone turnover.

Trust comment: Well-controlled metabolic dietary study in humans but small sample size limits generalizability.

Study Details

PMID:15116072
Participants:25
Impact:decreased magnesium balance via increased fecal and urinary Mg excretion with moderately high zinc (≈53 mg/day)
Trust score:4/5

urinary N-telopeptides (bone resorption)

1 evidences

In postmenopausal women under controlled dietary conditions, a higher zinc intake reduced magnesium balance and altered markers of bone turnover.

Trust comment: Well-controlled metabolic dietary study in humans but small sample size limits generalizability.

Study Details

PMID:15116072
Participants:25
Impact:increased urinary N-telopeptides during high-zinc period
Trust score:4/5

serum calcitonin

1 evidences

In postmenopausal women under controlled dietary conditions, a higher zinc intake reduced magnesium balance and altered markers of bone turnover.

Trust comment: Well-controlled metabolic dietary study in humans but small sample size limits generalizability.

Study Details

PMID:15116072
Participants:25
Impact:decreased serum calcitonin during high-zinc period
Trust score:4/5

serum IGF-I

1 evidences

Zinc raised serum IGF-I in infants with failure to thrive but did not produce measurable growth improvements over 12 weeks.

Trust comment: Randomized double-blind placebo-controlled design but small sample and short duration reduce power to detect growth changes.

Study Details

PMID:10725786
Participants:25
Impact:increased from 40.3 ± 7 ng/ml to 65 ± 8 ng/ml after 12 weeks of zinc (2 mg/kg/day) (P<0.05)
Trust score:3/5

growth (weight/length)

1 evidences

Zinc raised serum IGF-I in infants with failure to thrive but did not produce measurable growth improvements over 12 weeks.

Trust comment: Randomized double-blind placebo-controlled design but small sample and short duration reduce power to detect growth changes.

Study Details

PMID:10725786
Participants:25
Impact:no significant change in weight-for-age, length-for-age, or weight-for-length in zinc vs placebo
Trust score:3/5

neurodevelopmental test scores

1 evidences

Prenatal zinc supplementation (25 mg/day in second half of pregnancy) had no effect on children's mental or psychomotor test scores at age 5.

Trust comment: Large follow-up of a randomized maternal supplementation trial with standardized assessments; negative result is likely robust in this population.

Study Details

PMID:12791632
Participants:355
Impact:no difference in multiple standardized mental and psychomotor test scores at mean age 5.3 y (zinc vs placebo)
Trust score:4/5

plasma EC-SOD activity

1 evidences

In pregnant women, prenatal zinc supplementation did not change plasma extracellular superoxide dismutase (EC-SOD) activity.

Trust comment: Nested biomarker analysis from an RCT with moderate sample size; outcome negative and may reflect limited sensitivity of the marker.

Study Details

PMID:11437176
Participants:63
Impact:no change in EC-SOD activity with 25 mg/day zinc supplementation (no improvement as a marker of zinc nutriture)
Trust score:3/5

febrile response (temperature)

1 evidences

In acutely ill adults on parenteral nutrition, short-term parenteral zinc supplementation increased fever compared with no zinc.

Trust comment: Randomized double-blind trial but small and specific patient population (TPN with sepsis/pancreatitis) limits generalizability.

Study Details

PMID:9040547
Participants:44
Impact:significantly higher temperature in zinc group on day 3 of TPN (P=0.035)
Trust score:3/5

interleukin-6 and ceruloplasmin

1 evidences

In acutely ill adults on parenteral nutrition, short-term parenteral zinc supplementation increased fever compared with no zinc.

Trust comment: Randomized double-blind trial but small and specific patient population (TPN with sepsis/pancreatitis) limits generalizability.

Study Details

PMID:9040547
Participants:44
Impact:no significant differences in serum IL-6 or ceruloplasmin between zinc and control
Trust score:3/5

cold duration

1 evidences

Zinc nasal gel started within 24–48 h of cold onset shortened symptom duration and reduced symptom severity compared with placebo.

Trust comment: Randomized, double-blind placebo-controlled trial but relatively small sample (n=80) limits precision.

Study Details

PMID:12509647
Participants:80
Impact:median −1.7 days (4.3 vs 6.0 days; ~28% shorter; p=0.002)
Trust score:4/5

ex-vivo IFN-γ

1 evidences

Daily zinc for 4 months increased cellular immune responses (IFN-γ) and modified vitamin A effects on salivary IgA, especially in younger and underweight children.

Trust comment: Large randomized design with immune endpoints measured in randomized subsets; subset measurement limits generalizability of immune outcomes.

Study Details

PMID:33377367
Participants:826
Impact:increased (greatest in boys, <3.5 y, normal weight, low baseline retinol)
Trust score:4/5

salivary IgA (post-vitamin A)

1 evidences

Daily zinc for 4 months increased cellular immune responses (IFN-γ) and modified vitamin A effects on salivary IgA, especially in younger and underweight children.

Trust comment: Large randomized design with immune endpoints measured in randomized subsets; subset measurement limits generalizability of immune outcomes.

Study Details

PMID:33377367
Participants:826
Impact:modified/increased in younger and underweight children with zinc
Trust score:4/5

skin zinc

1 evidences

IV trace element supplementation (including zinc) in major burn patients raised plasma and skin zinc and was associated with fewer infections and improved wound-healing outcomes.

Trust comment: Prospective randomized trial but small (n=21) and used combined trace element infusion (zinc + others), limiting attribution to zinc alone.

Study Details

PMID:17490965
Participants:21
Impact:increased by day 20 (p=0.04)
Trust score:3/5

infections (30 d)

1 evidences

IV trace element supplementation (including zinc) in major burn patients raised plasma and skin zinc and was associated with fewer infections and improved wound-healing outcomes.

Trust comment: Prospective randomized trial but small (n=21) and used combined trace element infusion (zinc + others), limiting attribution to zinc alone.

Study Details

PMID:17490965
Participants:21
Impact:median 2 vs 4 infections per patient (TE vs control; p=0.015)
Trust score:3/5

wound healing (regrafting)

1 evidences

IV trace element supplementation (including zinc) in major burn patients raised plasma and skin zinc and was associated with fewer infections and improved wound-healing outcomes.

Trust comment: Prospective randomized trial but small (n=21) and used combined trace element infusion (zinc + others), limiting attribution to zinc alone.

Study Details

PMID:17490965
Participants:21
Impact:reduced regrafting requirements (improved wound healing; p=0.02)
Trust score:3/5

age at first walking

1 evidences

Daily zinc (10 mg) did not change the mean age at first walking unassisted compared with placebo in this large community trial.

Trust comment: Large community-based, cluster-randomized placebo-controlled trial with robust sample and appropriate adjustments; null effect for walking milestone.

Study Details

PMID:20484548
Participants:1775
Impact:no difference (mean ~444 days; zinc vs placebo = 444 vs 444 d)
Trust score:5/5

gingival severity index

1 evidences

Using a zinc+arginine toothpaste twice daily for 6 months reduced dental plaque and gingivitis more than a regular fluoride toothpaste.

Trust comment: Randomized double-blind clinical trial with 100 enrolled and 96 completers showing consistent, statistically significant effects, though industry product involvement noted.

Study Details

PMID:30620869
Participants:96
Impact:-56.6% (6 months vs control)
Trust score:4/5

LDL-C

1 evidences

In coronary artery disease patients, 10 mg rosuvastatin reduced lipids and hs-CRP; adding zinc+selenium did not further change lipid profile, antioxidant enzymes, or mineral status.

Trust comment: Double-blind randomized controlled trial, registered and clinically measured endpoints; moderate-sized but may be underpowered for small effects.

Study Details

PMID:25785441
Participants:76
Impact:no additional change vs placebo (δ = 6.5 mg/dL; 95% CI −13.5–26.5; P=0.36)
Trust score:4/5

antioxidant enzyme activity (GPx/SOD)

1 evidences

In coronary artery disease patients, 10 mg rosuvastatin reduced lipids and hs-CRP; adding zinc+selenium did not further change lipid profile, antioxidant enzymes, or mineral status.

Trust comment: Double-blind randomized controlled trial, registered and clinically measured endpoints; moderate-sized but may be underpowered for small effects.

Study Details

PMID:25785441
Participants:76
Impact:no significant change vs placebo (δs non-significant; P>0.33)
Trust score:4/5

plasma/erythrocyte zinc and selenium

1 evidences

In coronary artery disease patients, 10 mg rosuvastatin reduced lipids and hs-CRP; adding zinc+selenium did not further change lipid profile, antioxidant enzymes, or mineral status.

Trust comment: Double-blind randomized controlled trial, registered and clinically measured endpoints; moderate-sized but may be underpowered for small effects.

Study Details

PMID:25785441
Participants:76
Impact:no significant change vs placebo (δs non-significant; P>0.14–0.63)
Trust score:4/5

NLRP3 expression

1 evidences

Zinc gluconate 30 mg/day for 12 weeks reduced inflammasome gene expression and improved genital ulcers in Behçet's disease patients compared with placebo.

Trust comment: Randomized double-blind placebo-controlled trial with clear biochemical and clinical endpoints but relatively small sample size.

Study Details

PMID:35561480
Participants:50
Impact:decreased (baseline-adjusted P=0.046; adjusted P=0.032)
Trust score:4/5

caspase-1 expression

1 evidences

Zinc gluconate 30 mg/day for 12 weeks reduced inflammasome gene expression and improved genital ulcers in Behçet's disease patients compared with placebo.

Trust comment: Randomized double-blind placebo-controlled trial with clear biochemical and clinical endpoints but relatively small sample size.

Study Details

PMID:35561480
Participants:50
Impact:decreased (baseline-adjusted P=0.003; adjusted P=0.004)
Trust score:4/5

genital ulcer (clinical manifestation)

1 evidences

Zinc gluconate 30 mg/day for 12 weeks reduced inflammasome gene expression and improved genital ulcers in Behçet's disease patients compared with placebo.

Trust comment: Randomized double-blind placebo-controlled trial with clear biochemical and clinical endpoints but relatively small sample size.

Study Details

PMID:35561480
Participants:50
Impact:improved (P=0.019); IBDDAM NNT = 3 [1.7–8.5]
Trust score:4/5

time to recovery

1 evidences

In hospitalized children with acute diarrhea, replacing ORS with zinc-containing ORS did not reduce stool output or time to recovery compared with standard ORS, likely due to inadequate zinc intake after day 1.

Trust comment: Large double-masked randomized controlled trial in children with clear primary outcomes, though adherence/intake issues limited zinc dosing.

Study Details

PMID:21788757
Participants:500
Impact:no significant difference (hazard ratio 1.06; 95% CI 0.88–1.27)
Trust score:4/5

zinc intake from ORS

1 evidences

In hospitalized children with acute diarrhea, replacing ORS with zinc-containing ORS did not reduce stool output or time to recovery compared with standard ORS, likely due to inadequate zinc intake after day 1.

Trust comment: Large double-masked randomized controlled trial in children with clear primary outcomes, though adherence/intake issues limited zinc dosing.

Study Details

PMID:21788757
Participants:500
Impact:not sustained beyond day 1 (median intake fell markedly after day 1)
Trust score:4/5

time to resolution of vomiting

1 evidences

In children with rotavirus diarrhea, zinc alone or zinc plus Saccharomyces boulardii shortened diarrhea and hospital stay compared to rehydration alone.

Trust comment: Large randomized treatment-group study in children with clear clinical outcomes, though exact effect sizes not reported in text excerpt.

Study Details

PMID:21261786
Participants:480
Impact:decreased (significant in zinc+S. boulardii group vs some other groups)
Trust score:4/5

dental plaque

2 evidences

Brushing with an herbal toothpaste containing zinc for 6 months reduced plaque, gingival inflammation, and bleeding more than a fluoride-only toothpaste.

Trust comment: Randomized clinical trial with reasonable completion rate and clear reported outcomes, though formulations included multiple herbal ingredients alongside zinc.

Study Details

PMID:33866666
Participants:150
Impact:-23.5%
Trust score:4/5

A mouthrinse containing CPC + zinc lactate + fluoride reduced dental plaque and gingival inflammation more than essential-oil rinse or brushing alone over 6 weeks.

Trust comment: Randomized clinical trial with calibrated examiners and clear quantitative outcomes, moderate sample size.

Study Details

PMID:33358239
Participants:120
Impact:reduced: 21.4% vs EO and 31.4% vs control at 4 weeks; 26.7% vs EO and 44.8% vs control at 6 weeks
Trust score:4/5

gingival inflammation (Löe‑Silness index)

1 evidences

A mouthrinse containing CPC + zinc lactate + fluoride reduced dental plaque and gingival inflammation more than essential-oil rinse or brushing alone over 6 weeks.

Trust comment: Randomized clinical trial with calibrated examiners and clear quantitative outcomes, moderate sample size.

Study Details

PMID:33358239
Participants:120
Impact:reduced: 10.6% vs EO and 13.6% vs control at 4 weeks; 13.7% vs EO and 17.8% vs control at 6 weeks
Trust score:4/5

orientation-engagement

1 evidences

Weekly iron and zinc (together or individually) improved infant motor development and attention/orientation measures between 6 and 12 months.

Trust comment: Double-blind randomized trial with relevant developmental assessments, moderate sample and appropriate adjustments reported.

Study Details

PMID:15447897
Participants:221
Impact:improved (beneficial effect with iron and zinc individually and combined)
Trust score:4/5

serum folate concentration

2 evidences

Six months of zinc‑fortified rice increased serum zinc, lowered zinc deficiency prevalence, and (for NutriRice) increased serum folate in Cambodian schoolchildren.

Trust comment: Large double-blind cluster-RCT with biochemical outcomes and appropriate statistical methods; high external validity for similar settings.

Study Details

PMID:31756911
Participants:1667
Impact:+2.25 ng/mL (NutriRice vs placebo over 6 months)
Trust score:5/5

Zinc supplementation (50 mg/day for 8 weeks) increased circulating folate and decreased homocysteine but did not change vitamin B12 in postmenopausal women.

Trust comment: Small randomized trial with short duration and limited sample size; authors note need for larger studies to confirm findings.

Study Details

PMID:35149326
Participants:51
Impact:significant increase
Trust score:3/5

SARS-CoV-2 infection incidence

1 evidences

In this underpowered RCT, combined doxycycline + zinc prophylaxis was associated with fewer COVID-19 PCR-positive cases and higher Ct (lower viral load) compared with placebo.

Trust comment: Randomized double-blind design but prematurely stopped and underpowered (small sample vs planned), limiting robustness of conclusions.

Study Details

PMID:35724828
Participants:172
Impact:reduced: 8.5% (5/59) combined, 8.9% (5/56) doxy only, 24.6% (14/57) placebo (P=0.018)
Trust score:3/5

viral load (RT-PCR Ct)

1 evidences

In this underpowered RCT, combined doxycycline + zinc prophylaxis was associated with fewer COVID-19 PCR-positive cases and higher Ct (lower viral load) compared with placebo.

Trust comment: Randomized double-blind design but prematurely stopped and underpowered (small sample vs planned), limiting robustness of conclusions.

Study Details

PMID:35724828
Participants:172
Impact:higher mean Ct (lower inferred viral load) in combined therapy: 29.0 vs 22.8 (doxy) and 19.4 (placebo) (P<0.001)
Trust score:3/5

FT3 (free triiodothyronine)

1 evidences

In overweight/obese hypothyroid women, 12 weeks of zinc (alone or with selenium) modestly changed some thyroid hormone levels.

Trust comment: Randomized double-blind RCT with 68 participants and appropriate measures; some changes are within-group and between-group differences were limited.

Study Details

PMID:25758370
Participants:68
Impact:increase (significant in Zn groups)
Trust score:4/5

FT4 (free thyroxine)

1 evidences

In overweight/obese hypothyroid women, 12 weeks of zinc (alone or with selenium) modestly changed some thyroid hormone levels.

Trust comment: Randomized double-blind RCT with 68 participants and appropriate measures; some changes are within-group and between-group differences were limited.

Study Details

PMID:25758370
Participants:68
Impact:increase (significant within Zn+Se group)
Trust score:4/5

TSH (thyroid-stimulating hormone)

1 evidences

In overweight/obese hypothyroid women, 12 weeks of zinc (alone or with selenium) modestly changed some thyroid hormone levels.

Trust comment: Randomized double-blind RCT with 68 participants and appropriate measures; some changes are within-group and between-group differences were limited.

Study Details

PMID:25758370
Participants:68
Impact:decrease (significant within Zn+Se group)
Trust score:4/5

Relapse rate

1 evidences

In children with steroid-sensitive nephrotic syndrome, 12 months of zinc showed trends to fewer relapses and higher remission rates, especially in frequent relapsers.

Trust comment: Double-blind randomized trial in 81 children; subgroup (frequent relapsers) showed a statistically significant benefit though overall effects were trends.

Study Details

PMID:19347367
Participants:81
Impact:−20% overall (trend); −28% in frequent relapsers
Trust score:4/5

Sustained remission

1 evidences

In children with steroid-sensitive nephrotic syndrome, 12 months of zinc showed trends to fewer relapses and higher remission rates, especially in frequent relapsers.

Trust comment: Double-blind randomized trial in 81 children; subgroup (frequent relapsers) showed a statistically significant benefit though overall effects were trends.

Study Details

PMID:19347367
Participants:81
Impact:+17.2 percentage points overall (44.7% vs 27.5%); significantly higher in frequent relapsers (P=0.02)
Trust score:4/5

Zinc/copper ratio

1 evidences

Three months of curcumin increased serum zinc and the zinc/copper ratio and lowered serum copper in adults with β-thalassemia intermedia.

Trust comment: Small (n=30) randomized double-blind trial measuring mineral biomarkers; limited sample size reduces generalizability.

Study Details

PMID:33432439
Participants:30
Impact:increase (significant)
Trust score:3/5

urinary zinc (uZn)

1 evidences

In postmenopausal women, alendronate and calcitonin reduced urinary zinc excretion and bone turnover markers over 6 months, with alendronate showing earlier and larger effects.

Trust comment: Randomized placebo-controlled study with 135 participants and multiple timepoint measurements; clear biomarker changes support findings.

Study Details

PMID:15607319
Participants:135
Impact:decrease (~33% calcitonin; ~38% alendronate vs baseline at 6 months)
Trust score:4/5

Bone resorption marker (uNTx)

1 evidences

In postmenopausal women, alendronate and calcitonin reduced urinary zinc excretion and bone turnover markers over 6 months, with alendronate showing earlier and larger effects.

Trust comment: Randomized placebo-controlled study with 135 participants and multiple timepoint measurements; clear biomarker changes support findings.

Study Details

PMID:15607319
Participants:135
Impact:decrease (~44% calcitonin; ~53% alendronate vs baseline at 6 months)
Trust score:4/5

Bone formation marker (osteocalcin, sOC)

1 evidences

In postmenopausal women, alendronate and calcitonin reduced urinary zinc excretion and bone turnover markers over 6 months, with alendronate showing earlier and larger effects.

Trust comment: Randomized placebo-controlled study with 135 participants and multiple timepoint measurements; clear biomarker changes support findings.

Study Details

PMID:15607319
Participants:135
Impact:decrease (~36% calcitonin; ~51% alendronate vs baseline at 6 months)
Trust score:4/5

Shigellacidal antibody response (seroconversion)

1 evidences

In children with shigellosis, 14 days of adjunct zinc increased serum zinc, improved antibody seroconversion and increased circulating B-cell/plasma-cell proportions.

Trust comment: Double-blind placebo-controlled trial in malnourished children showing immunologic improvements with zinc adjunct therapy.

Study Details

PMID:15699240
Participants:56
Impact:higher proportion achieving ≥4-fold rise (P<0.03)
Trust score:4/5

Circulating B lymphocytes and plasma cells (CD20+, CD20+CD38+)

1 evidences

In children with shigellosis, 14 days of adjunct zinc increased serum zinc, improved antibody seroconversion and increased circulating B-cell/plasma-cell proportions.

Trust comment: Double-blind placebo-controlled trial in malnourished children showing immunologic improvements with zinc adjunct therapy.

Study Details

PMID:15699240
Participants:56
Impact:increase (higher proportions on day 7, P<0.007)
Trust score:4/5

Nosocomial pneumonia rate

1 evidences

In severely burned adults, IV supplementation with selenium, copper, and zinc reduced nosocomial pneumonia and VAP, shortened antibiotic days and ICU length of stay normalized per %BSA.

Trust comment: Aggregate of two double-blind randomized trials (n=41); strong, significant clinical effects but small sample and combined intervention (multiple trace elements) limit attribution to zinc alone.

Study Details

PMID:17081282
Participants:41
Impact:decrease (mean 0.33 vs 1.55 episodes per patient, P<0.001)
Trust score:4/5

Ventilator-associated pneumonia (VAP)

1 evidences

In severely burned adults, IV supplementation with selenium, copper, and zinc reduced nosocomial pneumonia and VAP, shortened antibiotic days and ICU length of stay normalized per %BSA.

Trust comment: Aggregate of two double-blind randomized trials (n=41); strong, significant clinical effects but small sample and combined intervention (multiple trace elements) limit attribution to zinc alone.

Study Details

PMID:17081282
Participants:41
Impact:decrease (significantly less frequent, P=0.001)
Trust score:4/5

Days of antibiotherapy / ICU length of stay (normalized)

1 evidences

In severely burned adults, IV supplementation with selenium, copper, and zinc reduced nosocomial pneumonia and VAP, shortened antibiotic days and ICU length of stay normalized per %BSA.

Trust comment: Aggregate of two double-blind randomized trials (n=41); strong, significant clinical effects but small sample and combined intervention (multiple trace elements) limit attribution to zinc alone.

Study Details

PMID:17081282
Participants:41
Impact:fewer antibiotic days (P=0.021) and shorter ICU stay per %BSA (median 0.63 vs 0.99 days/%BSA, P=0.002)
Trust score:4/5

oral mucositis severity

1 evidences

Topical zinc (and improvised zinc mix) applied during chemo/radiation reduced severity of oral mucositis versus standard care.

Trust comment: Randomized study with clinically assessed outcome but moderate sample size and subjective grading.

Study Details

PMID:32350185
Participants:75
Impact:decreased severity (statistically significant vs control, p=0.037)
Trust score:4/5

improvised zinc vs zinc oxide

1 evidences

Topical zinc (and improvised zinc mix) applied during chemo/radiation reduced severity of oral mucositis versus standard care.

Trust comment: Randomized study with clinically assessed outcome but moderate sample size and subjective grading.

Study Details

PMID:32350185
Participants:75
Impact:improvised zinc associated with less mucositis at days 28 and 35 (p=0.029, p=0.013)
Trust score:4/5

plasma zinc / zinc status

2 evidences

Different modes/amounts of oral iron did not change zinc absorption, zinc status, or growth in iron-sufficient infants.

Trust comment: Randomized trial with isotopic measures and objective endpoints, clear null results.

Study Details

PMID:27546308
Participants:72
Impact:no change
Trust score:4/5

In healthy breastfed infants, prior iron supplementation did not change zinc absorption or plasma zinc between 6 and 9 months.

Trust comment: Small sample but uses stable isotope absorption measures and objective endpoints; results consistent and specific.

Study Details

PMID:19056575
Participants:25
Impact:no correlation with zinc absorption; no change observed
Trust score:4/5

maternal viral load

1 evidences

Daily 25 mg zinc in HIV-positive pregnant women did not change viral load or early HIV transmission but was linked to more maternal wasting.

Trust comment: Large double-blind randomized trial with clinically relevant endpoints and clear effect estimates including harm.

Study Details

PMID:16452912
Participants:400
Impact:no change
Trust score:5/5

early mother-to-child transmission (MTCT)

1 evidences

Daily 25 mg zinc in HIV-positive pregnant women did not change viral load or early HIV transmission but was linked to more maternal wasting.

Trust comment: Large double-blind randomized trial with clinically relevant endpoints and clear effect estimates including harm.

Study Details

PMID:16452912
Participants:400
Impact:no change
Trust score:5/5

wasting (MUAC <22 cm)

1 evidences

Daily 25 mg zinc in HIV-positive pregnant women did not change viral load or early HIV transmission but was linked to more maternal wasting.

Trust comment: Large double-blind randomized trial with clinically relevant endpoints and clear effect estimates including harm.

Study Details

PMID:16452912
Participants:400
Impact:increased risk (RR=2.7, 95% CI 1.1–6.4, P=0.03); MUAC decline ≈ -4 mm in 2nd trimester
Trust score:5/5

CD19 cell percentage

1 evidences

In hemodialysis patients zinc increased serum zinc and some B-cell marker levels, but did not produce a clear between-group improvement in vaccine antibody response.

Trust comment: Small randomized sample with objective labs but limited power and mixed within/between-group results.

Study Details

PMID:9684909
Participants:37
Impact:increased in supplemented patients (p<0.05)
Trust score:3/5

influenza vaccine antibody response

1 evidences

In hemodialysis patients zinc increased serum zinc and some B-cell marker levels, but did not produce a clear between-group improvement in vaccine antibody response.

Trust comment: Small randomized sample with objective labs but limited power and mixed within/between-group results.

Study Details

PMID:9684909
Participants:37
Impact:within-group rise in supplemented patients but no significant improvement versus hemodialysis placebo group
Trust score:3/5

feeding intolerance

1 evidences

Higher-dose zinc in very low birth weight infants reduced feeding intolerance, necrotizing enterocolitis, and late-onset sepsis episodes versus control.

Trust comment: Prospective randomized trial with clinically important endpoints and adequate sample size, though single study.

Study Details

PMID:37939725
Participants:195
Impact:decreased (47.4% vs 65.3% in control, p=0.012)
Trust score:4/5

necrotizing enterocolitis (NEC)

1 evidences

Higher-dose zinc in very low birth weight infants reduced feeding intolerance, necrotizing enterocolitis, and late-onset sepsis episodes versus control.

Trust comment: Prospective randomized trial with clinically important endpoints and adequate sample size, though single study.

Study Details

PMID:37939725
Participants:195
Impact:decreased (1% vs 11.2% in control, p=0.003)
Trust score:4/5

late-onset sepsis (LOS)

1 evidences

Higher-dose zinc in very low birth weight infants reduced feeding intolerance, necrotizing enterocolitis, and late-onset sepsis episodes versus control.

Trust comment: Prospective randomized trial with clinically important endpoints and adequate sample size, though single study.

Study Details

PMID:37939725
Participants:195
Impact:fewer culture-proven LOS episodes (p=0.041); clinical sepsis also lower (p=0.029)
Trust score:4/5

RBC metallothionein (RBCMT)

1 evidences

RBC metallothionein rose during pregnancy but did not reliably reflect changes in zinc status from supplementation; RBC zinc at 36 wk differed by supplement.

Trust comment: Nested analysis from a controlled trial with measured biomarkers but limited to selected subset.

Study Details

PMID:18602250
Participants:158
Impact:increased during pregnancy but not responsive to zinc supplementation
Trust score:4/5

RBC zinc at 36 weeks

1 evidences

RBC metallothionein rose during pregnancy but did not reliably reflect changes in zinc status from supplementation; RBC zinc at 36 wk differed by supplement.

Trust comment: Nested analysis from a controlled trial with measured biomarkers but limited to selected subset.

Study Details

PMID:18602250
Participants:158
Impact:differed by supplement type (higher with zinc, P<0.05)
Trust score:4/5

FADS2 activity (linoleic→γ-linolenic acid)

1 evidences

In healthy adult men, consuming zinc-biofortified wheat (+1.6 mg Zn/day) did not change plasma zinc but altered zinc-sensitive fatty-acid desaturase activities (FADS2 up, FADS1 down); antioxidant and DNA damage markers unchanged.

Trust comment: Controlled randomized feeding trial with objective biomarkers but small sample (n=36) — well-controlled but limited power for broader endpoints.

Study Details

PMID:34036355
Participants:36
Impact:Increased from 0.020 to 0.025 (+0.005 absolute, ≈+25%; P=0.02)
Trust score:4/5

FADS1 activity (dihomo-γ-linolenic→arachidonic acid)

1 evidences

In healthy adult men, consuming zinc-biofortified wheat (+1.6 mg Zn/day) did not change plasma zinc but altered zinc-sensitive fatty-acid desaturase activities (FADS2 up, FADS1 down); antioxidant and DNA damage markers unchanged.

Trust comment: Controlled randomized feeding trial with objective biomarkers but small sample (n=36) — well-controlled but limited power for broader endpoints.

Study Details

PMID:34036355
Participants:36
Impact:Decreased from 6.37 to 5.53 (−0.84, ≈−13%; P=0.01)
Trust score:4/5

full-scale IQ

1 evidences

Follow-up of children given iron, zinc, both or placebo in infancy found no long-term differences in IQ, Raven scores, or school performance at age 9 years.

Trust comment: Long-term follow-up of a randomized infant supplementation trial with high retention (92%); robust sample but no cognitive benefit detected.

Study Details

PMID:21270383
Participants:560
Impact:No significant difference between supplementation groups at 9 y
Trust score:4/5

Raven's Colored Progressive Matrices score

1 evidences

Follow-up of children given iron, zinc, both or placebo in infancy found no long-term differences in IQ, Raven scores, or school performance at age 9 years.

Trust comment: Long-term follow-up of a randomized infant supplementation trial with high retention (92%); robust sample but no cognitive benefit detected.

Study Details

PMID:21270383
Participants:560
Impact:No significant difference between groups
Trust score:4/5

school performance tests

1 evidences

Follow-up of children given iron, zinc, both or placebo in infancy found no long-term differences in IQ, Raven scores, or school performance at age 9 years.

Trust comment: Long-term follow-up of a randomized infant supplementation trial with high retention (92%); robust sample but no cognitive benefit detected.

Study Details

PMID:21270383
Participants:560
Impact:No significant difference between groups
Trust score:4/5

fetal femur diaphysis length

1 evidences

Prenatal supplementation including 25 mg zinc increased fetal femur diaphysis length measured by ultrasound (statistically significant), with no effects on other fetal measurements.

Trust comment: Double-masked randomized trial in pregnant women with repeated ultrasound measures; observed specific positive effect on fetal femur length.

Study Details

PMID:15113721
Participants:242
Impact:Increased in zinc-supplemented group (P<0.05); ~+0.25 SD shift at term
Trust score:4/5

fetal head circumference

1 evidences

Prenatal supplementation including 25 mg zinc increased fetal femur diaphysis length measured by ultrasound (statistically significant), with no effects on other fetal measurements.

Trust comment: Double-masked randomized trial in pregnant women with repeated ultrasound measures; observed specific positive effect on fetal femur length.

Study Details

PMID:15113721
Participants:242
Impact:No significant difference by supplement type
Trust score:4/5

fetal abdominal circumference

1 evidences

Prenatal supplementation including 25 mg zinc increased fetal femur diaphysis length measured by ultrasound (statistically significant), with no effects on other fetal measurements.

Trust comment: Double-masked randomized trial in pregnant women with repeated ultrasound measures; observed specific positive effect on fetal femur length.

Study Details

PMID:15113721
Participants:242
Impact:No significant difference by supplement type
Trust score:4/5

3-year overall survival

1 evidences

In patients receiving radiotherapy for head and neck cancer, overall and disease-free 3-year survival did not differ with zinc supplementation, but local-free survival showed a marginal improvement overall and a significant benefit in the subgroup with stage III–IV disease receiving concurrent chemoradiotherapy.

Trust comment: Double-blind randomized study with modest sample size; overall survival unchanged, subgroup showed significant benefit — result may need confirmation and longer follow-up.

Study Details

PMID:17980503
Participants:100
Impact:No significant difference between zinc and placebo groups (P=0.19)
Trust score:3/5

3-year local-free survival (overall)

1 evidences

In patients receiving radiotherapy for head and neck cancer, overall and disease-free 3-year survival did not differ with zinc supplementation, but local-free survival showed a marginal improvement overall and a significant benefit in the subgroup with stage III–IV disease receiving concurrent chemoradiotherapy.

Trust comment: Double-blind randomized study with modest sample size; overall survival unchanged, subgroup showed significant benefit — result may need confirmation and longer follow-up.

Study Details

PMID:17980503
Participants:100
Impact:Marginally better in zinc group (P=0.092)
Trust score:3/5

3-year local-free survival (Stages III–IV with concurrent chemoradiotherapy)

1 evidences

In patients receiving radiotherapy for head and neck cancer, overall and disease-free 3-year survival did not differ with zinc supplementation, but local-free survival showed a marginal improvement overall and a significant benefit in the subgroup with stage III–IV disease receiving concurrent chemoradiotherapy.

Trust comment: Double-blind randomized study with modest sample size; overall survival unchanged, subgroup showed significant benefit — result may need confirmation and longer follow-up.

Study Details

PMID:17980503
Participants:100
Impact:Significantly better with zinc in this subgroup (P=0.003)
Trust score:3/5

gustatory function

1 evidences

Zinc gluconate improved taste function and mood in patients with idiopathic dysgeusia.

Trust comment: Randomized clinical trial with clear significant outcomes but moderate sample size (n=50).

Study Details

PMID:15615872
Participants:50
Impact:significant improvement (p < 0.001)
Trust score:4/5

dysgeusia severity

1 evidences

Zinc gluconate improved taste function and mood in patients with idiopathic dysgeusia.

Trust comment: Randomized clinical trial with clear significant outcomes but moderate sample size (n=50).

Study Details

PMID:15615872
Participants:50
Impact:reduced severity (p < 0.05)
Trust score:4/5

depression severity (mood/BDI)

1 evidences

Zinc gluconate improved taste function and mood in patients with idiopathic dysgeusia.

Trust comment: Randomized clinical trial with clear significant outcomes but moderate sample size (n=50).

Study Details

PMID:15615872
Participants:50
Impact:reduced depressive symptoms (p < 0.05)
Trust score:4/5

physician global acne improvement

1 evidences

Topical erythromycin/zinc solution was less effective than benzoyl peroxide/erythromycin gel for acne over 10 weeks.

Trust comment: Randomized 10-week trial with objective measures but limited to topical comparative setting and modest size.

Study Details

PMID:9068739
Participants:72
Impact:less improvement vs benzoyl peroxide/erythromycin (P ≤ 0.05)
Trust score:3/5

inflammatory lesion count

2 evidences

Topical erythromycin/zinc solution was less effective than benzoyl peroxide/erythromycin gel for acne over 10 weeks.

Trust comment: Randomized 10-week trial with objective measures but limited to topical comparative setting and modest size.

Study Details

PMID:9068739
Participants:72
Impact:smaller reduction vs comparator (P ≤ 0.005)
Trust score:3/5

Two zinc gluconate dosing regimens (with or without loading dose) showed no difference in inflammatory lesion outcomes over 3 months.

Trust comment: Double-blind clinical trial but small sample and comparison was between two zinc regimens (no placebo control reported here).

Study Details

PMID:10846252
Participants:67
Impact:No significant difference between regimens (loading vs constant) over 3 months
Trust score:3/5

comedone count

1 evidences

Topical erythromycin/zinc solution was less effective than benzoyl peroxide/erythromycin gel for acne over 10 weeks.

Trust comment: Randomized 10-week trial with objective measures but limited to topical comparative setting and modest size.

Study Details

PMID:9068739
Participants:72
Impact:smaller reduction vs comparator (P ≤ 0.001)
Trust score:3/5

Serum retinol

1 evidences

A 6-month multi-micronutrient beverage increased serum vitamin A and zinc in Nigerian schoolchildren.

Trust comment: Large double-blind, placebo-controlled school-based RCT with biochemical endpoints and high completion.

Study Details

PMID:21677073
Participants:534
Impact:+0.10 ± 0.02 μmol/L (micronutrient) vs +0.02 ± 0.02 μmol/L (control); p = 0.016
Trust score:4/5

self-reported vomiting

1 evidences

A 6-month multi-micronutrient beverage increased serum vitamin A and zinc in Nigerian schoolchildren.

Trust comment: Large double-blind, placebo-controlled school-based RCT with biochemical endpoints and high completion.

Study Details

PMID:21677073
Participants:534
Impact:higher prevalence trend in micronutrient group (21% vs 14%; p = 0.06)
Trust score:4/5

olfactory recovery time

1 evidences

In COVID-19 patients with smell loss, zinc therapy shortened smell recovery time but did not change overall illness recovery.

Trust comment: Prospective randomized allocation for smell therapy with clear effect on smell recovery but single-center and likely unblinded.

Study Details

PMID:33409924
Participants:134
Impact:median 7 days with zinc vs 18 days without; p < 0.001
Trust score:3/5

overall COVID-19 recovery duration

1 evidences

In COVID-19 patients with smell loss, zinc therapy shortened smell recovery time but did not change overall illness recovery.

Trust comment: Prospective randomized allocation for smell therapy with clear effect on smell recovery but single-center and likely unblinded.

Study Details

PMID:33409924
Participants:134
Impact:no significant difference (median ~12 days both groups; p > 0.05)
Trust score:3/5

serum zinc vs olfactory dysfunction

1 evidences

In COVID-19 patients with smell loss, zinc therapy shortened smell recovery time but did not change overall illness recovery.

Trust comment: Prospective randomized allocation for smell therapy with clear effect on smell recovery but single-center and likely unblinded.

Study Details

PMID:33409924
Participants:134
Impact:lower mean zinc in anosmia/hyposmia vs no dysfunction but difference not statistically significant (p > 0.05)
Trust score:3/5

sexual function (FSFI overall score)

1 evidences

Zinc supplementation in zinc-insufficient postmenopausal women raised testosterone and improved sexual function scores.

Trust comment: Randomized trial with clear reported improvements but some reporting inconsistencies and modest sample size.

Study Details

PMID:34311679
Participants:116
Impact:significant improvement in domains and overall FSFI (p < 0.001)
Trust score:3/5

testosterone level

1 evidences

Zinc supplementation in zinc-insufficient postmenopausal women raised testosterone and improved sexual function scores.

Trust comment: Randomized trial with clear reported improvements but some reporting inconsistencies and modest sample size.

Study Details

PMID:34311679
Participants:116
Impact:significant increase vs control (reported as significant)
Trust score:3/5

Hemoglobin / hematocrit

1 evidences

Zinc supplementation in zinc-insufficient postmenopausal women raised testosterone and improved sexual function scores.

Trust comment: Randomized trial with clear reported improvements but some reporting inconsistencies and modest sample size.

Study Details

PMID:34311679
Participants:116
Impact:measured but no clear significant change reported
Trust score:3/5

psoriasis sign composite score

1 evidences

Adding 0.25% zinc pyrithione spray provided no additional benefit over clobetasol foam alone for plaque psoriasis.

Trust comment: Small randomized split-body trial with clear negative result but limited sample size.

Study Details

PMID:12833013
Participants:24
Impact:no additional improvement with zinc (mean decline 3.5 vs 3.3; P = 0.5)
Trust score:3/5

respiratory-related illness incidence

1 evidences

School lunch seasoning fortified with multiple micronutrients (including 50 μg iodine per serving) reduced respiratory and diarrheal morbidity and slightly improved a visual recall test, but did not change growth.

Trust comment: Large cluster RCT with meaningful morbidity and short-term cognitive endpoints, but fortification included multiple micronutrients.

Study Details

PMID:18541560
Participants:569
Impact:reduced (rate ratio 0.83; 95% CI: 0.73, 0.94)
Trust score:4/5

visual recall (short-term cognitive)

1 evidences

School lunch seasoning fortified with multiple micronutrients (including 50 μg iodine per serving) reduced respiratory and diarrheal morbidity and slightly improved a visual recall test, but did not change growth.

Trust comment: Large cluster RCT with meaningful morbidity and short-term cognitive endpoints, but fortification included multiple micronutrients.

Study Details

PMID:18541560
Participants:569
Impact:improved by +0.5 items recalled (95% CI: 0.1, 0.9)
Trust score:4/5

malnutrition prevalence (BMI)

1 evidences

Randomized workplace nutrition intervention providing oral nutrition supplements (multi‑vitamin/mineral formula including minerals) plus education vs education alone in female workers; intervention improved biochemical micronutrient markers including serum zinc, iron, and total serum calcium and reduced micronutrient deficiency prevalence.

Trust comment: Large randomized trial with objective biochemical outcomes, but use of a multinutrient ONS means effects cannot be attributed to zinc alone.

Study Details

PMID:38684383
Participants:500
Impact:no change in intervention (control increased from 15.6% to 21.3%, +5.7 percentage points)
Trust score:4/5

diarrhoea incidence in stunted HIV‑uninfected children

1 evidences

Randomized trial in infants showing zinc (with vitamin A or in MMN) reduced diarrhoea incidence in stunted HIV‑uninfected children but not overall; possible increased persistent/severe diarrhoea in HIV‑infected children.

Trust comment: Large randomized, double‑blind community trial with robust analyses and sensitivity checks, though subgroup findings require cautious interpretation.

Study Details

PMID:19174830
Participants:337
Impact:−48% (RR 0.52 vs vitamin A alone)
Trust score:4/5

persistent/severe diarrhoea in HIV‑infected children

1 evidences

Randomized trial in infants showing zinc (with vitamin A or in MMN) reduced diarrhoea incidence in stunted HIV‑uninfected children but not overall; possible increased persistent/severe diarrhoea in HIV‑infected children.

Trust comment: Large randomized, double‑blind community trial with robust analyses and sensitivity checks, though subgroup findings require cautious interpretation.

Study Details

PMID:19174830
Participants:337
Impact:increased (higher incidence in zinc or multiple micronutrient arms)
Trust score:4/5

overall diarrhoea incidence (all cohorts)

1 evidences

Randomized trial in infants showing zinc (with vitamin A or in MMN) reduced diarrhoea incidence in stunted HIV‑uninfected children but not overall; possible increased persistent/severe diarrhoea in HIV‑infected children.

Trust comment: Large randomized, double‑blind community trial with robust analyses and sensitivity checks, though subgroup findings require cautious interpretation.

Study Details

PMID:19174830
Participants:337
Impact:no difference between treatment groups
Trust score:4/5

plasma DHA

1 evidences

Cluster RCT nested analysis: modest increase in dietary zinc from biofortified wheat produced biochemical shifts (DHA and some pro‑inflammatory oxylipins) but intervention effects were not significant after multiple‑comparison correction.

Trust comment: Well‑designed cluster RCT with adequate sample and blinded conduct, but per‑protocol analysis and lack of FDR‑significant intervention effects reduce confidence in causal claims.

Study Details

PMID:39770887
Participants:399
Impact:greater increase in zinc‑biofortified wheat group (>20% greater increase vs control; not significant after FDR correction)
Trust score:4/5

pro‑inflammatory oxylipins (5‑HETE, 15‑HETE, 11‑HETE, 9‑HETE)

1 evidences

Cluster RCT nested analysis: modest increase in dietary zinc from biofortified wheat produced biochemical shifts (DHA and some pro‑inflammatory oxylipins) but intervention effects were not significant after multiple‑comparison correction.

Trust comment: Well‑designed cluster RCT with adequate sample and blinded conduct, but per‑protocol analysis and lack of FDR‑significant intervention effects reduce confidence in causal claims.

Study Details

PMID:39770887
Participants:399
Impact:decreased over 25 weeks (group×time observed but reductions occurred in both groups; no FDR‑significant intervention effects)
Trust score:4/5

fatty‑acid desaturation indices

1 evidences

Cluster RCT nested analysis: modest increase in dietary zinc from biofortified wheat produced biochemical shifts (DHA and some pro‑inflammatory oxylipins) but intervention effects were not significant after multiple‑comparison correction.

Trust comment: Well‑designed cluster RCT with adequate sample and blinded conduct, but per‑protocol analysis and lack of FDR‑significant intervention effects reduce confidence in causal claims.

Study Details

PMID:39770887
Participants:399
Impact:no significant intervention effect detected
Trust score:4/5

Child–Pugh score

1 evidences

Randomized trial in non‑alcoholic cirrhosis showed 90 days of 50 mg zinc daily improved Child‑Pugh score and lowered copper and creatinine versus placebo.

Trust comment: Randomized, placebo‑controlled trial with clear biochemical outcomes but modest size and per‑protocol analysis limit generalizability.

Study Details

PMID:22827782
Participants:60
Impact:improved (6.56 ± 0.21 to 5.72 ± 0.22; −0.84 points)
Trust score:3/5

serum creatinine

1 evidences

Randomized trial in non‑alcoholic cirrhosis showed 90 days of 50 mg zinc daily improved Child‑Pugh score and lowered copper and creatinine versus placebo.

Trust comment: Randomized, placebo‑controlled trial with clear biochemical outcomes but modest size and per‑protocol analysis limit generalizability.

Study Details

PMID:22827782
Participants:60
Impact:decreased (P < 0.0001)
Trust score:3/5

offspring cardiometabolic profile (BP, lipids, insulin resistance, anthropometry)

1 evidences

Maternal zinc supplementation during pregnancy did not change offspring cardiometabolic risk markers (body size, blood pressure, lipids, insulin resistance) at 4.5 years.

Trust comment: Randomized clinical trial with reasonable sample size and long‑term follow‑up, producing null effects for these outcomes.

Study Details

PMID:27748235
Participants:242
Impact:no difference at 4.5 years
Trust score:4/5

PBMC proliferation

1 evidences

Randomized placebo-controlled supplement (45 mg/day zinc) for 60 days in patients with cutaneous leishmaniasis found no additional in vivo effect of zinc on measured cellular immune responses.

Trust comment: Small randomized trial with direct human data but limited sample size and short follow-up; outcomes reported objectively.

Study Details

PMID:25661338
Participants:29
Impact:no change vs placebo after 60 days
Trust score:3/5

IFN-γ production

1 evidences

Randomized placebo-controlled supplement (45 mg/day zinc) for 60 days in patients with cutaneous leishmaniasis found no additional in vivo effect of zinc on measured cellular immune responses.

Trust comment: Small randomized trial with direct human data but limited sample size and short follow-up; outcomes reported objectively.

Study Details

PMID:25661338
Participants:29
Impact:no in vivo change vs placebo after 60 days; in vitro zinc reduced IFN-γ in placebo-group PBMCs only
Trust score:3/5

anaemia prevalence (iron-only)

1 evidences

Large randomized trial in adolescents receiving iron, zinc, iron+zinc, or placebo for 24 weeks: iron (with or without zinc) reduced anaemia prevalence; zinc increased serum zinc but did not improve growth.

Trust comment: Large randomized controlled trial with adequate sample size and objective biomarkers though growth effects were not seen.

Study Details

PMID:17522609
Participants:821
Impact:reduced from 70.3% to 14.5% after supplementation
Trust score:4/5

anaemia prevalence (iron+zinc)

1 evidences

Large randomized trial in adolescents receiving iron, zinc, iron+zinc, or placebo for 24 weeks: iron (with or without zinc) reduced anaemia prevalence; zinc increased serum zinc but did not improve growth.

Trust comment: Large randomized controlled trial with adequate sample size and objective biomarkers though growth effects were not seen.

Study Details

PMID:17522609
Participants:821
Impact:reduced from 64.8% to 19.3% after supplementation
Trust score:4/5

serum zinc (zinc-only)

1 evidences

Large randomized trial in adolescents receiving iron, zinc, iron+zinc, or placebo for 24 weeks: iron (with or without zinc) reduced anaemia prevalence; zinc increased serum zinc but did not improve growth.

Trust comment: Large randomized controlled trial with adequate sample size and objective biomarkers though growth effects were not seen.

Study Details

PMID:17522609
Participants:821
Impact:mean change +4.3 μmol/L; combined group +4.0 μmol/L (no difference, p=0.82)
Trust score:4/5

low birth weight incidence

2 evidences

Randomized double-blind trial in pregnant women: micronutrient supplement raised maternal vitamin levels, was associated with 10% higher birth weights and fewer low-birth-weight infants; maternal plasma zinc correlated with newborn height.

Trust comment: Randomized double-blind placebo-controlled design but substantial attrition (100 recruited to 65 completed) limits certainty.

Study Details

PMID:14679367
Participants:65
Impact:decreased number of newborns <2700 g in supplemented group
Trust score:4/5

Large cluster RCT of antenatal micronutrient regimens found folic acid–iron reduced low birthweight; folic acid–iron–zinc showed no additional benefit over control for birth size.

Trust comment: Large, double-blind cluster RCT with thousands enrolled; zinc was given in combination so isolated zinc effects are not separable.

Study Details

PMID:12637400
Participants:4130
Impact:Folic acid–iron reduced % low birthweight from 43% to 34% (RR=0.84); multiple micronutrients reduced % low birthweight by 14% (RR~0.86)
Trust score:4/5

maternal plasma zinc correlation

1 evidences

Randomized double-blind trial in pregnant women: micronutrient supplement raised maternal vitamin levels, was associated with 10% higher birth weights and fewer low-birth-weight infants; maternal plasma zinc correlated with newborn height.

Trust comment: Randomized double-blind placebo-controlled design but substantial attrition (100 recruited to 65 completed) limits certainty.

Study Details

PMID:14679367
Participants:65
Impact:positive correlation with newborn height
Trust score:4/5

child zinc intake / nutrient density

1 evidences

A community feeding intervention increased mothers' knowledge and improved children's intakes of calcium, iron, niacin, and zinc, though calcium intake/density remained below desired levels.

Trust comment: Quasi-experimental community trial with sizable sample and practical outcomes but non-randomized design and residual nutrient gaps.

Study Details

PMID:25733629
Participants:455
Impact:increased but remained below target (CFR group 0.5 mg/100 kcal vs desired 0.6 mg/100 kcal)
Trust score:3/5

maternal knowledge and child feeding practices

1 evidences

A community feeding intervention increased mothers' knowledge and improved children's intakes of calcium, iron, niacin, and zinc, though calcium intake/density remained below desired levels.

Trust comment: Quasi-experimental community trial with sizable sample and practical outcomes but non-randomized design and residual nutrient gaps.

Study Details

PMID:25733629
Participants:455
Impact:improved with the CFR intervention
Trust score:3/5

Endothelial reactivity

1 evidences

Randomized double-blind placebo-controlled trial in 60 adults with moderate hypercholesterolemia; an 8-week nutraceutical containing bergamot/artichoke/Q10 and zinc improved lipids, inflammation markers and endothelial reactivity versus placebo.

Trust comment: Randomized, double-blind placebo-controlled trial with complete follow-up (n=60); modest sample size limits precision but design is strong.

Study Details

PMID:35631240
Participants:60
Impact:significant improvement vs baseline and vs placebo
Trust score:4/5

Gingival display

1 evidences

Parallel-group randomized trial (n=25) testing oral zinc given before BTXA injections for gummy smile; zinc prolonged and enhanced BTXA effect with higher patient satisfaction.

Trust comment: Randomized trial but small sample (n=25) with limited reporting details, so results are promising but imprecise.

Study Details

PMID:33950373
Participants:25
Impact:statistically significantly greater reduction and prolonged effect at 6–24 weeks vs BTXA alone
Trust score:3/5

patient satisfaction

1 evidences

Parallel-group randomized trial (n=25) testing oral zinc given before BTXA injections for gummy smile; zinc prolonged and enhanced BTXA effect with higher patient satisfaction.

Trust comment: Randomized trial but small sample (n=25) with limited reporting details, so results are promising but imprecise.

Study Details

PMID:33950373
Participants:25
Impact:increased/high satisfaction reported in zinc + BTXA group
Trust score:3/5

Mean serum zinc

1 evidences

Cross-sectional baseline survey of HIV-infected Ugandan children (1–5 y); measured serum zinc and associated factors.

Trust comment: Well-described cross-sectional analysis with clear laboratory methods and moderate sample size, but observational design limits causal inference.

Study Details

PMID:20858275
Participants:247
Impact:mean 10.0 μmol/L (SD 2.9)
Trust score:3/5

Association with HAART status

1 evidences

Cross-sectional baseline survey of HIV-infected Ugandan children (1–5 y); measured serum zinc and associated factors.

Trust comment: Well-described cross-sectional analysis with clear laboratory methods and moderate sample size, but observational design limits causal inference.

Study Details

PMID:20858275
Participants:247
Impact:lower prevalence of deficiency on HAART (29.5% on HAART vs 59.6% not on HAART)
Trust score:3/5

Respiratory distress / wheezing recovery

1 evidences

In infants hospitalized with bronchiolitis, one week of vitamin D (plus routine care) did not produce significant improvements in respiratory outcomes or hospital stay compared with control.

Trust comment: Randomized, blinded trial with adequate reporting; moderate sample but several dropouts and short-term intervention limit ability to detect effects.

Study Details

PMID:35692038
Participants:94
Impact:no significant improvement with zinc vs control at days 1, 3, 7
Trust score:3/5

Incidence of oral mucositis

1 evidences

Double-blind RCT in 90 children receiving intensified chemotherapy testing oral zinc 1 mg/kg/day for 14 days; zinc did not reduce incidence, severity or duration of oral mucositis versus placebo.

Trust comment: Randomized, double-blind placebo-controlled design with clear outcomes and adequate sample for the question; null result appears robust at the tested dose/duration.

Study Details

PMID:37057824
Participants:90
Impact:no difference (zinc 20.5% vs placebo 19.6%, p=0.91)
Trust score:4/5

Severity/duration of mucositis and hospitalizations

1 evidences

Double-blind RCT in 90 children receiving intensified chemotherapy testing oral zinc 1 mg/kg/day for 14 days; zinc did not reduce incidence, severity or duration of oral mucositis versus placebo.

Trust comment: Randomized, double-blind placebo-controlled design with clear outcomes and adequate sample for the question; null result appears robust at the tested dose/duration.

Study Details

PMID:37057824
Participants:90
Impact:no significant differences between groups
Trust score:4/5

Clinical malaria incidence

1 evidences

Community-based double-blind randomized trial in infants (6–24 months) comparing vitamin A + daily zinc vs vitamin A alone over 6 months; combined supplementation reduced clinical malaria incidence.

Trust comment: Cluster-randomized community trial with ~200 enrolled and 182 completing; randomized, well-conducted and shows a statistically significant malaria morbidity reduction.

Study Details

PMID:24330422
Participants:182
Impact:27% relative reduction (RR 0.73) in clinical malaria episodes in vitamin A + zinc vs vitamin A alone (p=0.03)
Trust score:4/5

Proportion reaching target zinc ≥80 μg/dL

1 evidences

Two multicenter studies: a double-blind RCT (NPC-02 zinc acetate, n≈56 efficacy-set) and a dose-adjustment study (n=43); zinc acetate significantly raised serum zinc and dose-dependently increased concentrations with acceptable safety.

Trust comment: Multicenter randomized placebo-controlled trial + dose-adjustment study with objective biochemical endpoints and transparent safety reporting; moderate sample but high internal validity.

Study Details

PMID:31392541
Participants:99
Impact:~50% in NPC-02 group vs 3.8% in placebo at week 8
Trust score:4/5

Dose–response / maintenance

1 evidences

Two multicenter studies: a double-blind RCT (NPC-02 zinc acetate, n≈56 efficacy-set) and a dose-adjustment study (n=43); zinc acetate significantly raised serum zinc and dose-dependently increased concentrations with acceptable safety.

Trust comment: Multicenter randomized placebo-controlled trial + dose-adjustment study with objective biochemical endpoints and transparent safety reporting; moderate sample but high internal validity.

Study Details

PMID:31392541
Participants:99
Impact:dose-dependent increases and 86% (37/43) maintained target concentration in dose-adjustment study
Trust score:4/5

Preference for novelty (FTII)

1 evidences

Zinc (alone or with iron/folic acid) did not consistently improve infant information-processing; the zinc+iron+folic acid group showed a small decrease in novelty preference at 52 weeks and mixed A-not-B task results.

Trust comment: Randomized sub-study with adequate sample but baseline imbalances and inconsistent/contradictory analyses reduce confidence.

Study Details

PMID:22283033
Participants:363
Impact:-2.06 points (62.06 vs 60.00) decrease with zinc+iron+folic acid vs placebo at 52 weeks (p<0.05)
Trust score:3/5

Fixation duration (FTII)

1 evidences

Zinc (alone or with iron/folic acid) did not consistently improve infant information-processing; the zinc+iron+folic acid group showed a small decrease in novelty preference at 52 weeks and mixed A-not-B task results.

Trust comment: Randomized sub-study with adequate sample but baseline imbalances and inconsistent/contradictory analyses reduce confidence.

Study Details

PMID:22283033
Participants:363
Impact:No significant change
Trust score:3/5

A-not-B error / Accurate performance

1 evidences

Zinc (alone or with iron/folic acid) did not consistently improve infant information-processing; the zinc+iron+folic acid group showed a small decrease in novelty preference at 52 weeks and mixed A-not-B task results.

Trust comment: Randomized sub-study with adequate sample but baseline imbalances and inconsistent/contradictory analyses reduce confidence.

Study Details

PMID:22283033
Participants:363
Impact:Mixed results across models; adjusted model showed reduced odds of A-not-B error at 52 weeks with zinc+iron+folic acid (OR=0.48, ~-52% odds, p<0.05)
Trust score:3/5

Gestational age / Preterm delivery

1 evidences

Adding 15 mg/day zinc from 16 weeks gestation to routine iron/folic acid did not improve birth weight or other measured pregnancy outcomes.

Trust comment: Large randomized controlled trial with clear null findings and adequate sample size.

Study Details

PMID:26365330
Participants:540
Impact:No significant difference (preterm incidence p=0.999)
Trust score:4/5

Low birth weight / Apgar

1 evidences

Adding 15 mg/day zinc from 16 weeks gestation to routine iron/folic acid did not improve birth weight or other measured pregnancy outcomes.

Trust comment: Large randomized controlled trial with clear null findings and adequate sample size.

Study Details

PMID:26365330
Participants:540
Impact:No significant difference in incidence of low birth weight or 5-min Apgar >7
Trust score:4/5

Serum zinc change (3 months)

1 evidences

In hemodialysis patients receiving zinc supplements, higher pre-dialysis serum creatinine was associated with poorer/late biochemical response to zinc over 3 months.

Trust comment: Retrospective analysis of a prior randomized cohort with modest sample size; associations plausible but observational and secondary.

Study Details

PMID:32557260
Participants:86
Impact:Negative correlation with pre-dialysis serum creatinine (r = -0.284, p = 0.008)
Trust score:3/5

Late response to zinc supplementation

1 evidences

In hemodialysis patients receiving zinc supplements, higher pre-dialysis serum creatinine was associated with poorer/late biochemical response to zinc over 3 months.

Trust comment: Retrospective analysis of a prior randomized cohort with modest sample size; associations plausible but observational and secondary.

Study Details

PMID:32557260
Participants:86
Impact:Pre-dialysis SCre ≥10.0 mg/dL associated with higher odds of late response (OR=3.71, 95% CI 1.24–11.1, p=0.022)
Trust score:3/5

COPD exacerbation severity and duration

1 evidences

A combination tablet containing Echinacea plus zinc, selenium and vitamin C (EP+) reduced severity and duration of COPD exacerbations after URTI compared with placebo; effect attributed to the combination, not zinc alone.

Trust comment: Randomized controlled design but the tested product was a multi-nutrient combination, so zinc-specific effects are not isolated.

Study Details

PMID:21062330
Participants:108
Impact:Significantly reduced with EP+ (combination including zinc) versus placebo (no numeric effect size reported)
Trust score:3/5

fecal sIgA (humoral immune response)

1 evidences

90-day randomized, double-blind trial in 12–24 month olds testing probiotic, zinc (8 mg elemental), their combination, or placebo.

Trust comment: Double-blind RCT but small sample (n=48) limits precision and generalizability.

Study Details

PMID:25183688
Participants:48
Impact:increased — probiotic: 30.33±3.32 μg/g vs placebo 13.58±2.26 μg/g; combo: 27.55±2.28 μg/g
Trust score:3/5

serum/plasma zinc concentration

1 evidences

90-day randomized, double-blind trial in 12–24 month olds testing probiotic, zinc (8 mg elemental), their combination, or placebo.

Trust comment: Double-blind RCT but small sample (n=48) limits precision and generalizability.

Study Details

PMID:25183688
Participants:48
Impact:highest elevation observed in probiotic + zinc combination group
Trust score:3/5

plasma zinc concentration (PZC)

4 evidences

Providing biofortified wheat increased dietary zinc by ~1.5 mg/day but did not raise plasma zinc; it was associated with a reduction in an inflammation marker (AGP).

Trust comment: Large double-blind cluster RCT with good sample size, high compliance, and appropriate analyses; results robust.

Study Details

PMID:35458222
Participants:407
Impact:no significant change (endline β=8.6 µg/L; p=0.46)
Trust score:5/5

Randomized trial in healthy adult men (25 mg zinc daily for 13 days) comparing zinc taken fasted vs with food; measured plasma zinc and estimated FADS activities.

Trust comment: Small, short-duration randomized trial (n=35); randomized design but limited sample size and brief intervention reduce generalizability.

Study Details

PMID:34236435
Participants:35
Impact:higher when zinc taken fasted: ZBB 105 vs ZWB 88.7 μg/dL (~+18% in ZBB vs ZWB)
Trust score:3/5

Cluster-randomized trial (biochemistry subgroup) in infants found varying zinc doses in SQ-LNS did not change plasma zinc, while the SQ-LNS plus illness treatment improved iron and vitamin A status and reduced anemia prevalence compared with non-intervention cohort.

Trust comment: Large cluster-randomized trial with biochemical outcomes and appropriate adjustments, though zinc adherence/absorption issues limit interpretation of zinc-specific effects.

Study Details

PMID:28152989
Participants:404
Impact:No significant change by zinc dose or form (no effect of supplementation on pZC)
Trust score:4/5

9-month double-masked RCT in 1–3 y old stunted, mostly zinc-deficient children comparing zinc-biofortified rice vs control rice; primary outcome plasma zinc concentration.

Trust comment: Large, well-conducted double-masked randomized trial (n=520) with robust methods and endpoints; primary outcome showed no effect.

Study Details

PMID:34792094
Participants:520
Impact:no benefit of biofortified rice; PZC declined in both groups (CR: 60.8→55.1 μg/dL, −5.7; BFR: 59.9→55.6 μg/dL, −4.3)
Trust score:5/5

prevalence of zinc deficiency (PZC <65 μg/dL)

1 evidences

9-month double-masked RCT in 1–3 y old stunted, mostly zinc-deficient children comparing zinc-biofortified rice vs control rice; primary outcome plasma zinc concentration.

Trust comment: Large, well-conducted double-masked randomized trial (n=520) with robust methods and endpoints; primary outcome showed no effect.

Study Details

PMID:34792094
Participants:520
Impact:increased over study — CR +8.7% (75.9→84.6%); BFR +3.7% (80.3→84.0%)
Trust score:5/5

infection-related morbidity (total and respiratory)

1 evidences

9-month double-masked RCT in 1–3 y old stunted, mostly zinc-deficient children comparing zinc-biofortified rice vs control rice; primary outcome plasma zinc concentration.

Trust comment: Large, well-conducted double-masked randomized trial (n=520) with robust methods and endpoints; primary outcome showed no effect.

Study Details

PMID:34792094
Participants:520
Impact:higher in BFR vs CR (total morbidity LPR 1.08, 95% CI 1.05–1.12; cold LPR 1.09; chest problems LPR 1.26)
Trust score:5/5

FADS1 activity index (EFA desaturation)

1 evidences

Randomized trial in healthy adult men (25 mg zinc daily for 13 days) comparing zinc taken fasted vs with food; measured plasma zinc and estimated FADS activities.

Trust comment: Small, short-duration randomized trial (n=35); randomized design but limited sample size and brief intervention reduce generalizability.

Study Details

PMID:34236435
Participants:35
Impact:higher when zinc taken with food: ZWB geometric mean 6.45 vs ZBB 5.57 (~+15% in ZWB)
Trust score:3/5

fetal heart rate variability

1 evidences

Randomized prenatal supplement trial (iron+folate with or without 15 mg zinc) in pregnant women; fetal heart rate and movement were assessed at 32 and 36 weeks.

Trust comment: Small randomized study (n=55) with objective fetal measures; limited sample size but randomized design supports credibility.

Study Details

PMID:9988823
Participants:55
Impact:fewer episodes of minimal variability in fetuses of zinc-supplemented mothers (significant at 36 weeks)
Trust score:3/5

fetal heart rate range and accelerations

1 evidences

Randomized prenatal supplement trial (iron+folate with or without 15 mg zinc) in pregnant women; fetal heart rate and movement were assessed at 32 and 36 weeks.

Trust comment: Small randomized study (n=55) with objective fetal measures; limited sample size but randomized design supports credibility.

Study Details

PMID:9988823
Participants:55
Impact:increased at 36 weeks in zinc group (statistically significant)
Trust score:3/5

fetal movements (movement bouts, time moving, large movements)

1 evidences

Randomized prenatal supplement trial (iron+folate with or without 15 mg zinc) in pregnant women; fetal heart rate and movement were assessed at 32 and 36 weeks.

Trust comment: Small randomized study (n=55) with objective fetal measures; limited sample size but randomized design supports credibility.

Study Details

PMID:9988823
Participants:55
Impact:increased in fetuses of zinc-supplemented mothers (significant at 36 weeks)
Trust score:3/5

fat free mass (FFM) / body weight

1 evidences

Randomized controlled trial in hospitalized adults with HIV comparing standard diet vs standard + 100 g RUTF (provided zinc among other nutrients); final analysis n=37.

Trust comment: Randomized trial but with modest final sample (n=37), notable attrition and hospital deaths; results for body composition and anemia are plausible but zinc outcome null.

Study Details

PMID:26728978
Participants:37
Impact:FFM +11.8% and body weight +11% in supplemented group over 3 months (FFM p=0.033; weight p=0.033)
Trust score:3/5

plasma zinc concentration (zinc status)

1 evidences

Randomized controlled trial in hospitalized adults with HIV comparing standard diet vs standard + 100 g RUTF (provided zinc among other nutrients); final analysis n=37.

Trust comment: Randomized trial but with modest final sample (n=37), notable attrition and hospital deaths; results for body composition and anemia are plausible but zinc outcome null.

Study Details

PMID:26728978
Participants:37
Impact:no significant change in plasma zinc between RUTF and control groups (p=0.811)
Trust score:3/5

migraine attacks frequency

1 evidences

In migraine patients, 8 weeks of zinc (50 mg elemental) reduced monthly attack frequency; other migraine measures changed less consistently.

Trust comment: Randomized double-blind trial with complete follow-up (n=80) and adjusted analyses, but modest sample size and some outcomes lost significance after adjustment.

Study Details

PMID:32928216
Participants:80
Impact:-2.59 attacks/month (adjusted change vs placebo)
Trust score:4/5

Headache severity (VAS)

1 evidences

In migraine patients, 8 weeks of zinc (50 mg elemental) reduced monthly attack frequency; other migraine measures changed less consistently.

Trust comment: Randomized double-blind trial with complete follow-up (n=80) and adjusted analyses, but modest sample size and some outcomes lost significance after adjustment.

Study Details

PMID:32928216
Participants:80
Impact:-1.45 VAS points (adjusted change vs placebo; not statistically significant in adjusted model)
Trust score:4/5

head circumference z score

1 evidences

In Nepali infants, zinc supplementation modestly reduced the rate of decline in head circumference z-score over one year.

Trust comment: Large randomized controlled trial (n=569) with repeated measures and appropriate adjustments, showing a small but statistically significant effect on head growth.

Study Details

PMID:22569086
Participants:569
Impact:+0.13 z-score (visit1→visit5, adjusted difference vs placebo)
Trust score:4/5

treatment cost

1 evidences

In children with acute diarrhea, adding zinc (or zinc+copper) increased treatment costs without providing additional clinical benefit in this study.

Trust comment: Large randomized trial with economic analysis (n=808); strong on cost data but reported no added clinical benefit—methodologically sound but context-specific cost conclusions.

Study Details

PMID:23177894
Participants:808
Impact:1.5× higher cost (zinc vs placebo); 1.7× higher cost (Zn+Cu vs placebo)
Trust score:3/5

clinical benefit for diarrhea outcomes

1 evidences

In children with acute diarrhea, adding zinc (or zinc+copper) increased treatment costs without providing additional clinical benefit in this study.

Trust comment: Large randomized trial with economic analysis (n=808); strong on cost data but reported no added clinical benefit—methodologically sound but context-specific cost conclusions.

Study Details

PMID:23177894
Participants:808
Impact:no additional beneficial clinical effect observed with zinc or zinc+cu
Trust score:3/5

growth (weight/height z-scores)

1 evidences

Daily sprinkles containing multiple micronutrients (including 5 mg zinc) improved anemia recovery versus placebo but did not prevent declines in growth z-scores.

Trust comment: Randomized controlled trial (n=204) but zinc was provided as part of a multi-micronutrient mix, limiting attribution of effects specifically to zinc.

Study Details

PMID:16540800
Participants:204
Impact:no benefit on growth; weight-for-age and height-for-age z-scores declined similarly across groups
Trust score:3/5

Gingival inflammation (Gingival Index)

2 evidences

A regimen including zinc-containing toothpaste and zinc-containing mouthwash produced greater reductions in gingival inflammation and plaque than control over 1–6 months.

Trust comment: Randomized clinical trial (n=94) with blinded examiner and consistent clinical endpoints; effects were clear early but differences diminished after regimen convergence.

Study Details

PMID:37794683
Participants:94
Impact:greater reduction vs control at 1, 3, and 6 months (statistically significant)
Trust score:4/5

Adding a dentifrice and rinse containing sanguinaria extract and zinc chloride to initial periodontal therapy provided no additional short-term benefit over placebo.

Trust comment: Randomized double-blind trial but small sample size limits power to detect small effects; zinc present as part of product rather than isolated intervention.

Study Details

PMID:9078647
Participants:34
Impact:no difference between groups
Trust score:3/5

supragingival plaque (plaque index)

1 evidences

A regimen including zinc-containing toothpaste and zinc-containing mouthwash produced greater reductions in gingival inflammation and plaque than control over 1–6 months.

Trust comment: Randomized clinical trial (n=94) with blinded examiner and consistent clinical endpoints; effects were clear early but differences diminished after regimen convergence.

Study Details

PMID:37794683
Participants:94
Impact:greater reduction vs control at 1, 3, and 6 months (statistically significant)
Trust score:4/5

serum fructosamine

1 evidences

Short course (10 days) of sugar-free zinc lozenges did not change serum fructosamine or glucose measures in people with diabetes.

Trust comment: Small randomized study (n=48) adequately measured glycemic markers for short-term safety, but limited by short duration and small sample.

Study Details

PMID:11441324
Participants:48
Impact:-9 ± 90 μmol/L (zinc) vs -7 ± 42 μmol/L (placebo) after 10 days; no significant difference
Trust score:3/5

home/fasting glucose

1 evidences

Short course (10 days) of sugar-free zinc lozenges did not change serum fructosamine or glucose measures in people with diabetes.

Trust comment: Small randomized study (n=48) adequately measured glycemic markers for short-term safety, but limited by short duration and small sample.

Study Details

PMID:11441324
Participants:48
Impact:no significant change vs placebo at days 10 and 21
Trust score:3/5

Fat-free mass (FFM)

1 evidences

Giving small-quantity lipid-based nutrient supplements (with morbidity treatment) to 9–18 month old children increased weight and lean mass; adding extra zinc (in LNS or tablets) had no detectable effect on body composition.

Trust comment: Well-conducted cluster-randomized trial with objective deuterium dilution body-composition measures but limited sub-study size and adherence concerns may limit zinc-specific inferences.

Study Details

PMID:35829783
Participants:275
Impact:Intervention cohort FFM change +1.57 kg vs +1.35 kg in non-intervention cohort; no effect of zinc dose.
Trust score:4/5

fat mass (% body weight)

1 evidences

Giving small-quantity lipid-based nutrient supplements (with morbidity treatment) to 9–18 month old children increased weight and lean mass; adding extra zinc (in LNS or tablets) had no detectable effect on body composition.

Trust comment: Well-conducted cluster-randomized trial with objective deuterium dilution body-composition measures but limited sub-study size and adherence concerns may limit zinc-specific inferences.

Study Details

PMID:35829783
Participants:275
Impact:No significant difference in %FM accrual (IC −1.3% vs NIC −1.0%); no effect of zinc dose.
Trust score:4/5

cognitive performance

2 evidences

Six months of daily zinc (and/or iron) in lead-exposed children did not produce consistent or lasting improvements in cognitive test performance.

Trust comment: Large randomized, double-blind, placebo-controlled field trial with good follow-up and multiple cognitive endpoints.

Study Details

PMID:16510631
Participants:527
Impact:no consistent or lasting improvement with iron and/or zinc supplementation
Trust score:5/5

Long-term supplementation with antioxidants and zinc+copper had no detectable benefit or harm on cognition in older adults.

Trust comment: Large randomized controlled trial with long follow-up and validated cognitive testing showing consistent null findings.

Study Details

PMID:15534261
Participants:2166
Impact:No significant difference across treatment groups on any of six cognitive tests after median 6.9 years of treatment.
Trust score:5/5

motor milestone scores

1 evidences

Daily zinc (alone or with iron-folic acid) for one year did not improve motor or language milestone attainment in Nepali infants and toddlers.

Trust comment: Randomized trial with repeated measures and adjustment for confounders; moderate sample size and clear null results for milestones.

Study Details

PMID:23298972
Participants:544
Impact:No significant effect of zinc (adjusted β ≈ −0.7, 95% CI −1.4 to 0.01 for cumulative change; adjusted rate changes non-significant).
Trust score:4/5

language milestone scores

1 evidences

Daily zinc (alone or with iron-folic acid) for one year did not improve motor or language milestone attainment in Nepali infants and toddlers.

Trust comment: Randomized trial with repeated measures and adjustment for confounders; moderate sample size and clear null results for milestones.

Study Details

PMID:23298972
Participants:544
Impact:Crude lower change with zinc lost significance after adjustment (adjusted β ≈ −0.2, 95% CI −0.6 to 0.2); no beneficial effect.
Trust score:4/5

haemoglobin / anaemia

1 evidences

A 3-year homestead food production programme did not change haemoglobin, iron, vitamin A, or zinc biomarker status in women or children at endline.

Trust comment: Large, well-designed cluster-randomized trial with biomarker measurements and appropriate adjustments; null effects for zinc outcomes.

Study Details

PMID:40387380
Participants:3413
Impact:No intervention effect on haemoglobin (nonpregnant women adjusted β ≈ −0.06 g/dL, p=0.17) or anaemia prevalence.
Trust score:5/5

inflammation biomarkers (CRP, AGP)

1 evidences

A 3-year homestead food production programme did not change haemoglobin, iron, vitamin A, or zinc biomarker status in women or children at endline.

Trust comment: Large, well-designed cluster-randomized trial with biomarker measurements and appropriate adjustments; null effects for zinc outcomes.

Study Details

PMID:40387380
Participants:3413
Impact:No intervention impact on CRP or AGP; inflammation prevalence unchanged.
Trust score:5/5

anaemia prevalence

1 evidences

In a cluster randomized trial of young children, iron-containing micronutrient powder (which also contained 5 mg zinc) modestly improved haemoglobin and reduced anaemia and iron deficiency compared to non-iron MNP.

Trust comment: Large double-blind cluster randomized trial with intention-to-treat analysis and appropriate biomarker assessment; high confidence.

Study Details

PMID:33571267
Participants:1806
Impact:-8.29% (difference-in-difference; lower in iron group)
Trust score:5/5

hs-CRP (inflammation)

1 evidences

In 60 women with PCOS, 12 weeks of magnesium plus zinc supplementation reduced inflammatory and oxidative stress biomarkers and downregulated inflammatory gene expression compared with placebo.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear biomarker outcomes though modest sample size.

Study Details

PMID:29127547
Participants:60
Impact:-1.6 mg/L (magnesium+zinc) vs +0.1 mg/L (placebo); between-group P=0.001
Trust score:4/5

Protein carbonyl (oxidative stress)

1 evidences

In 60 women with PCOS, 12 weeks of magnesium plus zinc supplementation reduced inflammatory and oxidative stress biomarkers and downregulated inflammatory gene expression compared with placebo.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear biomarker outcomes though modest sample size.

Study Details

PMID:29127547
Participants:60
Impact:-0.14 mmol/mg protein (magnesium+zinc) vs +0.02 mmol/mg protein (placebo); P=0.002
Trust score:4/5

total antioxidant capacity (TAC)

6 evidences

Twelve weeks of magnesium-zinc-calcium-vitamin D co-supplementation in women with PCOS reduced hirsutism and some inflammation/oxidative stress markers and increased antioxidant capacity.

Trust comment: Randomized double-blind placebo-controlled trial with clear biomarker changes, but co-supplementation prevents attribution of effects solely to zinc.

Study Details

PMID:28668998
Participants:60
Impact:+46.6 ± 66.5 mmol/L vs -7.7 ± 130.1 mmol/L (change)
Trust score:4/5

In 60 women with PCOS, 12 weeks of magnesium plus zinc supplementation reduced inflammatory and oxidative stress biomarkers and downregulated inflammatory gene expression compared with placebo.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear biomarker outcomes though modest sample size.

Study Details

PMID:29127547
Participants:60
Impact:+60.7 mmol/L (magnesium+zinc) vs -1.5 mmol/L (placebo); P=0.03
Trust score:4/5

In women with gestational diabetes, 6 weeks of zinc (30 mg/day) increased serum zinc and antioxidant capacity and lowered hs-CRP, without changing pregnancy outcomes.

Trust comment: Randomized, double-blind, placebo-controlled trial but small sample (n=50) limits precision.

Study Details

PMID:26465829
Participants:50
Impact:increase (+60.0 mmol/L vs −28.4 mmol/L in placebo; P=0.006)
Trust score:4/5

In women with T2DM and CHD, 12-week combined magnesium and zinc supplementation modestly improved fasting glucose, insulin, HDL, inflammatory marker CRP, antioxidant markers, and depression/anxiety scores versus placebo.

Trust comment: Randomized, double-blind, placebo-controlled trial with objective biochemical endpoints but modest sample size.

Study Details

PMID:32466773
Participants:55
Impact:Between-group β +43.44 mmol/L (95% CI 3.39, 83.50); P=0.03
Trust score:4/5

In pregnant women at risk for IUGR, 30 mg/day zinc for 10 weeks reduced inflammation and oxidative stress markers and lowered insulin; no effect on uterine artery PI.

Trust comment: Randomized double-blind placebo-controlled trial with biomarker endpoints but small sample (n=52) limits generalizability.

Study Details

PMID:31248307
Participants:52
Impact:+59.22 mmol/L (β)
Trust score:4/5

Eight weeks of zinc supplementation in postmenopausal women improved erythrocyte zinc status and was associated with enhanced antioxidant markers.

Trust comment: Double-blind randomized design supports causality but sample size is small and outcomes are biomarker/correlational.

Study Details

PMID:35278643
Participants:51
Impact:positively correlated with erythrocyte Zn after intervention (r = 0.96; p < 0.001)
Trust score:4/5

IL-1 and TNF-α gene expression

1 evidences

In 60 women with PCOS, 12 weeks of magnesium plus zinc supplementation reduced inflammatory and oxidative stress biomarkers and downregulated inflammatory gene expression compared with placebo.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear biomarker outcomes though modest sample size.

Study Details

PMID:29127547
Participants:60
Impact:Downregulated in PBMCs vs placebo (IL-1 P=0.007, TNF-α P=0.03)
Trust score:4/5

Nasal symptom scores (itching, sneezing, total)

1 evidences

In 40 patients with seasonal allergic rhinitis, adding oral quail egg with zinc to topical steroid therapy improved nasal symptoms and control compared with steroid alone.

Trust comment: Randomised trial but small sample (n=40) and limited reporting—results are preliminary.

Study Details

PMID:35582999
Participants:40
Impact:Greater reduction with mometasone + quail egg/zinc vs mometasone alone (no numeric effect sizes reported)
Trust score:3/5

Rhinitis control (need for rescue medication)

1 evidences

In 40 patients with seasonal allergic rhinitis, adding oral quail egg with zinc to topical steroid therapy improved nasal symptoms and control compared with steroid alone.

Trust comment: Randomised trial but small sample (n=40) and limited reporting—results are preliminary.

Study Details

PMID:35582999
Participants:40
Impact:Higher proportion with good control and no rescue medication in the quail egg/zinc adjunct group
Trust score:3/5

UFMI diagnostic performance (Zn-coproporphyrin detection)

1 evidences

Study of a urine fluorometry index (UFMI) that identifies Zn-coproporphyrin to diagnose neonatal meconium aspiration syndrome (MAS) with high accuracy.

Trust comment: Human neonatal diagnostic study showing strong accuracy metrics but older single-study data and limited detail on validation.

Study Details

PMID:8745496
Participants:68
Impact:Sensitivity 100%, Specificity 97% for MAS (UFMI)
Trust score:3/5

Fasting plasma glucose (FPG)

4 evidences

In adults with prediabetes, 20 mg/day zinc reduced progression to type 2 diabetes and improved glycemic and some lipid measures over 12 months.

Trust comment: Randomized, double-blind, placebo-controlled trial (n=200) with clear endpoints and statistically significant results.

Study Details

PMID:29072815
Participants:200
Impact:decreased (significant)
Trust score:5/5

6-month RCT of Lysulin (lysine, zinc, vitamin C) in pre-diabetes reduced progression to diabetes and improved glycaemic and lipid measures versus placebo.

Trust comment: Well-designed RCT with clinically meaningful endpoints, but formulation contains multiple active ingredients so effects cannot be attributed solely to zinc.

Study Details

PMID:32795739
Participants:110
Impact:significant reduction in Lysulin group (value not reported)
Trust score:3/5

In 60 women with gestational diabetes, 6 weeks of magnesium-zinc-calcium-vitamin D reduced inflammation and oxidative stress markers and modestly lowered fasting glucose.

Trust comment: Double-blind, placebo-controlled randomized trial with clear biomarker outcomes though multi-nutrient co-supplementation limits attribution to zinc alone.

Study Details

PMID:30922259
Participants:60
Impact:−4.3 ± 4.9 mg/dL vs −0.9 ± 4.5 in placebo (P = 0.008)
Trust score:4/5

In women with T2DM and CHD, 12-week combined magnesium and zinc supplementation modestly improved fasting glucose, insulin, HDL, inflammatory marker CRP, antioxidant markers, and depression/anxiety scores versus placebo.

Trust comment: Randomized, double-blind, placebo-controlled trial with objective biochemical endpoints but modest sample size.

Study Details

PMID:32466773
Participants:55
Impact:Between-group β −9.44 mg/dL (95% CI −18.30, −0.57); P=0.03
Trust score:4/5

Yale-Brown Obsessive-Compulsive Scale score

1 evidences

Adding zinc to fluoxetine improved OCD scale scores more than fluoxetine alone over 8 weeks.

Trust comment: Small, double-blind randomized trial (n=23) with clear outcome but limited sample size.

Study Details

PMID:22465904
Participants:23
Impact:decrease (fluoxetine + zinc significantly lower than fluoxetine + placebo at weeks 2 and 8)
Trust score:3/5

mucositis severity/onset

1 evidences

Oral zinc given during radiotherapy delayed and reduced severity of mucositis and dermatitis versus placebo.

Trust comment: Double-blind randomized trial with 100 patients and clear clinical endpoints; results appear robust though subgroup effects (chemotherapy) were limited.

Study Details

PMID:16751063
Participants:100
Impact:delayed onset and reduced severity (fewer and later Grade 2–3 mucositis cases in zinc group)
Trust score:4/5

dermatitis severity/onset

1 evidences

Oral zinc given during radiotherapy delayed and reduced severity of mucositis and dermatitis versus placebo.

Trust comment: Double-blind randomized trial with 100 patients and clear clinical endpoints; results appear robust though subgroup effects (chemotherapy) were limited.

Study Details

PMID:16751063
Participants:100
Impact:delayed onset and reduced severity (fewer and later Grade 2–3 dermatitis cases in zinc group)
Trust score:4/5

serum iron concentration

1 evidences

Daily 10 mg zinc for 3 months raised serum zinc and reduced serum iron (AUC) in healthy 8–9-year-old children without causing anemia.

Trust comment: Randomized, triple-blind trial with full follow-up (n=30); well-controlled biochemical measures though sample size is small.

Study Details

PMID:25192026
Participants:30
Impact:decrease (basal serum iron and area under the iron curve decreased after 3 months of zinc)
Trust score:4/5

iron deficiency at 6 months

1 evidences

In infants, zinc increased risk of iron deficiency at 6 months while multivitamins reduced iron deficiency and lowered risk of severe anemia; zinc did not increase long-term anemia risk.

Trust comment: Large, double-blind randomized 2×2 factorial RCT (n>2000) with appropriate hematologic endpoints and rigorous analyses.

Study Details

PMID:28876332
Participants:2006
Impact:increased with zinc (OR 1.8; p<0.05)
Trust score:5/5

severe anemia risk

1 evidences

In infants, zinc increased risk of iron deficiency at 6 months while multivitamins reduced iron deficiency and lowered risk of severe anemia; zinc did not increase long-term anemia risk.

Trust comment: Large, double-blind randomized 2×2 factorial RCT (n>2000) with appropriate hematologic endpoints and rigorous analyses.

Study Details

PMID:28876332
Participants:2006
Impact:reduced with multivitamin (HR 0.72, 28% reduction)
Trust score:5/5

new antibiotic prescriptions

1 evidences

Among nursing-home residents, normal serum zinc was associated with lower pneumonia incidence, shorter illness duration, fewer antibiotic prescriptions, and lower mortality.

Trust comment: Observational analysis (n=578 baseline measures) nested within a trial; associations are plausible but not randomized for zinc status.

Study Details

PMID:17921398
Participants:578
Impact:decrease (about 50% fewer new antibiotic prescriptions with normal final serum zinc)
Trust score:3/5

duration of pneumonia / days of antibiotic use

1 evidences

Among nursing-home residents, normal serum zinc was associated with lower pneumonia incidence, shorter illness duration, fewer antibiotic prescriptions, and lower mortality.

Trust comment: Observational analysis (n=578 baseline measures) nested within a trial; associations are plausible but not randomized for zinc status.

Study Details

PMID:17921398
Participants:578
Impact:decrease (shorter pneumonia duration and fewer antibiotic days: 3.9 d vs 2.6 d)
Trust score:3/5

plasma selenium

1 evidences

Giving one egg daily for six months did not improve plasma zinc, selenium, copper or magnesium; plasma iron decreased in the egg group.

Trust comment: Large randomized controlled trial with blinded outcome assessment and measured biomarkers; secondary analysis with some sample loss but appropriate adjustments.

Study Details

PMID:37095119
Participants:387
Impact:Mean difference −0.35 µg/L (95% CI −4.48 to 3.79); no significant change
Trust score:4/5

offspring insulin resistance (HOMA-IR)

1 evidences

Maternal B12 deficiency in pregnancy was linked to higher insulin resistance in school-aged offspring; antenatal micronutrient supplements (including groups that contained zinc) did not significantly alter this outcome.

Trust comment: Large cluster-randomized trial with biomarker sub-sample and long follow-up; supplementation arms included zinc but zinc effect not isolated.

Study Details

PMID:21865563
Participants:1132
Impact:Maternal vitamin B12 deficiency associated with +26.7% HOMA-IR in offspring (P=0.02)
Trust score:4/5

Effect of antenatal folic acid+iron+zinc on offspring HOMA-IR

1 evidences

Maternal B12 deficiency in pregnancy was linked to higher insulin resistance in school-aged offspring; antenatal micronutrient supplements (including groups that contained zinc) did not significantly alter this outcome.

Trust comment: Large cluster-randomized trial with biomarker sub-sample and long follow-up; supplementation arms included zinc but zinc effect not isolated.

Study Details

PMID:21865563
Participants:1132
Impact:Among B12-deficient mothers, folic acid+iron+zinc group change +3.3% (95% CI −38.4 to 73.5); not significant
Trust score:4/5

Overall effect of antenatal micronutrient supplementation (including zinc-containing arms)

1 evidences

Maternal B12 deficiency in pregnancy was linked to higher insulin resistance in school-aged offspring; antenatal micronutrient supplements (including groups that contained zinc) did not significantly alter this outcome.

Trust comment: Large cluster-randomized trial with biomarker sub-sample and long follow-up; supplementation arms included zinc but zinc effect not isolated.

Study Details

PMID:21865563
Participants:1132
Impact:No significant impact of supplementation groups on offspring HOMA-IR in this analysis
Trust score:4/5

Fractional zinc absorption (rice-based)

1 evidences

Adding casein phosphopeptides to rice-based infant cereal increased zinc (and calcium) absorption; no effect when added to whole-grain cereal.

Trust comment: Small single-meal controlled study with isotope-based absorption measures—physiologic but limited sample size and acute-meal setting.

Study Details

PMID:9093988
Participants:22
Impact:Increased from 19.4% to 25.2% (1 g CPP) and 23.9% (2 g CPP); p=0.04
Trust score:3/5

Total zinc absorbed (rice-based)

1 evidences

Adding casein phosphopeptides to rice-based infant cereal increased zinc (and calcium) absorption; no effect when added to whole-grain cereal.

Trust comment: Small single-meal controlled study with isotope-based absorption measures—physiologic but limited sample size and acute-meal setting.

Study Details

PMID:9093988
Participants:22
Impact:Increased from 0.25 mg to 0.33 mg (1 g CPP) and 0.31 mg (2 g CPP)
Trust score:3/5

Zinc absorption (whole-grain)

1 evidences

Adding casein phosphopeptides to rice-based infant cereal increased zinc (and calcium) absorption; no effect when added to whole-grain cereal.

Trust comment: Small single-meal controlled study with isotope-based absorption measures—physiologic but limited sample size and acute-meal setting.

Study Details

PMID:9093988
Participants:22
Impact:No change in fractional or total zinc absorption with CPP addition
Trust score:3/5

Onset of severe mucositis (oral cancer)

1 evidences

Zinc supplementation during radiotherapy delayed development of severe mucositis in patients with oral cancers but showed no benefit in nasopharyngeal carcinoma patients.

Trust comment: Double-blind randomized trial but subgroup analyses with modest subgroup sizes and potential confounding (pre-treatment mucosa, habits) limit strength.

Study Details

PMID:20574929
Participants:100
Impact:Zinc supplementation postponed development of Grade 2/3 mucositis in oral cancer subgroup (benefit vs placebo)
Trust score:3/5

Effect in nasopharyngeal carcinoma

1 evidences

Zinc supplementation during radiotherapy delayed development of severe mucositis in patients with oral cancers but showed no benefit in nasopharyngeal carcinoma patients.

Trust comment: Double-blind randomized trial but subgroup analyses with modest subgroup sizes and potential confounding (pre-treatment mucosa, habits) limit strength.

Study Details

PMID:20574929
Participants:100
Impact:No benefit of zinc supplementation on mucositis in NPC subgroup
Trust score:3/5

Erythropoietin responsiveness index (ERI)

1 evidences

Daily oral polaprezinc (34 mg Zn/day) in zinc-deficient hemodialysis patients increased serum zinc, lowered serum copper and ferritin, and reduced the erythropoietin responsiveness index (ERI), allowing lower ESA requirements.

Trust comment: Randomized multicenter trial in zinc-deficient HD patients with objective biochemical and clinical endpoints; open-label and modest size are limitations.

Study Details

PMID:25988769
Participants:66
Impact:Significant reduction in ERI in polaprezinc group vs control (difference significant from months 10–12)
Trust score:4/5

Serum IGF-I response

1 evidences

Adding 30 mg/day zinc to essential amino acids-whey protein supplements in frail elderly accelerated IGF-I rise, reduced a bone resorption marker, and improved activities of daily living over 4 weeks.

Trust comment: Randomized, double-blind supplement trial in hospitalized frail elderly with objective biomarkers, moderate sample size and short duration.

Study Details

PMID:19536417
Participants:61
Impact:At 1 week, zinc group +48.2% vs control +22.4% (p<0.05)
Trust score:4/5

bone resorption marker (CrossLaps)

1 evidences

Adding 30 mg/day zinc to essential amino acids-whey protein supplements in frail elderly accelerated IGF-I rise, reduced a bone resorption marker, and improved activities of daily living over 4 weeks.

Trust comment: Randomized, double-blind supplement trial in hospitalized frail elderly with objective biomarkers, moderate sample size and short duration.

Study Details

PMID:19536417
Participants:61
Impact:CrossLaps decreased significantly in zinc group by 1 week
Trust score:4/5

activities of daily living

1 evidences

Adding 30 mg/day zinc to essential amino acids-whey protein supplements in frail elderly accelerated IGF-I rise, reduced a bone resorption marker, and improved activities of daily living over 4 weeks.

Trust comment: Randomized, double-blind supplement trial in hospitalized frail elderly with objective biomarkers, moderate sample size and short duration.

Study Details

PMID:19536417
Participants:61
Impact:Improved +27.0% (zinc) vs +18.3% (control) over 4 weeks
Trust score:4/5

P1NP (bone formation marker)

1 evidences

Four weeks of daily zinc (9 mg) in 9–11 y girls raised blood zinc and a bone formation marker.

Trust comment: Randomized controlled trial with objective biomarker outcomes in 147 participants; short (4-week) duration limits long-term conclusions.

Study Details

PMID:26491117
Participants:147
Impact:↑ mean change 23.8 μmol/L (zinc) vs −31.0 μmol/L (placebo); P=0.04
Trust score:4/5

insulin

1 evidences

Eight weeks of daily zinc (20 mg) in obese prepubertal children reduced fasting glucose, insulin and insulin resistance.

Trust comment: Triple-masked randomized placebo-controlled crossover trial with objective metabolic measures but modest sample size.

Study Details

PMID:20045801
Participants:60
Impact:↓ (significant) after zinc
Trust score:4/5

duration of illness / time to recovery

1 evidences

Two weeks of zinc syrup (20 mg/day) in children with persistent diarrhoea shortened recovery time in underweight kids and prevented weight and serum zinc loss.

Trust comment: Randomized double-blind controlled trial with clinically meaningful outcomes in 190 high-risk children; subgroup effects reported.

Study Details

PMID:9894821
Participants:190
Impact:↓ 33% in underweight children (P=0.03); ↓27% in males (P=0.05)
Trust score:4/5

body weight during hospitalization

1 evidences

Two weeks of zinc syrup (20 mg/day) in children with persistent diarrhoea shortened recovery time in underweight kids and prevented weight and serum zinc loss.

Trust comment: Randomized double-blind controlled trial with clinically meaningful outcomes in 190 high-risk children; subgroup effects reported.

Study Details

PMID:9894821
Participants:190
Impact:maintained in zinc group vs decreased in control (5.72 → 5.70 kg vs 5.75 → 5.67 kg; control change P=0.05)
Trust score:4/5

height/weight gain

1 evidences

Weekly zinc (70 mg) increased serum zinc by 16% in preschool children selected for low/marginal nutrient status; growth effects were driven by vitamin A, not zinc.

Trust comment: Randomized factorial study but small selected sample (n=43 completed) limits generalizability; objective biomarker change for zinc robust.

Study Details

PMID:10376776
Participants:43
Impact:no significant effect attributable to zinc (vitamin A drove growth changes)
Trust score:3/5

plasma zinc concentration (response to MN supplement)

1 evidences

In HIV+ adults, inflammation lowered plasma zinc and prevented increases after a micronutrient supplement containing 15 mg zinc/day; in non-inflamed subjects plasma zinc rose ~10%.

Trust comment: Randomized supplementation with relevant biomarker data but small groups and subgroup analyses reduce certainty.

Study Details

PMID:20216563
Participants:81
Impact:↑ ≈10% in those without inflammation (P=0.023); mean change +0.95 μmol/L in MN vs −0.83 μmol/L in food-only subgroup (P=0.031)
Trust score:3/5

inflammation effect on plasma zinc

1 evidences

In HIV+ adults, inflammation lowered plasma zinc and prevented increases after a micronutrient supplement containing 15 mg zinc/day; in non-inflamed subjects plasma zinc rose ~10%.

Trust comment: Randomized supplementation with relevant biomarker data but small groups and subgroup analyses reduce certainty.

Study Details

PMID:20216563
Participants:81
Impact:inflammation associated with lower baseline plasma zinc and blocked supplement-induced increases
Trust score:3/5

H2S (hydrogen sulfide)

1 evidences

A single brushing with a zinc-containing experimental toothpaste substantially reduced sulfur compounds in morning breath compared with a non-zinc control.

Trust comment: Well-controlled randomized double-blind crossover design with clear, measured outcomes but small sample size.

Study Details

PMID:22134057
Participants:28
Impact:-68% (experimental Zn toothpaste B vs control)
Trust score:4/5

CH3SH (methyl mercaptan)

1 evidences

A single brushing with a zinc-containing experimental toothpaste substantially reduced sulfur compounds in morning breath compared with a non-zinc control.

Trust comment: Well-controlled randomized double-blind crossover design with clear, measured outcomes but small sample size.

Study Details

PMID:22134057
Participants:28
Impact:-47% (experimental Zn toothpaste B vs control)
Trust score:4/5

H2S after cysteine rinse

1 evidences

A single brushing with a zinc-containing experimental toothpaste substantially reduced sulfur compounds in morning breath compared with a non-zinc control.

Trust comment: Well-controlled randomized double-blind crossover design with clear, measured outcomes but small sample size.

Study Details

PMID:22134057
Participants:28
Impact:-48% (experimental Zn toothpaste B vs control)
Trust score:4/5

maternal serum zinc

1 evidences

Twelve weeks of maternal zinc supplementation increased maternal serum zinc, raised cord blood osteocalcin, and was associated with slightly longer neonatal birth length.

Trust comment: Double-blind randomized placebo-controlled trial with moderate sample size and statistically significant biological and clinical endpoints.

Study Details

PMID:33871218
Participants:71
Impact:+~4.0 μg/dL (55.1 → 59.1 μg/dL in supplement group; p=0.017)
Trust score:4/5

cord blood osteocalcin

1 evidences

Twelve weeks of maternal zinc supplementation increased maternal serum zinc, raised cord blood osteocalcin, and was associated with slightly longer neonatal birth length.

Trust comment: Double-blind randomized placebo-controlled trial with moderate sample size and statistically significant biological and clinical endpoints.

Study Details

PMID:33871218
Participants:71
Impact:+41.2 ng/ml (131.8 vs 90.6 ng/ml; p=0.001)
Trust score:4/5

neonatal birth length

1 evidences

Twelve weeks of maternal zinc supplementation increased maternal serum zinc, raised cord blood osteocalcin, and was associated with slightly longer neonatal birth length.

Trust comment: Double-blind randomized placebo-controlled trial with moderate sample size and statistically significant biological and clinical endpoints.

Study Details

PMID:33871218
Participants:71
Impact:+1.0 cm (median 49.3 vs 48.3 cm; p=0.004)
Trust score:4/5

hair zinc

1 evidences

Processing complementary cereal-based food to increase zinc solubility did not change infant hair zinc levels or growth between 6 and 12 months.

Trust comment: Community randomized double-blind trial with adequate sample size but the intervention was an indirect processing approach and did not alter zinc status or growth.

Study Details

PMID:16441931
Participants:158
Impact:no significant change
Trust score:3/5

infant growth (anthropometrics)

1 evidences

Processing complementary cereal-based food to increase zinc solubility did not change infant hair zinc levels or growth between 6 and 12 months.

Trust comment: Community randomized double-blind trial with adequate sample size but the intervention was an indirect processing approach and did not alter zinc status or growth.

Study Details

PMID:16441931
Participants:158
Impact:no significant change
Trust score:3/5

serum bilirubin

1 evidences

Oral zinc plus phototherapy in preterm neonates with jaundice led to lower serum bilirubin compared with phototherapy alone on days 8–10 of admission.

Trust comment: Prospective randomized clinical trial with a large sample of preterm neonates showing delayed but significant bilirubin reduction; effect sizes not fully reported in excerpt.

Study Details

PMID:33357203
Participants:200
Impact:decreased (significant on days 8–10; p=0.045, 0.027, 0.004)
Trust score:4/5

total absorbed zinc (TAZ) per 500 g meal

1 evidences

In a randomized crossover isotope study, zinc-biofortified potatoes provided ~22.5% more total absorbed zinc per meal than regular potatoes despite a lower fractional absorption.

Trust comment: Rigorous randomized crossover design using stable isotopes and careful controls; high internal validity though limited to adult women in one region.

Study Details

PMID:37648112
Participants:37
Impact:biofortified 0.49 mg vs regular 0.40 mg (+22.5% TAZ)
Trust score:5/5

diarrhea volume / ORS consumption

1 evidences

Zinc supplementation (alone or with other micronutrients) given with rehydration significantly reduced duration and volume of diarrhea in young children compared with placebo.

Trust comment: Double-blind randomized placebo-controlled trial with clear clinical outcomes and reasonable sample size; combination supplements not superior to zinc alone.

Study Details

PMID:21592508
Participants:167
Impact:decreased (supplemented groups vs placebo; p<0.0001)
Trust score:4/5

serum alpha-1-acid glycoprotein (AGP)

1 evidences

Providing biofortified wheat increased dietary zinc by ~1.5 mg/day but did not raise plasma zinc; it was associated with a reduction in an inflammation marker (AGP).

Trust comment: Large double-blind cluster RCT with good sample size, high compliance, and appropriate analyses; results robust.

Study Details

PMID:35458222
Participants:407
Impact:decrease (endline β=−4.55; p=0.042)
Trust score:5/5

ORS intake (fluid consumption)

1 evidences

A zinc-containing gel ORS increased fluid intake and reduced diarrhea duration and persistence at 72 h in young children with acute gastroenteritis.

Trust comment: Randomized controlled trial with clear endpoints but modest sample size.

Study Details

PMID:25822861
Participants:83
Impact:increased at 4 h and 24 h (significant)
Trust score:4/5

persistent diarrhea at 72 h

1 evidences

A zinc-containing gel ORS increased fluid intake and reduced diarrhea duration and persistence at 72 h in young children with acute gastroenteritis.

Trust comment: Randomized controlled trial with clear endpoints but modest sample size.

Study Details

PMID:25822861
Participants:83
Impact:fewer children with diarrhea at 72 h (p=0.028)
Trust score:4/5

cognitive/developmental outcome

1 evidences

Higher-iron formula showed lower plasma zinc and copper at 12 months (trend) but no cognitive benefit; zinc was measured as a secondary outcome.

Trust comment: Small randomized trial where zinc was a secondary measured outcome and iron (not zinc) was the intervention, limiting direct zinc-specific conclusions.

Study Details

PMID:11487753
Participants:58
Impact:no difference between groups (no benefit)
Trust score:3/5

infection (respiratory tract) count

1 evidences

Higher-iron formula showed lower plasma zinc and copper at 12 months (trend) but no cognitive benefit; zinc was measured as a secondary outcome.

Trust comment: Small randomized trial where zinc was a secondary measured outcome and iron (not zinc) was the intervention, limiting direct zinc-specific conclusions.

Study Details

PMID:11487753
Participants:58
Impact:higher in high-iron group (3.3 ±0.9 vs 2.5 ±0.9)
Trust score:3/5

percentage of days with URTI

1 evidences

Daily zinc (10 mg) reduced percentage of days with URTI, with a stronger (significant) effect after vitamin A administration.

Trust comment: Large double-blind randomized trial with frequent morbidity monitoring; some effects only evident when combined with vitamin A.

Study Details

PMID:22414819
Participants:826
Impact:reduction overall ~12% (p=0.09); after vitamin A ~20% reduction (p=0.01)
Trust score:4/5

URTI episode count/duration

1 evidences

Daily zinc (10 mg) reduced percentage of days with URTI, with a stronger (significant) effect after vitamin A administration.

Trust comment: Large double-blind randomized trial with frequent morbidity monitoring; some effects only evident when combined with vitamin A.

Study Details

PMID:22414819
Participants:826
Impact:vitamin A associated with fewer but longer episodes (reported change)
Trust score:4/5

URTI morbidity days (combined effect)

1 evidences

Daily zinc (10 mg) reduced percentage of days with URTI, with a stronger (significant) effect after vitamin A administration.

Trust comment: Large double-blind randomized trial with frequent morbidity monitoring; some effects only evident when combined with vitamin A.

Study Details

PMID:22414819
Participants:826
Impact:greater reduction when zinc given with vitamin A (significant)
Trust score:4/5

urinary lactulose:mannitol (L:M) ratio (EED marker)

1 evidences

A bundle including zinc did not improve markers of environmental enteric dysfunction (L:M ratio) or linear growth over 12–24 weeks in young Malawian children.

Trust comment: Well-conducted double-blind RCT but the combined intervention prevents isolation of zinc-specific effects.

Study Details

PMID:27807040
Participants:254
Impact:no difference (12 wk Δ≈0.071 vs 0.073; 24 wk Δ≈0.088 vs 0.080; p>0.19)
Trust score:4/5

linear growth (length/weight changes)

1 evidences

A bundle including zinc did not improve markers of environmental enteric dysfunction (L:M ratio) or linear growth over 12–24 weeks in young Malawian children.

Trust comment: Well-conducted double-blind RCT but the combined intervention prevents isolation of zinc-specific effects.

Study Details

PMID:27807040
Participants:254
Impact:no significant change between groups
Trust score:4/5

clinical recovery within 28 days

1 evidences

In COVID-19 patients, adding zinc to hydroxychloroquine did not change 28-day recovery, need for ventilation, or death.

Trust comment: Randomized multicenter clinical trial with adequate sample and clear endpoints; no effect of zinc detected.

Study Details

PMID:33247380
Participants:191
Impact:79.2% (zinc) vs 77.9% (no zinc); no significant difference (p=0.969)
Trust score:4/5

need for mechanical ventilation

1 evidences

In COVID-19 patients, adding zinc to hydroxychloroquine did not change 28-day recovery, need for ventilation, or death.

Trust comment: Randomized multicenter clinical trial with adequate sample and clear endpoints; no effect of zinc detected.

Study Details

PMID:33247380
Participants:191
Impact:no significant difference between groups (p=0.537)
Trust score:4/5

mortality (overall)

2 evidences

In COVID-19 patients, adding zinc to hydroxychloroquine did not change 28-day recovery, need for ventilation, or death.

Trust comment: Randomized multicenter clinical trial with adequate sample and clear endpoints; no effect of zinc detected.

Study Details

PMID:33247380
Participants:191
Impact:no significant difference between groups (p=0.986)
Trust score:4/5

Randomized trial of zinc (45 mg) and multivitamin/mineral (MVM) supplementation during 8 months of TB treatment in 499 patients, assessing weight gain and survival.

Trust comment: Large randomized factorial trial with clear endpoints and reported effect sizes; subgroup finding for HIV co-infected is notable but may need replication.

Study Details

PMID:16571156
Participants:499
Impact:no significant effect for Zn alone (RR 0.76; 95% CI 0.46 to 1.28) or MVM alone (RR 0.73; 95% CI 0.43 to 1.23)
Trust score:4/5

risk of anemia and micronutrient deficiencies

1 evidences

Fortified biscuits (including iodine) increased iodine and other micronutrient status and reduced anemia in primary schoolchildren and improved deworming effectiveness.

Trust comment: Large randomized, double-blind, placebo-controlled trial with clear biochemical outcomes and robust effect estimates.

Study Details

PMID:19321576
Participants:510
Impact:reduced by >40% (reported)
Trust score:5/5

restoration survival at 2 years

1 evidences

In adolescents, a zinc-reinforced glass-ionomer restorative had lower 2-year survival (85.3%) than the comparator (95.4%).

Trust comment: Randomized triple-blind clinical trial with clear outcome measures and moderate sample size showing inferior performance of the zinc-reinforced material.

Study Details

PMID:31235189
Participants:218
Impact:ChemFil Rock (zinc-reinforced) 85.3% vs Fuji IX GP 95.4% (difference −10.1 percentage points; p=0.02)
Trust score:4/5

recovery by 2 days

1 evidences

Children with cholera given 30 mg/day zinc recovered faster and had shorter diarrhoea and lower stool output than placebo.

Trust comment: Double-blind, randomized, placebo-controlled trial with clinically meaningful, statistically significant effects on diarrhoea outcomes.

Study Details

PMID:18184631
Participants:164
Impact:49% (zinc) vs 32% (placebo); absolute +17 percentage points (p=0.032)
Trust score:5/5

Diarrhea

1 evidences

Daily zinc supplementation reduced diarrhea and unexplained fever in Tanzanian preschool children but did not affect respiratory illness.

Trust comment: Large randomized, double-blind community trial with high compliance and intent-to-treat analysis; results are directly reported and statistically supported.

Study Details

PMID:22870238
Participants:592
Impact:-24% (reduced rate; HR ~0.76, 95% CI 0.60–0.96)
Trust score:5/5

Fever without localizing signs

1 evidences

Daily zinc supplementation reduced diarrhea and unexplained fever in Tanzanian preschool children but did not affect respiratory illness.

Trust comment: Large randomized, double-blind community trial with high compliance and intent-to-treat analysis; results are directly reported and statistically supported.

Study Details

PMID:22870238
Participants:592
Impact:-25% (reduced rate)
Trust score:5/5

Respiratory illness

1 evidences

Daily zinc supplementation reduced diarrhea and unexplained fever in Tanzanian preschool children but did not affect respiratory illness.

Trust comment: Large randomized, double-blind community trial with high compliance and intent-to-treat analysis; results are directly reported and statistically supported.

Study Details

PMID:22870238
Participants:592
Impact:No significant change
Trust score:5/5

lipid peroxidation (malondialdehyde)

1 evidences

In burned children, combined vitamin C+E+zinc lowered lipid peroxidation and sped wound healing compared with placebo.

Trust comment: Randomized double-blind pilot RCT but small sample size and zinc was given as part of a combined antioxidant mixture, so zinc-specific effects are not isolated.

Study Details

PMID:19692922
Participants:32
Impact:Decreased (P = 0.006)
Trust score:3/5

time to wound healing

1 evidences

In burned children, combined vitamin C+E+zinc lowered lipid peroxidation and sped wound healing compared with placebo.

Trust comment: Randomized double-blind pilot RCT but small sample size and zinc was given as part of a combined antioxidant mixture, so zinc-specific effects are not isolated.

Study Details

PMID:19692922
Participants:32
Impact:Reduced (faster healing; P < 0.001)
Trust score:3/5

Weight and length growth

1 evidences

Infants given 3 mg/day zinc showed higher hair zinc but no significant improvements in weight or length growth over 6 months.

Trust comment: Small randomized double-blind trial with objective biomarker changes (hair zinc) but limited sample size and no growth benefit demonstrated.

Study Details

PMID:18560697
Participants:31
Impact:No significant change
Trust score:3/5

Hair zinc concentration

2 evidences

Infants given 3 mg/day zinc showed higher hair zinc but no significant improvements in weight or length growth over 6 months.

Trust comment: Small randomized double-blind trial with objective biomarker changes (hair zinc) but limited sample size and no growth benefit demonstrated.

Study Details

PMID:18560697
Participants:31
Impact:Increased (significant at 1, 2, and 6 months)
Trust score:3/5

Daily preventive zinc (7–10 mg/day) raised plasma zinc and (exploratorily) nail zinc but did not change hair zinc in young Laotian children after ~9 months.

Trust comment: Large randomized, double-blind, placebo-controlled trial with standardized sample collection and appropriate analyses; nail results exploratory due to comparator issue.

Study Details

PMID:32356207
Participants:492
Impact:no change (no significant difference between PZ, MNP, and control)
Trust score:5/5

Time to sputum smear/culture conversion

1 evidences

Adjunctive vitamin A plus zinc for 8 weeks did not change time to sputum smear or culture conversion or weight gain in adults with pulmonary TB.

Trust comment: Moderately sized randomized controlled trial with objective microbiological endpoints; null results reported clearly.

Study Details

PMID:21068353
Participants:154
Impact:No significant difference
Trust score:4/5

Diarrhoeal disease

1 evidences

Zinc supplementation (10 mg) in children with PEM reduced in-hospital mortality and several morbidity outcomes and improved short-term weight status post-discharge.

Trust comment: Large randomized, double-blind clinical trial in a high-risk population with clinically meaningful outcome reductions reported.

Study Details

PMID:14725411
Participants:300
Impact:Reduced (significant)
Trust score:4/5

Respiratory morbidity

1 evidences

Zinc supplementation (10 mg) in children with PEM reduced in-hospital mortality and several morbidity outcomes and improved short-term weight status post-discharge.

Trust comment: Large randomized, double-blind clinical trial in a high-risk population with clinically meaningful outcome reductions reported.

Study Details

PMID:14725411
Participants:300
Impact:Reduced (significant)
Trust score:4/5

Zinc intake correlation with plasma zinc

1 evidences

In obese adolescents on low-energy diets, plasma zinc did not change over 12 weeks; plasma zinc correlated modestly with zinc intake and protein intake, and phytate:zinc ratio indicated lower zinc bioavailability with high-carb diet.

Trust comment: Randomized dietary trial adequately measuring zinc intake/bioavailability but not a zinc supplementation trial and sample-specific to obese insulin-resistant adolescents.

Study Details

PMID:27750250
Participants:87
Impact:Positive correlation (r = 0.235, P = 0.042)
Trust score:3/5

Zinc bioavailability (phytate:zinc molar ratio)

1 evidences

In obese adolescents on low-energy diets, plasma zinc did not change over 12 weeks; plasma zinc correlated modestly with zinc intake and protein intake, and phytate:zinc ratio indicated lower zinc bioavailability with high-carb diet.

Trust comment: Randomized dietary trial adequately measuring zinc intake/bioavailability but not a zinc supplementation trial and sample-specific to obese insulin-resistant adolescents.

Study Details

PMID:27750250
Participants:87
Impact:Higher (worse bioavailability) in high-carbohydrate diet (9.4 vs 7.4)
Trust score:3/5

zinc intake from complementary foods

1 evidences

Introducing pureed beef as first complementary food increased zinc intake and was associated with greater head growth; blood zinc did not differ between groups.

Trust comment: Randomized trial with objective biomarker measures and longitudinal follow-up, moderate sample size.

Study Details

PMID:16456417
Participants:88
Impact:+1.3 mg/day (1.9 vs 0.6 mg/day at 7 months)
Trust score:4/5

head circumference growth

1 evidences

Introducing pureed beef as first complementary food increased zinc intake and was associated with greater head growth; blood zinc did not differ between groups.

Trust comment: Randomized trial with objective biomarker measures and longitudinal follow-up, moderate sample size.

Study Details

PMID:16456417
Participants:88
Impact:greater increase (7→12 months) in meat group vs cereal
Trust score:4/5

baseline serum zinc (type 2 diabetics vs controls)

1 evidences

Type 2 diabetics had lower serum zinc than controls; 3 months of oral zinc supplementation raised serum zinc and reduced HbA1c% in supplemented patients.

Trust comment: Controlled supplementation trial but single-blind and limited reporting of effect sizes for some outcomes.

Study Details

PMID:16532095
Participants:101
Impact:-14.5 µg/dL (68.9 vs 83.4 µg/dL)
Trust score:3/5

serum zinc after supplementation

1 evidences

Type 2 diabetics had lower serum zinc than controls; 3 months of oral zinc supplementation raised serum zinc and reduced HbA1c% in supplemented patients.

Trust comment: Controlled supplementation trial but single-blind and limited reporting of effect sizes for some outcomes.

Study Details

PMID:16532095
Participants:101
Impact:increase after 3 months (significant)
Trust score:3/5

plasma vitamin A (retinol)

1 evidences

Six months of zinc supplementation increased plasma vitamin A (dose- and time-dependent) but did not affect vitamin E/cholesterol ratio or erythrocyte folates.

Trust comment: Large randomized allocation and repeated biochemical measures support moderate–high reliability of findings.

Study Details

PMID:17622255
Participants:387
Impact:increase at 6 months (15 mg Zn/day: P<0.05; 30 mg Zn/day: P<0.0001; dose-dependent)
Trust score:4/5

plasma vitamin E / cholesterol ratio

1 evidences

Six months of zinc supplementation increased plasma vitamin A (dose- and time-dependent) but did not affect vitamin E/cholesterol ratio or erythrocyte folates.

Trust comment: Large randomized allocation and repeated biochemical measures support moderate–high reliability of findings.

Study Details

PMID:17622255
Participants:387
Impact:no change
Trust score:4/5

erythrocyte folates

1 evidences

Six months of zinc supplementation increased plasma vitamin A (dose- and time-dependent) but did not affect vitamin E/cholesterol ratio or erythrocyte folates.

Trust comment: Large randomized allocation and repeated biochemical measures support moderate–high reliability of findings.

Study Details

PMID:17622255
Participants:387
Impact:no change
Trust score:4/5

time to recovery (pneumonia)

1 evidences

Oral zinc as adjunctive therapy did not shorten time to recovery or significantly reduce treatment failure in children with radiologically confirmed pneumonia.

Trust comment: Randomized controlled trial with radiologic confirmation and reasonable sample size; secondary analysis but outcomes clinically relevant.

Study Details

PMID:28575379
Participants:212
Impact:no significant difference (median ~84 h zinc vs ~85 h placebo)
Trust score:4/5

treatment failure (absolute risk reduction)

1 evidences

Oral zinc as adjunctive therapy did not shorten time to recovery or significantly reduce treatment failure in children with radiologically confirmed pneumonia.

Trust comment: Randomized controlled trial with radiologic confirmation and reasonable sample size; secondary analysis but outcomes clinically relevant.

Study Details

PMID:28575379
Participants:212
Impact:5.2% (95% CI -4.8, 15.1) — not statistically significant
Trust score:4/5

high probable sepsis (HPS) after 10 days

1 evidences

In preterm neonates with late-onset sepsis, 10 days of oral zinc plus antibiotics improved clinical sepsis scores and reduced CRP and procalcitonin versus placebo plus antibiotics.

Trust comment: Prospective randomized clinical trial with clear clinical and laboratory endpoints and a reasonable sample size.

Study Details

PMID:33285602
Participants:180
Impact:reduced (1/90 vs 4/90; p=0.045)
Trust score:4/5

procalcitonin (PCT)

1 evidences

In preterm neonates with late-onset sepsis, 10 days of oral zinc plus antibiotics improved clinical sepsis scores and reduced CRP and procalcitonin versus placebo plus antibiotics.

Trust comment: Prospective randomized clinical trial with clear clinical and laboratory endpoints and a reasonable sample size.

Study Details

PMID:33285602
Participants:180
Impact:0.39±0.13 vs 0.61±0.22 ng/mL after 10 days (p=0.044); ~0.22 ng/mL lower
Trust score:4/5

hemoglobin (Hgb) levels

1 evidences

All three oral iron preparations (including an iron–zinc combination) raised hemoglobin levels by weeks 4 and 8; iron–zinc performed similarly to other formulations.

Trust comment: Randomized trial but small sample and limited numeric reporting of between-group differences for the Fe–Zn arm.

Study Details

PMID:26200522
Participants:60
Impact:increased at 4 and 8 weeks in Fe–Zn group (statistically significant; similar efficacy to other iron preparations)
Trust score:3/5

nail zinc concentration

1 evidences

Daily preventive zinc (7–10 mg/day) raised plasma zinc and (exploratorily) nail zinc but did not change hair zinc in young Laotian children after ~9 months.

Trust comment: Large randomized, double-blind, placebo-controlled trial with standardized sample collection and appropriate analyses; nail results exploratory due to comparator issue.

Study Details

PMID:32356207
Participants:492
Impact:modest increase vs therapeutic-zinc group: PZ +5.4 μg/g (115.8 vs 110.4 μg/g), MNP +7.4 μg/g (117.8 vs 110.4 μg/g) (exploratory comparison)
Trust score:5/5

diarrhea recurrence

1 evidences

In hospitalized children 5–12 years with acute dehydrating diarrhea, 40 mg/day zinc for 14 days did not shorten diarrhea duration or significantly change rehydration, hospitalization time, or recurrence.

Trust comment: Randomized placebo-controlled trial with clear clinical endpoints but modest sample size and limited to hospitalized older children.

Study Details

PMID:24673165
Participants:134
Impact:no statistically significant reduction (risk ratio 0.65, 95% CI 0.37–1.23, p=0.11)
Trust score:4/5

sperm quality (count, motility, morphology)

1 evidences

In 125 heavy male smokers with infertility, zinc therapy improved sperm quality measures and shifted cytokine profiles (increased IL-4, decreased TNF-α and IFN-γ); supporting an immunomodulatory role of zinc.

Trust comment: Clinical cohort of smokers with infertility showing benefit, but study design details (randomization/blinding) and effect sizes not fully described in the provided excerpt.

Study Details

PMID:10543576
Participants:125
Impact:improved with zinc therapy (magnitude not specified in provided text)
Trust score:3/5

cytokine profile

1 evidences

In 125 heavy male smokers with infertility, zinc therapy improved sperm quality measures and shifted cytokine profiles (increased IL-4, decreased TNF-α and IFN-γ); supporting an immunomodulatory role of zinc.

Trust comment: Clinical cohort of smokers with infertility showing benefit, but study design details (randomization/blinding) and effect sizes not fully described in the provided excerpt.

Study Details

PMID:10543576
Participants:125
Impact:IL-4 increased; TNF-alpha and IFN-gamma decreased
Trust score:3/5

Gingival severity (bleeding)

1 evidences

A mouthwash containing an amine compound + zinc lactate + fluoride reduced gum inflammation and dental plaque more than a non‑active control over 6 months.

Trust comment: Well‑conducted triple‑blind RCT with per‑protocol analysis (78 completers); industry sponsorship may introduce bias.

Study Details

PMID:38217757
Participants:78
Impact:-81.1% (AZF vs control) at 6 months
Trust score:4/5

plasma homocysteine

1 evidences

Zinc supplementation in zinc‑deficient ESRD patients increased serum zinc and substantially reduced plasma homocysteine vs placebo over ~6 weeks.

Trust comment: Double‑blind RCT in a defined zinc‑deficient ESRD population with clear biochemical endpoints; short duration but robust internal validity.

Study Details

PMID:23475369
Participants:100
Impact:Significant reduction vs placebo (p<0.0001)
Trust score:4/5

Serum glucose / HbA1c

1 evidences

Twelve weeks of zinc (40 mg/day) ± flaxseed oil in postmenopausal women with type 2 diabetes produced no significant changes in glycemic markers or zinc transporter/metallothionein gene expression.

Trust comment: Randomized double‑blind trial but small sample (n=48) limits power to detect modest effects.

Study Details

PMID:25156968
Participants:48
Impact:no significant change over 12 weeks
Trust score:3/5

HOMA‑IR (insulin resistance)

1 evidences

Twelve weeks of zinc (40 mg/day) ± flaxseed oil in postmenopausal women with type 2 diabetes produced no significant changes in glycemic markers or zinc transporter/metallothionein gene expression.

Trust comment: Randomized double‑blind trial but small sample (n=48) limits power to detect modest effects.

Study Details

PMID:25156968
Participants:48
Impact:no significant change over 12 weeks
Trust score:3/5

Zinc transporter / metallothionein gene expression

2 evidences

Twelve weeks of zinc (40 mg/day) ± flaxseed oil in postmenopausal women with type 2 diabetes produced no significant changes in glycemic markers or zinc transporter/metallothionein gene expression.

Trust comment: Randomized double‑blind trial but small sample (n=48) limits power to detect modest effects.

Study Details

PMID:25156968
Participants:48
Impact:no significant fold‑change over 12 weeks
Trust score:3/5

48 postmenopausal women with type 2 diabetes received zinc (40 mg/day) ± ALA or placebo for 12 weeks; zinc raised plasma zinc but did not change inflammatory marker concentrations.

Trust comment: Randomized double-blind placebo-controlled trial with clearly reported endpoints but modest sample size and specialized population.

Study Details

PMID:23643522
Participants:48
Impact:no significant fold-change overall; altered correlations with zinc treatment (reported associations)
Trust score:4/5

Birth length

1 evidences

Prenatal zinc supplementation produced a small increase in newborn length but had no effect on birth weight, neonatal morbidity, or mortality.

Trust comment: Large double‑blind randomized trial with high sample size and neonatal outcomes measured; effects are small and clinically modest.

Study Details

PMID:24220161
Participants:1956
Impact:+0.3 cm with zinc vs placebo (48.8 vs 48.5 cm, p=0.04)
Trust score:4/5

Neonatal morbidity/mortality

1 evidences

Prenatal zinc supplementation produced a small increase in newborn length but had no effect on birth weight, neonatal morbidity, or mortality.

Trust comment: Large double‑blind randomized trial with high sample size and neonatal outcomes measured; effects are small and clinically modest.

Study Details

PMID:24220161
Participants:1956
Impact:no significant effect
Trust score:4/5

Cure rate (NZCS)

1 evidences

Topical nitric‑zinc complex solution cured about 56.6% of plantar warts but had a slightly lower cure rate and required more treatment applications than cryotherapy.

Trust comment: Randomized controlled trial with modest sample size; topical zinc‑containing product evaluated but effect sizes modest and comparators active.

Study Details

PMID:37930111
Participants:62
Impact:56.6% cured (vs cryotherapy 65.5%)
Trust score:3/5

Number of treatment applications

1 evidences

Topical nitric‑zinc complex solution cured about 56.6% of plantar warts but had a slightly lower cure rate and required more treatment applications than cryotherapy.

Trust comment: Randomized controlled trial with modest sample size; topical zinc‑containing product evaluated but effect sizes modest and comparators active.

Study Details

PMID:37930111
Participants:62
Impact:NZCS required more applications (mean 4.8) than cryotherapy (mean 3.6); p<0.01
Trust score:3/5

Cure rate difference

1 evidences

Topical nitric‑zinc complex solution cured about 56.6% of plantar warts but had a slightly lower cure rate and required more treatment applications than cryotherapy.

Trust comment: Randomized controlled trial with modest sample size; topical zinc‑containing product evaluated but effect sizes modest and comparators active.

Study Details

PMID:37930111
Participants:62
Impact:cryotherapy ~9 percentage points higher than NZCS (65.5% vs 56.6%)
Trust score:3/5

pregnancy outcome (incl. pregnancy-induced hypertension and blood pressure)

1 evidences

In pregnant African-American women, zinc supplementation did not change pregnancy outcomes, blood pressure, or ACE activity.

Trust comment: Human nested trial with reasonable sample but authors note limited power for some comparisons, so results are moderately reliable.

Study Details

PMID:8841206
Participants:191
Impact:no significant change
Trust score:3/5

Plasma ACE activity

1 evidences

In pregnant African-American women, zinc supplementation did not change pregnancy outcomes, blood pressure, or ACE activity.

Trust comment: Human nested trial with reasonable sample but authors note limited power for some comparisons, so results are moderately reliable.

Study Details

PMID:8841206
Participants:191
Impact:no significant change
Trust score:3/5

plasma and erythrocyte zinc concentrations

2 evidences

In pregnant African-American women, zinc supplementation did not change pregnancy outcomes, blood pressure, or ACE activity.

Trust comment: Human nested trial with reasonable sample but authors note limited power for some comparisons, so results are moderately reliable.

Study Details

PMID:8841206
Participants:191
Impact:no significant change
Trust score:3/5

In a 4-month trial of rosuvastatin with or without zinc supplementation, zinc had no measurable effect on zinc status markers, SOD activity, or MT gene expression.

Trust comment: Randomized double-blind clinical trial in patients, but relatively small sample size limits power for some endpoints.

Study Details

PMID:24560278
Participants:54
Impact:no significant change with zinc supplementation (no meaningful effect)
Trust score:4/5

morbidity during 12-week follow-up

1 evidences

In children with acute diarrhea, zinc (alone or with copper) did not change short-term morbidity or growth over 12 weeks.

Trust comment: Large (n=724), double-blind randomized controlled trial, providing high-quality negative evidence for short-term benefit in this setting.

Study Details

PMID:22926212
Participants:724
Impact:no significant change
Trust score:5/5

growth over 12-week follow-up

1 evidences

In children with acute diarrhea, zinc (alone or with copper) did not change short-term morbidity or growth over 12 weeks.

Trust comment: Large (n=724), double-blind randomized controlled trial, providing high-quality negative evidence for short-term benefit in this setting.

Study Details

PMID:22926212
Participants:724
Impact:no significant change
Trust score:5/5

olfactory function recovery

1 evidences

Zinc gluconate treatment increased rates of smell recovery after head injury compared with no treatment.

Trust comment: Prospective randomized study with moderate sample sizes per group showing significant improvement in smell recovery with zinc.

Study Details

PMID:25715353
Participants:145
Impact:increased recovery rate: zinc alone 25.7% vs no treatment 2.7% (≈+23 percentage points); zinc+steroid 28.2% (≈+25.5 pp)
Trust score:4/5

olfactory bulb volume

1 evidences

Zinc gluconate treatment increased rates of smell recovery after head injury compared with no treatment.

Trust comment: Prospective randomized study with moderate sample sizes per group showing significant improvement in smell recovery with zinc.

Study Details

PMID:25715353
Participants:145
Impact:no significant difference between improved vs non-improved patients
Trust score:4/5

growth (weight/length and velocity)

1 evidences

In healthy term breastfed U.S. infants, daily 5 mg zinc supplementation produced no changes in growth, morbidity, or motor development.

Trust comment: Randomized double-blind trial but relatively small (70 completers), so negative findings are reasonably reliable for this population.

Study Details

PMID:16960174
Participants:70
Impact:no significant change
Trust score:4/5

morbidity (infections)

1 evidences

In healthy term breastfed U.S. infants, daily 5 mg zinc supplementation produced no changes in growth, morbidity, or motor development.

Trust comment: Randomized double-blind trial but relatively small (70 completers), so negative findings are reasonably reliable for this population.

Study Details

PMID:16960174
Participants:70
Impact:no significant change
Trust score:4/5

gross motor development

1 evidences

In healthy term breastfed U.S. infants, daily 5 mg zinc supplementation produced no changes in growth, morbidity, or motor development.

Trust comment: Randomized double-blind trial but relatively small (70 completers), so negative findings are reasonably reliable for this population.

Study Details

PMID:16960174
Participants:70
Impact:no significant change
Trust score:4/5

volatile sulfide compound (VSC) levels

1 evidences

In healthy volunteers, a palatal tablet containing zinc reduced volatile sulfide compounds (VSC); herbal formulation was more effective than zinc.

Trust comment: Small controlled study showing biochemical/clinical reductions in malodor markers; zinc had significant VSC reduction but herbal was superior.

Study Details

PMID:18468761
Participants:56
Impact:significant reduction with zinc tablet (p=0.024)
Trust score:3/5

oral malodor (odor judge scores)

1 evidences

In healthy volunteers, a palatal tablet containing zinc reduced volatile sulfide compounds (VSC); herbal formulation was more effective than zinc.

Trust comment: Small controlled study showing biochemical/clinical reductions in malodor markers; zinc had significant VSC reduction but herbal was superior.

Study Details

PMID:18468761
Participants:56
Impact:reduced (herbal formulation > zinc; zinc produced reduction but less than herbal; specific p for zinc not reported for scores)
Trust score:3/5

diarrhoea episodes (number)

1 evidences

Children given 20 mg/day zinc for two weeks during persistent diarrhea had fewer and shorter subsequent diarrhoeal episodes and greater linear growth in underweight children over 12 weeks.

Trust comment: Follow-up of a randomized controlled trial with clear, significant clinical benefits in morbidity and growth among malnourished children.

Study Details

PMID:17615905
Participants:154
Impact:reduced by ~38% (0.53 vs 0.86 episodes; p<0.05)
Trust score:4/5

duration of diarrhoea episodes

1 evidences

Children given 20 mg/day zinc for two weeks during persistent diarrhea had fewer and shorter subsequent diarrhoeal episodes and greater linear growth in underweight children over 12 weeks.

Trust comment: Follow-up of a randomized controlled trial with clear, significant clinical benefits in morbidity and growth among malnourished children.

Study Details

PMID:17615905
Participants:154
Impact:reduced by ~44% (1.9 vs 3.4 days; p<0.05)
Trust score:4/5

linear growth in underweight children

1 evidences

Children given 20 mg/day zinc for two weeks during persistent diarrhea had fewer and shorter subsequent diarrhoeal episodes and greater linear growth in underweight children over 12 weeks.

Trust comment: Follow-up of a randomized controlled trial with clear, significant clinical benefits in morbidity and growth among malnourished children.

Study Details

PMID:17615905
Participants:154
Impact:increased by ~24% (30.2 mm vs 24.4 mm cumulative gain; p<0.03)
Trust score:4/5

erythrocyte superoxide dismutase (SOD) activity

1 evidences

In a 4-month trial of rosuvastatin with or without zinc supplementation, zinc had no measurable effect on zinc status markers, SOD activity, or MT gene expression.

Trust comment: Randomized double-blind clinical trial in patients, but relatively small sample size limits power for some endpoints.

Study Details

PMID:24560278
Participants:54
Impact:no significant effect (P=0.201)
Trust score:4/5

MT1F and MT2A gene expression

1 evidences

In a 4-month trial of rosuvastatin with or without zinc supplementation, zinc had no measurable effect on zinc status markers, SOD activity, or MT gene expression.

Trust comment: Randomized double-blind clinical trial in patients, but relatively small sample size limits power for some endpoints.

Study Details

PMID:24560278
Participants:54
Impact:no significant change with zinc supplementation
Trust score:4/5

language development

1 evidences

In Zanzibari infants, iron+folic acid with or without zinc improved motor development; zinc alone was associated with worse language development in the 10–14 month group.

Trust comment: Substudy of a randomized, placebo-controlled 2×2 factorial trial with longitudinal measures, giving moderate confidence in observed effects.

Study Details

PMID:23725789
Participants:247
Impact:negative effect with zinc alone in children aged 10–14 months (FeFA alone also negative for language in both age groups)
Trust score:4/5

anti-HSP27 antibody titer

1 evidences

In transfusion-dependent beta-thalassemia major patients, 9 months of daily zinc (30 mg) decreased anti-HSP27 antibody titers compared with placebo.

Trust comment: Double-blind placebo-controlled clinical trial with clear biomarker outcome, though moderate sample size.

Study Details

PMID:23683800
Participants:64
Impact:decreased (zinc group: 0.44 ± 0.15 to 0.40 ± 0.18 vs placebo increase; between-group P = 0.01)
Trust score:4/5

lymphocyte proliferation

1 evidences

A 14-day zinc course in children with shigellosis increased lymphocyte proliferation and Ipa-specific plasma IgG, with no significant effects on measured cytokines.

Trust comment: Randomized double-blind placebo-controlled trial in children with clear immunologic endpoints, moderate sample size.

Study Details

PMID:14985220
Participants:56
Impact:increased in zinc group (P = 0.002)
Trust score:4/5

Ipa-specific plasma IgG

1 evidences

A 14-day zinc course in children with shigellosis increased lymphocyte proliferation and Ipa-specific plasma IgG, with no significant effects on measured cytokines.

Trust comment: Randomized double-blind placebo-controlled trial in children with clear immunologic endpoints, moderate sample size.

Study Details

PMID:14985220
Participants:56
Impact:significantly higher at day 30 in zinc group
Trust score:4/5

ADHD symptom score (teacher-rated CGI)

1 evidences

In this 6-week pilot RCT adding zinc (10 mg/day) to methylphenidate, plasma zinc decline was smaller with supplementation and teachers noted a non-significant improvement in ADHD scores.

Trust comment: Small, preliminary randomized double-blind trial with limited power and some non-significant clinical findings.

Study Details

PMID:22696891
Participants:40
Impact:apparent improvement with zinc by teachers (non-significant, p = 0.07)
Trust score:3/5

Malaria incidence

2 evidences

In young Burkinabe children, adding 5 or 10 mg zinc to daily SQ-LNS or giving a 5 mg zinc tablet did not reduce diarrhoea, malaria, fever, or respiratory infections compared with SQ-LNS without added zinc.

Trust comment: Large, double-blind, cluster-randomised trial with rigorous surveillance and appropriate analyses; results directly assess zinc interventions.

Study Details

PMID:26362661
Participants:2364
Impact:no significant change
Trust score:5/5

Daily zinc supplementation did not reduce malaria episodes but increased plasma zinc and markedly reduced zinc deficiency.

Trust comment: Large randomized, double-blind trial with high adherence, prespecified analyses, and clinically measured endpoints.

Study Details

PMID:22131908
Participants:592
Impact:−1% (HR 0.99; 95% CI 0.82–1.18)
Trust score:5/5

Infant mortality (infectious disease)

1 evidences

Zinc supplementation in full-term small-for-gestational-age infants substantially reduced mortality (primarily infectious disease deaths).

Trust comment: Large randomized, double-blind controlled trial with intent-to-treat survival analysis showing a significant mortality reduction.

Study Details

PMID:11731649
Participants:1154
Impact:−68% (rate ratio 0.32; 95% CI 0.12–0.89)
Trust score:5/5

Cognitive development (BSID-III)

1 evidences

In the subsample assessed at ~15 months, daily zinc (with or without multivitamins) did not improve cognitive, language, or motor development scores.

Trust comment: Large randomized trial overall, but developmental outcomes were assessed in a small subsample, limiting power to detect small effects.

Study Details

PMID:27189038
Participants:247
Impact:No significant change
Trust score:4/5

Language development (BSID-III)

1 evidences

In the subsample assessed at ~15 months, daily zinc (with or without multivitamins) did not improve cognitive, language, or motor development scores.

Trust comment: Large randomized trial overall, but developmental outcomes were assessed in a small subsample, limiting power to detect small effects.

Study Details

PMID:27189038
Participants:247
Impact:No significant change
Trust score:4/5

Motor development (BSID-III)

1 evidences

In the subsample assessed at ~15 months, daily zinc (with or without multivitamins) did not improve cognitive, language, or motor development scores.

Trust comment: Large randomized trial overall, but developmental outcomes were assessed in a small subsample, limiting power to detect small effects.

Study Details

PMID:27189038
Participants:247
Impact:No significant change
Trust score:4/5

alanine aminotransferase (ALT)

1 evidences

Children with NASH took zinc for 16 weeks and had lower liver enzyme and inflammation and higher HDL, but no change in liver fat on ultrasound.

Trust comment: Randomized, placebo-controlled trial in children with registration and clear endpoints but modest sample size.

Study Details

PMID:37989929
Participants:60
Impact:decreased (significant)
Trust score:4/5

high-sensitivity C-reactive protein (hs-CRP)

1 evidences

Children with NASH took zinc for 16 weeks and had lower liver enzyme and inflammation and higher HDL, but no change in liver fat on ultrasound.

Trust comment: Randomized, placebo-controlled trial in children with registration and clear endpoints but modest sample size.

Study Details

PMID:37989929
Participants:60
Impact:decreased (significant)
Trust score:4/5

total stool count

1 evidences

In young children with acute diarrhea, zinc given with ORS or as syrup reduced stool output and severity measures but had mixed effects on duration.

Trust comment: Large, double-blind randomized controlled trial with robust sample size and clear outcomes.

Study Details

PMID:12410197
Participants:1219
Impact:reduced (zinc-ORS rate ratio 0.83; zinc-syrup rate ratio 0.73)
Trust score:5/5

proportion with watery stools

1 evidences

In young children with acute diarrhea, zinc given with ORS or as syrup reduced stool output and severity measures but had mixed effects on duration.

Trust comment: Large, double-blind randomized controlled trial with robust sample size and clear outcomes.

Study Details

PMID:12410197
Participants:1219
Impact:reduced (odds ratio 0.61 for zinc-ORS)
Trust score:5/5

diarrheal duration

1 evidences

In young children with acute diarrhea, zinc given with ORS or as syrup reduced stool output and severity measures but had mixed effects on duration.

Trust comment: Large, double-blind randomized controlled trial with robust sample size and clear outcomes.

Study Details

PMID:12410197
Participants:1219
Impact:modestly reduced with zinc syrup (relative hazard 0.89); no significant change with zinc-ORS
Trust score:5/5

incidence of acute otitis media (AOM)

1 evidences

Children with recurrent ear infections given a propolis-plus-zinc suspension had fewer new AOM episodes over 3 months than controls.

Trust comment: Randomized, blinded trial showing statistically significant reductions but uses combined propolis+zinc intervention and modest sample size.

Study Details

PMID:20646352
Participants:122
Impact:reduced (50.8% vs 70.5%; p=0.04)
Trust score:4/5

episodes per child per month

1 evidences

Children with recurrent ear infections given a propolis-plus-zinc suspension had fewer new AOM episodes over 3 months than controls.

Trust comment: Randomized, blinded trial showing statistically significant reductions but uses combined propolis+zinc intervention and modest sample size.

Study Details

PMID:20646352
Participants:122
Impact:reduced (0.23 vs 0.34; 32% reduction; p=0.03)
Trust score:4/5

requirement of higher-line antibiotics

1 evidences

Neonates with probable sepsis given zinc plus standard care had no significant change in mortality, hospital stay, or need for higher-line antibiotics.

Trust comment: Well-powered double-blind RCT with clear negative findings and balanced baseline characteristics.

Study Details

PMID:23255688
Participants:614
Impact:no significant difference (13.35% vs 12.05%; p=0.628)
Trust score:4/5

weight gain (first 3 months)

1 evidences

Zinc improved weight gain and lean mass measures during the first 3 months but those benefits did not persist over the full 12 months.

Trust comment: Randomized, placebo-controlled trial with moderate sample size but later confounding by a food program that likely affected long-term outcomes.

Study Details

PMID:9023466
Participants:313
Impact:increased (0.51 kg vs 0.14 kg; p=0.01)
Trust score:4/5

weight-for-age Z-score (first 3 months)

1 evidences

Zinc improved weight gain and lean mass measures during the first 3 months but those benefits did not persist over the full 12 months.

Trust comment: Randomized, placebo-controlled trial with moderate sample size but later confounding by a food program that likely affected long-term outcomes.

Study Details

PMID:9023466
Participants:313
Impact:improved (-0.08 vs -0.14; p=0.01)
Trust score:4/5

arm muscle area-for-age Z-score (first 3 months)

1 evidences

Zinc improved weight gain and lean mass measures during the first 3 months but those benefits did not persist over the full 12 months.

Trust comment: Randomized, placebo-controlled trial with moderate sample size but later confounding by a food program that likely affected long-term outcomes.

Study Details

PMID:9023466
Participants:313
Impact:increased (0.10 vs 0.01; p=0.03)
Trust score:4/5

duration of clinical pneumonia signs

1 evidences

In hospitalized young children with severe pneumonia, adjunct zinc did not shorten clinical signs or hospital stay overall and was linked to longer pneumonia duration in the hot season.

Trust comment: Randomized, double-blind, placebo-controlled trial with clear null overall results but a season-specific adverse signal.

Study Details

PMID:16685051
Participants:299
Impact:no overall change; longer duration in hot season with zinc (p=0.015)
Trust score:4/5

ulcer size (length and width)

1 evidences

Diabetic patients with foot ulcers given zinc for 12 weeks had smaller ulcers and improved blood sugar control, insulin resistance, HDL, and inflammation markers versus placebo.

Trust comment: Small randomized, double-blind trial showing multiple metabolic and wound-healing benefits, but limited sample size.

Study Details

PMID:28395131
Participants:60
Impact:reduced (length change -1.5 cm vs -0.9 cm; width change -1.4 cm vs -0.8 cm; p=0.02)
Trust score:4/5

insulin resistance (HOMA-IR) / HbA1c

1 evidences

Diabetic patients with foot ulcers given zinc for 12 weeks had smaller ulcers and improved blood sugar control, insulin resistance, HDL, and inflammation markers versus placebo.

Trust comment: Small randomized, double-blind trial showing multiple metabolic and wound-healing benefits, but limited sample size.

Study Details

PMID:28395131
Participants:60
Impact:improved (HOMA-IR -3.9 vs +0.8; HbA1c -0.5% vs -0.1%; p≤0.01)
Trust score:4/5

infant impetigo incidence

1 evidences

Pregnant women given 30 mg zinc daily from mid-pregnancy to delivery had infants followed to 6 months; maternal zinc reduced infant skin infections.

Trust comment: Large double-blind randomized trial with clear outcome measures and significant results; well conducted and reported.

Study Details

PMID:22189527
Participants:420
Impact:10.6% vs 19.6% (−9.0 percentage points); incidence rate −54% (P=0.01)
Trust score:4/5

male infant impetigo incidence (subgroup)

1 evidences

Pregnant women given 30 mg zinc daily from mid-pregnancy to delivery had infants followed to 6 months; maternal zinc reduced infant skin infections.

Trust comment: Large double-blind randomized trial with clear outcome measures and significant results; well conducted and reported.

Study Details

PMID:22189527
Participants:420
Impact:64% reduction in incidence rate (male infants)
Trust score:4/5

mean birth weight

2 evidences

Large cluster RCT of antenatal micronutrient regimens found folic acid–iron reduced low birthweight; folic acid–iron–zinc showed no additional benefit over control for birth size.

Trust comment: Large, double-blind cluster RCT with thousands enrolled; zinc was given in combination so isolated zinc effects are not separable.

Study Details

PMID:12637400
Participants:4130
Impact:Multiple micronutrients: +64 g (95% CI 12 to 115 g); folic acid–iron: +37 g (−16 to 90 g); folic acid–iron–zinc: no effect vs control
Trust score:4/5

Randomized trial in pregnant women with low Zn compared 30 mg Zn, Zn+multivitamin, and placebo from recruitment until 1 week postpartum; zinc reduced several pregnancy and early neonatal complications but not mean birth weight.

Trust comment: Large randomized controlled trial in Zn-deficient pregnant women with multiple clinically relevant outcomes and clear effect estimates.

Study Details

PMID:26099195
Participants:675
Impact:No significant difference (mean ~2922–2938 g; P=0.88)
Trust score:4/5

second- and third-stage pregnancy complications

1 evidences

Randomized trial in pregnant women with low Zn compared 30 mg Zn, Zn+multivitamin, and placebo from recruitment until 1 week postpartum; zinc reduced several pregnancy and early neonatal complications but not mean birth weight.

Trust comment: Large randomized controlled trial in Zn-deficient pregnant women with multiple clinically relevant outcomes and clear effect estimates.

Study Details

PMID:26099195
Participants:675
Impact:Zn alone RR 0.43 (57% reduction); Zn+multivitamin RR 0.54
Trust score:4/5

early neonatal morbidity

1 evidences

Randomized trial in pregnant women with low Zn compared 30 mg Zn, Zn+multivitamin, and placebo from recruitment until 1 week postpartum; zinc reduced several pregnancy and early neonatal complications but not mean birth weight.

Trust comment: Large randomized controlled trial in Zn-deficient pregnant women with multiple clinically relevant outcomes and clear effect estimates.

Study Details

PMID:26099195
Participants:675
Impact:Zn group RR 0.23 (≈77% reduction); Zn+multivitamin RR 0.25
Trust score:4/5

child temperament score

1 evidences

Cluster-randomized trial of daily zinc (10 mg), iron–folic acid, combination, or placebo in infants/toddlers over ~1 year found no overall effect of zinc on temperament or eating behaviors, except improved eating behavior among children with baseline iron-deficiency anemia.

Trust comment: Large cluster-randomized, double-masked trial with good retention and appropriate analyses; outcomes are caregiver-reported which is a limitation.

Study Details

PMID:25821959
Participants:569
Impact:No significant change with zinc (adjusted β = −0.03; 95% CI −0.3, 0.2)
Trust score:4/5

child eating behavior score (overall)

1 evidences

Cluster-randomized trial of daily zinc (10 mg), iron–folic acid, combination, or placebo in infants/toddlers over ~1 year found no overall effect of zinc on temperament or eating behaviors, except improved eating behavior among children with baseline iron-deficiency anemia.

Trust comment: Large cluster-randomized, double-masked trial with good retention and appropriate analyses; outcomes are caregiver-reported which is a limitation.

Study Details

PMID:25821959
Participants:569
Impact:No significant change with zinc (adjusted β = −0.14; 95% CI −0.3, 0.04)
Trust score:4/5

eating behavior (iron-deficient subgroup)

1 evidences

Cluster-randomized trial of daily zinc (10 mg), iron–folic acid, combination, or placebo in infants/toddlers over ~1 year found no overall effect of zinc on temperament or eating behaviors, except improved eating behavior among children with baseline iron-deficiency anemia.

Trust comment: Large cluster-randomized, double-masked trial with good retention and appropriate analyses; outcomes are caregiver-reported which is a limitation.

Study Details

PMID:25821959
Participants:569
Impact:Improved with zinc (adjusted β = −0.3; 95% CI −0.6, −0.01)
Trust score:4/5

IGF1 concentration

1 evidences

Substudy of a randomized trial comparing daily preventive zinc, MNP (including zinc), and placebo for 36 weeks in young children found no overall effect of zinc on IGF1 or IGFBP3, though baseline biomarker levels modified growth responses to preventive zinc in some subgroups.

Trust comment: Well-powered randomized controlled trial with prespecified analysis plan and biomarker assays; subgroup/modifier results require cautious interpretation.

Study Details

PMID:37299552
Participants:408
Impact:No main effect at endline (geometric mean ~39 ng/mL; P=0.99)
Trust score:4/5

IGFBP3 concentration

1 evidences

Substudy of a randomized trial comparing daily preventive zinc, MNP (including zinc), and placebo for 36 weeks in young children found no overall effect of zinc on IGF1 or IGFBP3, though baseline biomarker levels modified growth responses to preventive zinc in some subgroups.

Trust comment: Well-powered randomized controlled trial with prespecified analysis plan and biomarker assays; subgroup/modifier results require cautious interpretation.

Study Details

PMID:37299552
Participants:408
Impact:No main effect at endline (mean ~2038–2075 ng/mL; P=0.83)
Trust score:4/5

growth response modified by baseline biomarkers

1 evidences

Substudy of a randomized trial comparing daily preventive zinc, MNP (including zinc), and placebo for 36 weeks in young children found no overall effect of zinc on IGF1 or IGFBP3, though baseline biomarker levels modified growth responses to preventive zinc in some subgroups.

Trust comment: Well-powered randomized controlled trial with prespecified analysis plan and biomarker assays; subgroup/modifier results require cautious interpretation.

Study Details

PMID:37299552
Participants:408
Impact:Preventive zinc improved LAZ at 18 weeks in highest baseline IGF1 tertile and improved WAZ at 36 weeks in lowest baseline IGFBP3 tertile (interaction P<0.1)
Trust score:4/5

renal metallothionein expression (in vitro)

1 evidences

Mixed in vitro and small in vivo study: zinc induced metallothionein (MTT) expression dose-dependently in renal cell cultures; short-term oral zinc (60 mg/day for 2 days) did not significantly raise serum MTT in patients with impaired kidney function though Zn altered the MTT–eGFR relationship.

Trust comment: Strong in vitro data; small human sample (n=54) with short Zn exposure limits the strength of in vivo conclusions for humans.

Study Details

PMID:28302075
Participants:54
Impact:Dose-dependent increase in MTT mRNA/protein with rising Zn concentrations (statistically significant, p<0.0001)
Trust score:3/5

serum metallothionein (in vivo)

1 evidences

Mixed in vitro and small in vivo study: zinc induced metallothionein (MTT) expression dose-dependently in renal cell cultures; short-term oral zinc (60 mg/day for 2 days) did not significantly raise serum MTT in patients with impaired kidney function though Zn altered the MTT–eGFR relationship.

Trust comment: Strong in vitro data; small human sample (n=54) with short Zn exposure limits the strength of in vivo conclusions for humans.

Study Details

PMID:28302075
Participants:54
Impact:No significant change after 2 days of 60 mg/day Zn in patients (no group difference; p>0.05)
Trust score:3/5

MTT–eGFR correlation under Zn

1 evidences

Mixed in vitro and small in vivo study: zinc induced metallothionein (MTT) expression dose-dependently in renal cell cultures; short-term oral zinc (60 mg/day for 2 days) did not significantly raise serum MTT in patients with impaired kidney function though Zn altered the MTT–eGFR relationship.

Trust comment: Strong in vitro data; small human sample (n=54) with short Zn exposure limits the strength of in vivo conclusions for humans.

Study Details

PMID:28302075
Participants:54
Impact:Negative correlation rho = −0.49 (p = 0.04) with Zn influencing this relationship (interaction p = 0.01)
Trust score:3/5

blood Cu/Zn ratio

1 evidences

Children with ASD (52) and controls (22) were compared for blood metals and urinary porphyrins; ASD group had higher blood Cu/Zn ratio and lower coproporphyrins.

Trust comment: Moderate-quality cross-sectional clinical study with clear methods and moderate sample size, but observational design limits causal inference.

Study Details

PMID:25234471
Participants:74
Impact:elevated in ASD vs controls (significant, p=0.010)
Trust score:3/5

blood zinc (Zn) level

1 evidences

Children with ASD (52) and controls (22) were compared for blood metals and urinary porphyrins; ASD group had higher blood Cu/Zn ratio and lower coproporphyrins.

Trust comment: Moderate-quality cross-sectional clinical study with clear methods and moderate sample size, but observational design limits causal inference.

Study Details

PMID:25234471
Participants:74
Impact:no significant difference between ASD and controls
Trust score:3/5

urinary coproporphyrin I/III

1 evidences

Children with ASD (52) and controls (22) were compared for blood metals and urinary porphyrins; ASD group had higher blood Cu/Zn ratio and lower coproporphyrins.

Trust comment: Moderate-quality cross-sectional clinical study with clear methods and moderate sample size, but observational design limits causal inference.

Study Details

PMID:25234471
Participants:74
Impact:lower in ASD vs controls (significant)
Trust score:3/5

recovery within 5 days

1 evidences

Double-blind RCT in 80 malnourished children: zinc syrup shortened diarrhoea, reduced stool output and ORS use and improved early recovery rates.

Trust comment: Double-blind RCT with clear positive clinical effects and appropriate statistics, though sample size is modest.

Study Details

PMID:11077932
Participants:80
Impact:100% (zinc) vs 89% (placebo), p=0.04
Trust score:4/5

stool output (liquid)

1 evidences

Double-blind RCT in 80 malnourished children: zinc syrup shortened diarrhoea, reduced stool output and ORS use and improved early recovery rates.

Trust comment: Double-blind RCT with clear positive clinical effects and appropriate statistics, though sample size is modest.

Study Details

PMID:11077932
Participants:80
Impact:1.5±0.7 kg (zinc) vs 2.4±0.7 kg (placebo); ~0.9 kg less (p=0.0001)
Trust score:4/5

height / height-for-age z-score

1 evidences

Randomized trial in 290 preschoolers: vitamin A + zinc improved height gains; multiple micronutrients yielded greater hemoglobin increases; serum zinc rose most in the vitamin A+zinc group.

Trust comment: Well-sized randomized trial with multiple arms and biologic endpoints, though full methodological details (blinding etc.) are limited in the summary.

Study Details

PMID:22374555
Participants:290
Impact:greater gains in vitamin A + zinc group vs other groups (significant)
Trust score:4/5

HCMV-IgM negative conversion rate

1 evidences

Randomized study of 140 HCMV-IgM positive patients: combining zinc (gluconate) with herbal Jinye Baidu granule increased HCMV-IgM negative conversion at moderate (20 mg) and high (30 mg) zinc doses.

Trust comment: Randomized clinical trial with reasonable sample size but limited reporting on blinding, outcome details, and potential bias.

Study Details

PMID:15957842
Participants:140
Impact:higher with zinc + JBG at 20 mg and 30 mg vs JBG alone (significant); 10 mg not significant
Trust score:3/5

serum lipids / copper

1 evidences

Substudy of AREDS (717 participants): 5 years of zinc oxide supplementation increased serum zinc (~17% median) versus ~2% in non-zinc groups, with no significant long-term effects on hematocrit, copper, or lipids.

Trust comment: High-quality long-term randomized trial substudy with clear objective biomarker outcomes and large sample for this analysis.

Study Details

PMID:11925463
Participants:717
Impact:no significant difference after 5 years
Trust score:5/5

ADAS-cog (cognitive score)

1 evidences

Pilot randomized trial of clioquinol (a metal-protein-attenuating compound) in Alzheimer patients: treatment was associated with reduced plasma Abeta42, raised plasma zinc, and less cognitive worsening in a more severely affected subgroup.

Trust comment: Small pilot randomized trial showing biologic effects, but limited size and exploratory endpoints reduce confidence.

Study Details

PMID:14676042
Participants:36
Impact:less deterioration in treated vs placebo in more severely affected subgroup (reported as significant)
Trust score:3/5

plasma Abeta42

1 evidences

Pilot randomized trial of clioquinol (a metal-protein-attenuating compound) in Alzheimer patients: treatment was associated with reduced plasma Abeta42, raised plasma zinc, and less cognitive worsening in a more severely affected subgroup.

Trust comment: Small pilot randomized trial showing biologic effects, but limited size and exploratory endpoints reduce confidence.

Study Details

PMID:14676042
Participants:36
Impact:decreased in clioquinol group vs increased in placebo
Trust score:3/5

gingival severity

1 evidences

Randomized double-blind trial (92 completers) found the amine+zinc+lactate+fluoride toothpaste significantly reduced gingivitis and plaque versus a fluoride-only control at 3 and 6 months.

Trust comment: Randomized, double-blind single-site trial with appropriate endpoints and statistics, though single-site limits generalizability.

Study Details

PMID:39910536
Participants:92
Impact:baseline-adjusted improvement vs control: 42.2% at 6 months (p<0.001)
Trust score:4/5

protein intake

2 evidences

A 4-month RCT sending weekly SMS to caregivers increased some infant nutrient intakes; infants in the SMS feeding-practices group had higher protein, calcium, zinc and grain intake at 4–6 months.

Trust comment: Randomized multi-site trial with validated FFQ and significant differences, but short duration and self-reported diet limit generalizability.

Study Details

PMID:36249246
Participants:163
Impact:+2.45 g median (13.5 vs 11.05 g; intervention vs control) at 4–6 months
Trust score:4/5

Supplementing underweight infants with LNS or CSB increased nutrient intakes; LNS increased total energy and protein more than control.

Trust comment: Large randomized trial substudy with objective dietary assessment, though supplement compositions differ and effects are on intake rather than clinical outcomes.

Study Details

PMID:24528807
Participants:188
Impact:+46 (units reported; 95% CI 1.5–7.6; P<0.001)
Trust score:4/5

calcium intake

1 evidences

A 4-month RCT sending weekly SMS to caregivers increased some infant nutrient intakes; infants in the SMS feeding-practices group had higher protein, calcium, zinc and grain intake at 4–6 months.

Trust comment: Randomized multi-site trial with validated FFQ and significant differences, but short duration and self-reported diet limit generalizability.

Study Details

PMID:36249246
Participants:163
Impact:+43 mg median (472 vs 429 mg; intervention vs control) at 4–6 months
Trust score:4/5

total grains intake

1 evidences

A 4-month RCT sending weekly SMS to caregivers increased some infant nutrient intakes; infants in the SMS feeding-practices group had higher protein, calcium, zinc and grain intake at 4–6 months.

Trust comment: Randomized multi-site trial with validated FFQ and significant differences, but short duration and self-reported diet limit generalizability.

Study Details

PMID:36249246
Participants:163
Impact:+0.12 oz median (0.28 vs 0.16 oz; intervention vs control) at 4–6 months
Trust score:4/5

loading-dose benefit

1 evidences

Two zinc gluconate dosing regimens (with or without loading dose) showed no difference in inflammatory lesion outcomes over 3 months.

Trust comment: Double-blind clinical trial but small sample and comparison was between two zinc regimens (no placebo control reported here).

Study Details

PMID:10846252
Participants:67
Impact:No additional benefit from loading-dose regimen
Trust score:3/5

gustatory (taste) sensitivity

1 evidences

Oral polaprezinc (zinc) at 68 mg/day improved taste sensitivity in patients with idiopathic taste disorders versus placebo.

Trust comment: GCP-compliant randomized, double-blind, placebo-controlled multi-center trial with dose-response finding and tolerable safety profile.

Study Details

PMID:19037756
Participants:109
Impact:Significant improvement with 68 mg zinc vs placebo over 12 weeks
Trust score:5/5

clinical success rate (≥2/3 lesion reduction)

1 evidences

Zinc gluconate was effective for inflammatory acne but was less effective than minocycline over 3 months.

Trust comment: Large multicenter randomized double-blind trial with clear clinical endpoints showing zinc is effective but inferior to minocycline.

Study Details

PMID:11586012
Participants:332
Impact:31.2% for zinc vs 63.4% for minocycline at day 90
Trust score:5/5

relative efficacy

1 evidences

Zinc gluconate was effective for inflammatory acne but was less effective than minocycline over 3 months.

Trust comment: Large multicenter randomized double-blind trial with clear clinical endpoints showing zinc is effective but inferior to minocycline.

Study Details

PMID:11586012
Participants:332
Impact:Zinc showed ~17% lower effect than minocycline (mean lesion count change)
Trust score:5/5

progression to type 2 diabetes

1 evidences

In adults with prediabetes, 20 mg/day zinc reduced progression to type 2 diabetes and improved glycemic and some lipid measures over 12 months.

Trust comment: Randomized, double-blind, placebo-controlled trial (n=200) with clear endpoints and statistically significant results.

Study Details

PMID:29072815
Participants:200
Impact:-14 percentage points (25.0% control to 11.0% zinc; P=0.016)
Trust score:5/5

total cholesterol and LDL-C

1 evidences

In adults with prediabetes, 20 mg/day zinc reduced progression to type 2 diabetes and improved glycemic and some lipid measures over 12 months.

Trust comment: Randomized, double-blind, placebo-controlled trial (n=200) with clear endpoints and statistically significant results.

Study Details

PMID:29072815
Participants:200
Impact:decreased (significant)
Trust score:5/5

incidence of acute respiratory infection

1 evidences

In preschool children, zinc amino acid chelate reduced respiratory infection incidence compared with placebo; effects on diarrhea were directionally lower but not statistically significant.

Trust comment: Randomized, triple-blind community trial with n=301 and significant result for respiratory infections for one zinc formulation, though some outcomes were non-significant.

Study Details

PMID:24967861
Participants:301
Impact:-57% (1.42 vs 3.3 per 1,000 child-days; RR=0.43; 95% CI: 0.196–0.950; P=0.049) for zinc amino acid chelate vs placebo
Trust score:4/5

incidence of acute diarrhea

1 evidences

In preschool children, zinc amino acid chelate reduced respiratory infection incidence compared with placebo; effects on diarrhea were directionally lower but not statistically significant.

Trust comment: Randomized, triple-blind community trial with n=301 and significant result for respiratory infections for one zinc formulation, though some outcomes were non-significant.

Study Details

PMID:24967861
Participants:301
Impact:decreased (non-significant; lower rates with chelate vs placebo but P>0.3)
Trust score:4/5

time to recovery from severe or very severe pneumonia

1 evidences

In hospitalized young children with severe pneumonia, adjunctive zinc did not shorten recovery time overall; a benefit was suggested in a very severe subgroup but was not robust after adjustment.

Trust comment: Large randomized, double-blind, placebo-controlled trial (n=550) with clear primary outcome though subgroup findings were sensitive to adjustment.

Study Details

PMID:23636236
Participants:550
Impact:no overall effect (HR 0.98; 95% CI: 0.82–1.17); possible faster recovery in very severe subgroup (HR 1.52; 95% CI: 1.03–2.23) but not robust after adjustment
Trust score:4/5

anti-E. coli plasma IgG level

1 evidences

In young Laotian children, daily preventive zinc (and some zinc regimens) increased anti-E. coli IgG levels, and preventive zinc improved antibody avidity in zinc-deficient children.

Trust comment: Randomized controlled parent trial with a well-described immunology sub-study (200 samples); subgroup effects in zinc-deficient children are plausible though based on a subset.

Study Details

PMID:36167891
Participants:200
Impact:increased (significant from baseline in TZ and PZ groups; proportion with ≥10% increase higher vs control)
Trust score:4/5

antibody avidity index (anti-E. coli)

1 evidences

In young Laotian children, daily preventive zinc (and some zinc regimens) increased anti-E. coli IgG levels, and preventive zinc improved antibody avidity in zinc-deficient children.

Trust comment: Randomized controlled parent trial with a well-described immunology sub-study (200 samples); subgroup effects in zinc-deficient children are plausible though based on a subset.

Study Details

PMID:36167891
Participants:200
Impact:increased in PZ group (significant in zinc-deficient children)
Trust score:4/5

incidence of postoperative sore throat (POST)

1 evidences

Single 40 mg zinc lozenge given 30 minutes before intubation reduced early postoperative sore throat incidence and lowered mild/moderate severity.

Trust comment: Well-designed randomized double-blind placebo-controlled trial but moderate sample size (n=79).

Study Details

PMID:28953493
Participants:79
Impact:−22 percentage points (7% vs 29% at 4 h)
Trust score:4/5

incidence of POST at 0 and 2 hours

1 evidences

Single 40 mg zinc lozenge given 30 minutes before intubation reduced early postoperative sore throat incidence and lowered mild/moderate severity.

Trust comment: Well-designed randomized double-blind placebo-controlled trial but moderate sample size (n=79).

Study Details

PMID:28953493
Participants:79
Impact:0% vs 24% at 0 h; 10% vs 34% at 2 h (zinc vs control)
Trust score:4/5

severity of POST (mild and moderate)

1 evidences

Single 40 mg zinc lozenge given 30 minutes before intubation reduced early postoperative sore throat incidence and lowered mild/moderate severity.

Trust comment: Well-designed randomized double-blind placebo-controlled trial but moderate sample size (n=79).

Study Details

PMID:28953493
Participants:79
Impact:decreased (statistically significant, P≤0.004)
Trust score:4/5

nosocomial infection incidence

1 evidences

Children given a mixture (Lactobacillus GG + vitamins B/C + zinc) had fewer nosocomial infections, less diarrhoea, and shorter hospital stays than placebo.

Trust comment: Randomized trial but intervention was a multi-component mixture (including zinc), so effects cannot be attributed to zinc alone.

Study Details

PMID:27464469
Participants:90
Impact:−24 percentage points (9% vs 33%)
Trust score:3/5

hospitalisation duration

1 evidences

Children given a mixture (Lactobacillus GG + vitamins B/C + zinc) had fewer nosocomial infections, less diarrhoea, and shorter hospital stays than placebo.

Trust comment: Randomized trial but intervention was a multi-component mixture (including zinc), so effects cannot be attributed to zinc alone.

Study Details

PMID:27464469
Participants:90
Impact:−1.0 day (3.9 vs 4.9 days; P = 0.003)
Trust score:3/5

weight gain and stool weight

1 evidences

An infant formula containing probiotics, prebiotics, fiber and increased zinc+iron shortened duration of acute diarrhea versus control formula.

Trust comment: Randomized trial but multifactorial formula (zinc included among other active ingredients) so individual zinc contribution is unclear.

Study Details

PMID:17704024
Participants:58
Impact:no significant change
Trust score:3/5

progression to late age-related macular degeneration (AMD)

1 evidences

In long-term follow-up of AREDS2 participants, low versus high zinc doses showed no significant effect on progression to late AMD.

Trust comment: Large multicenter randomized trial cohort with long-term follow-up and validated outcomes; zinc dose comparison showed null effect.

Study Details

PMID:35653117
Participants:3882
Impact:no significant effect (HR 1.04; 95% CI 0.94–1.14; P = 0.49)
Trust score:5/5

glutathione peroxidase (GPx) activity

1 evidences

Eight weeks of zinc supplementation in postmenopausal women improved erythrocyte zinc status and was associated with enhanced antioxidant markers.

Trust comment: Double-blind randomized design supports causality but sample size is small and outcomes are biomarker/correlational.

Study Details

PMID:35278643
Participants:51
Impact:positively correlated with erythrocyte Zn after intervention (r = 0.61; p < 0.01)
Trust score:4/5

health-related quality of life (HRQoL)

1 evidences

Long-term daily supplementation with a capsule containing vitamins and minerals (including 20 mg zinc) did not improve health-related quality of life versus placebo.

Trust comment: Large randomized, double-blind, placebo-controlled primary prevention trial with long follow-up, though zinc was part of a combined supplement.

Study Details

PMID:22158670
Participants:8112
Impact:no significant effect over ~76 months (no differences vs placebo)
Trust score:5/5

executive function / working memory / inhibition

1 evidences

Follow-up of infants given multiple micronutrients (including zinc) vs iron alone found no long-term benefits on preschool cognitive, executive function or behavioural outcomes.

Trust comment: Randomized original trial with blinded follow-up but MMN product contained multiple nutrients (including zinc) and follow-up sample was a subset (n=182), limiting attribution to zinc alone.

Study Details

PMID:26262642
Participants:182
Impact:no significant long-term effect (MMN vs iron)
Trust score:4/5

intelligence (WPPSI IQ scores)

1 evidences

Follow-up of infants given multiple micronutrients (including zinc) vs iron alone found no long-term benefits on preschool cognitive, executive function or behavioural outcomes.

Trust comment: Randomized original trial with blinded follow-up but MMN product contained multiple nutrients (including zinc) and follow-up sample was a subset (n=182), limiting attribution to zinc alone.

Study Details

PMID:26262642
Participants:182
Impact:no significant long-term effect (total IQ similar between groups)
Trust score:4/5

behaviour / social-emotional scores (BITSEA)

1 evidences

Follow-up of infants given multiple micronutrients (including zinc) vs iron alone found no long-term benefits on preschool cognitive, executive function or behavioural outcomes.

Trust comment: Randomized original trial with blinded follow-up but MMN product contained multiple nutrients (including zinc) and follow-up sample was a subset (n=182), limiting attribution to zinc alone.

Study Details

PMID:26262642
Participants:182
Impact:no significant long-term effect
Trust score:4/5

linear growth (length gain)

1 evidences

Daily micronutrient powder containing zinc modestly increased growth and reduced iron-deficiency anaemia but was associated with more diarrhoea in young children.

Trust comment: Large, cluster-randomized, masked trial with clinical endpoints and registry entry; multi-micronutrient formulation complicates zinc-specific attribution.

Study Details

PMID:23602230
Participants:2746
Impact:+0.56 cm (6–18 months vs control)
Trust score:4/5

iron-deficiency anaemia

1 evidences

Daily micronutrient powder containing zinc modestly increased growth and reduced iron-deficiency anaemia but was associated with more diarrhoea in young children.

Trust comment: Large, cluster-randomized, masked trial with clinical endpoints and registry entry; multi-micronutrient formulation complicates zinc-specific attribution.

Study Details

PMID:23602230
Participants:2746
Impact:reduced odds (OR 0.25 at 18 months)
Trust score:4/5

diarrhoea burden

1 evidences

Daily micronutrient powder containing zinc modestly increased growth and reduced iron-deficiency anaemia but was associated with more diarrhoea in young children.

Trust comment: Large, cluster-randomized, masked trial with clinical endpoints and registry entry; multi-micronutrient formulation complicates zinc-specific attribution.

Study Details

PMID:23602230
Participants:2746
Impact:increased proportion of days with diarrhoea and increased bloody diarrhoea (p=0.001 and p=0.003)
Trust score:4/5

hs-CRP

4 evidences

Ten weeks of combined zinc, vitamin A, and magnesium supplementation increased FT4 and lowered hs-CRP compared with placebo in hypothyroid patients.

Trust comment: Randomized trial but small sample and co-supplementation prevents isolating effects attributable to zinc alone.

Study Details

PMID:33409923
Participants:86
Impact:decreased in intervention group (P<0.05) vs increase in placebo
Trust score:3/5

Twelve weeks of magnesium-zinc-calcium-vitamin D co-supplementation in women with PCOS reduced hirsutism and some inflammation/oxidative stress markers and increased antioxidant capacity.

Trust comment: Randomized double-blind placebo-controlled trial with clear biomarker changes, but co-supplementation prevents attribution of effects solely to zinc.

Study Details

PMID:28668998
Participants:60
Impact:-0.7 ± 0.8 mg/L vs +0.2 ± 1.8 mg/L (change)
Trust score:4/5

In women with gestational diabetes, 6 weeks of zinc (30 mg/day) increased serum zinc and antioxidant capacity and lowered hs-CRP, without changing pregnancy outcomes.

Trust comment: Randomized, double-blind, placebo-controlled trial but small sample (n=50) limits precision.

Study Details

PMID:26465829
Participants:50
Impact:decrease (mean change −110.1 ng/mL vs +1137.8 ng/mL in placebo; P=0.03)
Trust score:4/5

In pregnant women at risk for IUGR, 30 mg/day zinc for 10 weeks reduced inflammation and oxidative stress markers and lowered insulin; no effect on uterine artery PI.

Trust comment: Randomized double-blind placebo-controlled trial with biomarker endpoints but small sample (n=52) limits generalizability.

Study Details

PMID:31248307
Participants:52
Impact:-1.17 mg/L (β)
Trust score:4/5

motor nerve conduction velocity (peripheral neuropathy)

1 evidences

Six weeks of oral zinc in patients with diabetic neuropathy improved glycemic control and peripheral nerve conduction compared with placebo.

Trust comment: Small randomized double-blind study with limited reporting and few participants (15 treated, 15 placebo), reducing confidence in effect estimates.

Study Details

PMID:11229219
Participants:30
Impact:improved (study reports improvement vs placebo)
Trust score:3/5

glycemic control (FBS/PPBS)

1 evidences

Six weeks of oral zinc in patients with diabetic neuropathy improved glycemic control and peripheral nerve conduction compared with placebo.

Trust comment: Small randomized double-blind study with limited reporting and few participants (15 treated, 15 placebo), reducing confidence in effect estimates.

Study Details

PMID:11229219
Participants:30
Impact:improved (reported better glycemic control with zinc)
Trust score:3/5

whole-body bone density and T score

1 evidences

Among 224 postmenopausal women given vitamin D and calcium, whole-body bone density and T-scores decreased over 2 years; zinc supplementation effects depended on baseline zinc intake.

Trust comment: Well-designed double-blind randomized supplementation trial over 2 years with meaningful sample size; subgroup effects by baseline intake require cautious interpretation.

Study Details

PMID:21733304
Participants:224
Impact:prevention of significant decrease with Zn supplementation in women with baseline Zn intake <8.0 mg/d (protective effect)
Trust score:4/5

lipid peroxidation

1 evidences

50 mg zinc daily for 8 weeks lowered oxidative stress markers and increased antioxidant capacity in overweight patients with type 2 diabetes.

Trust comment: Randomised double-blind placebo-controlled trial (n=70) reporting statistically significant changes in oxidative markers, but small sample size limits generalisability.

Study Details

PMID:37137539
Participants:70
Impact:-25%
Trust score:4/5

total oxidant status

1 evidences

50 mg zinc daily for 8 weeks lowered oxidative stress markers and increased antioxidant capacity in overweight patients with type 2 diabetes.

Trust comment: Randomised double-blind placebo-controlled trial (n=70) reporting statistically significant changes in oxidative markers, but small sample size limits generalisability.

Study Details

PMID:37137539
Participants:70
Impact:-25%
Trust score:4/5

total antioxidant capacity

1 evidences

50 mg zinc daily for 8 weeks lowered oxidative stress markers and increased antioxidant capacity in overweight patients with type 2 diabetes.

Trust comment: Randomised double-blind placebo-controlled trial (n=70) reporting statistically significant changes in oxidative markers, but small sample size limits generalisability.

Study Details

PMID:37137539
Participants:70
Impact:+16%
Trust score:4/5

coronary artery disease (odds)

1 evidences

Matched case-control study in Nepalese men found an inverse association between dietary calcium intake and coronary artery disease by G-estimation, but results were inconsistent across analytic methods.

Trust comment: Well-sized matched case-control with causal-analytic methods but observational design limits causal inference and residual confounding is possible.

Study Details

PMID:33745624
Participants:466
Impact:-9% odds (G-estimation, OR 0.91); -27% odds (IPTW, OR 0.73)
Trust score:3/5

total cancer incidence (men)

2 evidences

Large randomized trial of daily low-dose antioxidant supplement (included 20 mg Zn) showed lower total cancer incidence in men but not in women after 7.5 years.

Trust comment: Large, long-duration randomized trial with robust sample size but zinc was given as part of a multi-nutrient supplement so effects cannot be attributed to zinc alone.

Study Details

PMID:16115341
Participants:12741
Impact:decreased (after 7.5 years)
Trust score:4/5

Long-term low-dose antioxidant/multi-mineral supplementation (including 20 mg zinc) reduced total cancer incidence and all-cause mortality in men but not in women over ~7.5 years.

Trust comment: Large, long-term randomized placebo-controlled trial with robust outcomes, but supplement was a multi-nutrient formulation so effects cannot be attributed to zinc alone.

Study Details

PMID:15557412
Participants:13017
Impact:-31% (RR 0.69)
Trust score:4/5

all-cause mortality (men)

1 evidences

Long-term low-dose antioxidant/multi-mineral supplementation (including 20 mg zinc) reduced total cancer incidence and all-cause mortality in men but not in women over ~7.5 years.

Trust comment: Large, long-term randomized placebo-controlled trial with robust outcomes, but supplement was a multi-nutrient formulation so effects cannot be attributed to zinc alone.

Study Details

PMID:15557412
Participants:13017
Impact:-37% (RR 0.63)
Trust score:4/5

semen zinc concentration

1 evidences

Randomized clinical observation: Jingling oral liquid increased pregnancy rates and improved semen parameters including higher seminal zinc and SOD.

Trust comment: Randomized but single-center trial with limited detail on blinding and methods; outcomes clinically relevant but study quality unclear.

Study Details

PMID:15074089
Participants:60
Impact:increased (P<0.05)
Trust score:3/5

semen superoxide dismutase (SOD)

1 evidences

Randomized clinical observation: Jingling oral liquid increased pregnancy rates and improved semen parameters including higher seminal zinc and SOD.

Trust comment: Randomized but single-center trial with limited detail on blinding and methods; outcomes clinically relevant but study quality unclear.

Study Details

PMID:15074089
Participants:60
Impact:increased (P<0.05)
Trust score:3/5

rosacea severity

1 evidences

Double-blind RCT: oral zinc raised serum zinc but did not improve rosacea severity vs placebo over 90 days.

Trust comment: Randomized double-blind trial with objective scoring but modest sample size (n=44) limiting power to detect small effects.

Study Details

PMID:22435439
Participants:44
Impact:no significant difference vs placebo (P=0.284)
Trust score:4/5

hydrogen sulfide (H2S) in morning breath

1 evidences

Cross-over trial: zinc- and strontium-containing toothpastes/rinses markedly reduced morning volatile sulfur compounds compared with controls.

Trust comment: Randomized double-blind cross-over design is robust for acute effects though sample size moderate (n=30); objective GC measurements support validity.

Study Details

PMID:25689513
Participants:30
Impact:median reduction ~70% vs control
Trust score:4/5

methyl mercaptan (CH3SH) in morning breath

1 evidences

Cross-over trial: zinc- and strontium-containing toothpastes/rinses markedly reduced morning volatile sulfur compounds compared with controls.

Trust comment: Randomized double-blind cross-over design is robust for acute effects though sample size moderate (n=30); objective GC measurements support validity.

Study Details

PMID:25689513
Participants:30
Impact:median reduction 55–57% vs control
Trust score:4/5

salivary zinc

1 evidences

Cross-over trial: zinc- and strontium-containing toothpastes/rinses markedly reduced morning volatile sulfur compounds compared with controls.

Trust comment: Randomized double-blind cross-over design is robust for acute effects though sample size moderate (n=30); objective GC measurements support validity.

Study Details

PMID:25689513
Participants:30
Impact:higher after zinc-containing rinse vs zinc toothpaste
Trust score:4/5

AMD progression response to zinc-containing AREDS supplements

1 evidences

Pharmacogenetic analysis of AREDS: CFH genotype influenced response to AREDS supplements containing zinc, with a significant interaction observed.

Trust comment: Large retrospective pharmacogenetic analysis of randomized trial data with biologically plausible findings, but requires independent replication before clinical change.

Study Details

PMID:18423869
Participants:876
Impact:treatment response varied by CFH genotype (interaction P=0.004; CFH Y402H interaction P=0.03)
Trust score:4/5

anaemia prevalence (Hb<10 g/dL)

1 evidences

Cluster-randomized trial in 6–24 month children comparing rice-based fortified complementary food, sprinkle powder (both containing iron+zinc), or education only for 6 months; fortified complementary food increased haemoglobin and reduced anemia but did not affect linear growth.

Trust comment: Cluster-randomized study with 292 children and objective hematologic endpoints, but zinc was given together with iron so effects specific to zinc cannot be isolated.

Study Details

PMID:25076659
Participants:292
Impact:−67% (fortified complementary food group) vs −27% (sprinkle) and −22% (control)
Trust score:4/5

linear growth (length/weight velocity)

1 evidences

Cluster-randomized trial in 6–24 month children comparing rice-based fortified complementary food, sprinkle powder (both containing iron+zinc), or education only for 6 months; fortified complementary food increased haemoglobin and reduced anemia but did not affect linear growth.

Trust comment: Cluster-randomized study with 292 children and objective hematologic endpoints, but zinc was given together with iron so effects specific to zinc cannot be isolated.

Study Details

PMID:25076659
Participants:292
Impact:no significant change
Trust score:4/5

radial bone mineral content

1 evidences

Preterm infants fed a nutrient-enriched formula (higher protein, Ca, P, and zinc) had greater linear growth, bone mineral content, and lean mass by 3 months corrected age compared with standard formula.

Trust comment: Blinded randomized nutrition trial with objective body-composition outcomes but multinutrient enrichment (not zinc alone) limits attribution solely to zinc.

Study Details

PMID:9738713
Participants:60
Impact:increased (P<0.01)
Trust score:4/5

lean mass

1 evidences

Preterm infants fed a nutrient-enriched formula (higher protein, Ca, P, and zinc) had greater linear growth, bone mineral content, and lean mass by 3 months corrected age compared with standard formula.

Trust comment: Blinded randomized nutrition trial with objective body-composition outcomes but multinutrient enrichment (not zinc alone) limits attribution solely to zinc.

Study Details

PMID:9738713
Participants:60
Impact:increased (P<0.01)
Trust score:4/5

EED biomarkers (anti-flagellin / anti-LPS IgA & IgG)

1 evidences

Subanalysis of a large double-blind RCT in Tanzanian infants showed that daily preventive zinc (and/or multivitamins) did not reduce EED or systemic inflammation biomarkers at 6 months.

Trust comment: Large, double-blind, placebo-controlled randomized trial subanalysis with high-quality laboratory assays and excellent compliance; effects largely null for zinc.

Study Details

PMID:30952509
Participants:590
Impact:no significant change with zinc
Trust score:5/5

systemic inflammation (CRP, AGP)

1 evidences

Subanalysis of a large double-blind RCT in Tanzanian infants showed that daily preventive zinc (and/or multivitamins) did not reduce EED or systemic inflammation biomarkers at 6 months.

Trust comment: Large, double-blind, placebo-controlled randomized trial subanalysis with high-quality laboratory assays and excellent compliance; effects largely null for zinc.

Study Details

PMID:30952509
Participants:590
Impact:no significant change with zinc
Trust score:5/5

IGFBP-3

1 evidences

Subanalysis of a large double-blind RCT in Tanzanian infants showed that daily preventive zinc (and/or multivitamins) did not reduce EED or systemic inflammation biomarkers at 6 months.

Trust comment: Large, double-blind, placebo-controlled randomized trial subanalysis with high-quality laboratory assays and excellent compliance; effects largely null for zinc.

Study Details

PMID:30952509
Participants:590
Impact:lower at 6 months with zinc (~981 vs 1019 ng/mL; P=0.03) and smaller change from 6 wk to 6 mo (P=0.02)
Trust score:5/5

zinc status / homeostasis

1 evidences

A low-sodium diet in pregnancy reduced magnesium intake but maternal magnesium homeostasis was maintained via reduced urinary excretion.

Trust comment: Randomized dietary intervention with measured nutrient excretion showing maintained zinc homeostasis, but small sample and indirect focus on zinc reduce strength of inference.

Study Details

PMID:9175991
Participants:94
Impact:maintained (no significant change despite lower intake)
Trust score:3/5

sustained recovery (12 months)

1 evidences

Adding a package (including zinc) to standard care did not significantly increase sustained recovery from moderate acute malnutrition over 12 months.

Trust comment: Large cluster-randomized trial with good follow-up, but zinc was given as part of a multi-component package so zinc-specific effects cannot be isolated.

Study Details

PMID:28615258
Participants:1383
Impact:+3 percentage points (56% vs 53%); no significant difference (P=0.38)
Trust score:4/5

PUSH score (pressure ulcer healing)

1 evidences

A protein/arginine/zinc/vitamin C–enriched oral supplement accelerated pressure ulcer healing versus standard nutrition over 12 weeks, but zinc was not tested alone.

Trust comment: Randomized trial but small sample and multi-nutrient intervention prevents attribution of effects specifically to zinc.

Study Details

PMID:19563522
Participants:28
Impact:treatment change -6.1 vs control -3.3 at Week 12 (greater improvement; P<0.05)
Trust score:3/5

ulcer surface area reduction

1 evidences

A protein/arginine/zinc/vitamin C–enriched oral supplement accelerated pressure ulcer healing versus standard nutrition over 12 weeks, but zinc was not tested alone.

Trust comment: Randomized trial but small sample and multi-nutrient intervention prevents attribution of effects specifically to zinc.

Study Details

PMID:19563522
Participants:28
Impact:-1,140.9 mm² vs -571.7 mm² (~57% vs ~33%) by Week 8; significant (P<0.05)
Trust score:3/5

salivary low-molecular-weight amines

1 evidences

In patients with halitosis, treatments including zinc tablets significantly lowered salivary amine levels, but levels began to rise again by 3 months; zinc was one of several interventions.

Trust comment: Includes randomized treatment arms but multiple interventions (zinc, chlorhexidine, probiotics) mean zinc-specific effects are unclear.

Study Details

PMID:15752096
Participants:124
Impact:significant reduction after treatment (P<0.001); partial rebound by 3 months
Trust score:3/5

iron and selenium status / iron deficiency

1 evidences

Fortified porridge improved anemia, iron and selenium status in Zambian infants but did not significantly raise overall serum zinc.

Trust comment: Large double-blind randomized trial (n=743) with objective biochemical endpoints; limited efficacy on overall zinc status.

Study Details

PMID:21411608
Participants:743
Impact:improved; reduced iron deficiency and anemia (reduced odds ratios vs basal)
Trust score:4/5

hyperactivity and impulsivity symptoms

1 evidences

Zinc sulfate was associated with reduced hyperactivity, impulsivity and impaired socialization symptoms in children with ADHD, but did not improve attention symptoms; overall response rates were modest.

Trust comment: Large double-blind randomized trial (n=400) with standard clinical scales; effect sizes were modest and response rates limited.

Study Details

PMID:14687872
Participants:400
Impact:statistically significant reduction vs placebo
Trust score:4/5

attention-deficit symptoms

1 evidences

Zinc sulfate was associated with reduced hyperactivity, impulsivity and impaired socialization symptoms in children with ADHD, but did not improve attention symptoms; overall response rates were modest.

Trust comment: Large double-blind randomized trial (n=400) with standard clinical scales; effect sizes were modest and response rates limited.

Study Details

PMID:14687872
Participants:400
Impact:no significant change
Trust score:4/5

full therapeutic response rate

1 evidences

Zinc sulfate was associated with reduced hyperactivity, impulsivity and impaired socialization symptoms in children with ADHD, but did not improve attention symptoms; overall response rates were modest.

Trust comment: Large double-blind randomized trial (n=400) with standard clinical scales; effect sizes were modest and response rates limited.

Study Details

PMID:14687872
Participants:400
Impact:28.7% (zinc) vs 20.0% (placebo), +8.7 percentage points
Trust score:4/5

total acne lesion count

1 evidences

Oral lactoferrin with vitamin E and zinc significantly reduced acne lesion counts versus placebo (maximum ~28.5% reduction) and improved sebum and both comedonal and inflammatory lesions.

Trust comment: Randomized double-blind placebo-controlled trial with 164 per-protocol completions and objective lesion counts; intervention combined lactoferrin, vitamin E and zinc.

Study Details

PMID:28369875
Participants:164
Impact:median percent reduction up to 28.5% (maximum at week 10; P<0.0001 vs placebo)
Trust score:4/5

inflammatory lesions

1 evidences

Oral lactoferrin with vitamin E and zinc significantly reduced acne lesion counts versus placebo (maximum ~28.5% reduction) and improved sebum and both comedonal and inflammatory lesions.

Trust comment: Randomized double-blind placebo-controlled trial with 164 per-protocol completions and objective lesion counts; intervention combined lactoferrin, vitamin E and zinc.

Study Details

PMID:28369875
Participants:164
Impact:maximum reduction 44% at week 10 (P<0.0001)
Trust score:4/5

comedones

1 evidences

Oral lactoferrin with vitamin E and zinc significantly reduced acne lesion counts versus placebo (maximum ~28.5% reduction) and improved sebum and both comedonal and inflammatory lesions.

Trust comment: Randomized double-blind placebo-controlled trial with 164 per-protocol completions and objective lesion counts; intervention combined lactoferrin, vitamin E and zinc.

Study Details

PMID:28369875
Participants:164
Impact:maximum reduction 32.5% at week 10 (P<0.0001)
Trust score:4/5

Hair zinc / taste acuity

1 evidences

A 4-month randomized trial in women with low iron stores tested dietary advice, iron supplement, or placebo and measured zinc status; iron supplements with meals appeared to lower zinc status.

Trust comment: Randomized, partially blinded placebo-controlled human trial with measured biomarkers; moderate risk from subgroup sizes but overall reliable.

Study Details

PMID:20416130
Participants:78
Impact:no change
Trust score:4/5

180-day survival

1 evidences

A randomized clinical trial compared combination therapy including zinc versus corticosteroids in severe alcohol-associated hepatitis and found similar survival at 180 days.

Trust comment: Randomized clinical trial but zinc was given as part of a multi-drug combination so zinc-specific effects cannot be isolated; sample modest for subgroup inference.

Study Details

PMID:35340032
Participants:103
Impact:COMB 67.9% vs PRED 56% (HR 0.69; p = 0.3001) — no significant difference
Trust score:3/5

28-day survival

1 evidences

A randomized clinical trial compared combination therapy including zinc versus corticosteroids in severe alcohol-associated hepatitis and found similar survival at 180 days.

Trust comment: Randomized clinical trial but zinc was given as part of a multi-drug combination so zinc-specific effects cannot be isolated; sample modest for subgroup inference.

Study Details

PMID:35340032
Participants:103
Impact:COMB 83.4% vs PRED 81.2% (HR 0.91; p = 0.85) — no significant difference
Trust score:3/5

infection rate / adverse events

1 evidences

A randomized clinical trial compared combination therapy including zinc versus corticosteroids in severe alcohol-associated hepatitis and found similar survival at 180 days.

Trust comment: Randomized clinical trial but zinc was given as part of a multi-drug combination so zinc-specific effects cannot be isolated; sample modest for subgroup inference.

Study Details

PMID:35340032
Participants:103
Impact:comparable between groups
Trust score:3/5

total T4 (TT4) vs red blood cell zinc

1 evidences

Cross-sectional baseline data from the ZENITH study showed no correlation between BMR and thyroid hormones but found a modest negative correlation between total T4 and red blood cell zinc.

Trust comment: Large multicentre observational dataset with appropriate biochemical assays but cross-sectional correlations limit causal inference.

Study Details

PMID:16254583
Participants:387
Impact:moderate negative correlation (r = -0.12; P < 0.02)
Trust score:3/5

iron status (hemoglobin, serum ferritin)

1 evidences

A randomized controlled trial in iron-depleted schoolchildren found that NaFeEDTA-fortified wheat improved iron status but did not change urinary zinc excretion after 7 months.

Trust comment: Randomized controlled trial with adequate sample and clear biomarker outcomes for urinary zinc and iron status.

Study Details

PMID:23156119
Participants:179
Impact:significantly improved in iron group (p < 0.001)
Trust score:4/5

placental zinc level

1 evidences

Nested case-control study found placental cadmium associated with higher odds of preeclampsia and reported interactions with placental selenium and zinc levels; placental zinc levels were higher in cases.

Trust comment: Well-characterized nested case-control with measured placental metals and adjusted models, though observational and limited by sample size for interactions.

Study Details

PMID:26422011
Participants:172
Impact:higher in preeclamptics (mean 8892.0 ng/g) vs controls (mean 8414.7 ng/g; p = 0.04)
Trust score:4/5

placental cadmium — odds of preeclampsia

1 evidences

Nested case-control study found placental cadmium associated with higher odds of preeclampsia and reported interactions with placental selenium and zinc levels; placental zinc levels were higher in cases.

Trust comment: Well-characterized nested case-control with measured placental metals and adjusted models, though observational and limited by sample size for interactions.

Study Details

PMID:26422011
Participants:172
Impact:increased odds (adjusted OR 1.5; 95% CI 1.1–2.2)
Trust score:4/5

Cd × Se interaction

1 evidences

Nested case-control study found placental cadmium associated with higher odds of preeclampsia and reported interactions with placental selenium and zinc levels; placental zinc levels were higher in cases.

Trust comment: Well-characterized nested case-control with measured placental metals and adjusted models, though observational and limited by sample size for interactions.

Study Details

PMID:26422011
Participants:172
Impact:low placental Se amplified Cd–preeclampsia association (OR 2.0; 95% CI 1.1–3.5)
Trust score:4/5

plasma ferritin concentration

1 evidences

One-year calcium supplementation in lactating Gambian women did not change urinary magnesium excretion or iron/zinc blood markers.

Trust comment: Randomized double-blind placebo-controlled trial with complete compliance and repeated measures; directly measured zinc status though zinc was not the intervention.

Study Details

PMID:9014651
Participants:60
Impact:no significant change
Trust score:4/5

urinary magnesium excretion

1 evidences

One-year calcium supplementation in lactating Gambian women did not change urinary magnesium excretion or iron/zinc blood markers.

Trust comment: Randomized double-blind placebo-controlled trial with complete compliance and repeated measures; directly measured zinc status though zinc was not the intervention.

Study Details

PMID:9014651
Participants:60
Impact:no significant change
Trust score:4/5

gingivitis (gingival index)

1 evidences

A fluoride/zinc dentifrice reduced gingivitis and dental plaque versus a fluoride-only dentifrice after six months of twice-daily use.

Trust comment: Double-blind randomized parallel-group clinical trial with clear, clinically meaningful percentage reductions.

Study Details

PMID:26856016
Participants:86
Impact:−23.8% vs zinc-free control (statistically significant)
Trust score:4/5

dental plaque (plaque index)

1 evidences

A fluoride/zinc dentifrice reduced gingivitis and dental plaque versus a fluoride-only dentifrice after six months of twice-daily use.

Trust comment: Double-blind randomized parallel-group clinical trial with clear, clinically meaningful percentage reductions.

Study Details

PMID:26856016
Participants:86
Impact:−22.5% vs zinc-free control (statistically significant)
Trust score:4/5

recovery rate from very ill status (boys)

1 evidences

In hospitalized infants with severe ALRI, zinc shortened duration of very ill status and fever in boys (not girls) and raised serum zinc at discharge.

Trust comment: Randomized double-blind placebo-controlled factorial trial with significant sex-specific effects and objective biochemical endpoints.

Study Details

PMID:14985218
Participants:153
Impact:2.6-fold increase vs non-zinc-treated
Trust score:4/5

fever recovery rate (boys)

1 evidences

In hospitalized infants with severe ALRI, zinc shortened duration of very ill status and fever in boys (not girls) and raised serum zinc at discharge.

Trust comment: Randomized double-blind placebo-controlled factorial trial with significant sex-specific effects and objective biochemical endpoints.

Study Details

PMID:14985218
Participants:153
Impact:3.0-fold increase vs non-zinc-treated
Trust score:4/5

serum zinc concentration at discharge

1 evidences

In hospitalized infants with severe ALRI, zinc shortened duration of very ill status and fever in boys (not girls) and raised serum zinc at discharge.

Trust comment: Randomized double-blind placebo-controlled factorial trial with significant sex-specific effects and objective biochemical endpoints.

Study Details

PMID:14985218
Participants:153
Impact:+6.06 µmol/L (significant)
Trust score:4/5

plasma leptin concentration

1 evidences

Supplemental zinc (3 mg/day) did not affect plasma leptin, ghrelin, insulin, or anthropometric growth indices over 6 months in these infants.

Trust comment: Randomized trial in at-risk infants with repeated measures and adequate sample size showing null effects of zinc on hormones and short-term growth.

Study Details

PMID:17921390
Participants:142
Impact:no significant change
Trust score:4/5

plasma ghrelin concentration

1 evidences

Supplemental zinc (3 mg/day) did not affect plasma leptin, ghrelin, insulin, or anthropometric growth indices over 6 months in these infants.

Trust comment: Randomized trial in at-risk infants with repeated measures and adequate sample size showing null effects of zinc on hormones and short-term growth.

Study Details

PMID:17921390
Participants:142
Impact:no significant change
Trust score:4/5

anthropometric z scores (growth)

1 evidences

Supplemental zinc (3 mg/day) did not affect plasma leptin, ghrelin, insulin, or anthropometric growth indices over 6 months in these infants.

Trust comment: Randomized trial in at-risk infants with repeated measures and adequate sample size showing null effects of zinc on hormones and short-term growth.

Study Details

PMID:17921390
Participants:142
Impact:no significant change
Trust score:4/5

90-day overall survival

1 evidences

Anakinra plus zinc had lower 90-day overall and transplant-free survival and higher acute kidney injury incidence compared with prednisone in severe alcohol-associated hepatitis; zinc was given as part of combination therapy.

Trust comment: Phase IIb double-blind randomized trial stopped early for inferiority of the anakinra+zinc arm; zinc was coadministered so effects cannot be isolated to zinc alone.

Study Details

PMID:38342441
Participants:147
Impact:A+Z 70% vs prednisone 90% (lower with A+Z)
Trust score:4/5

90-day transplant-free survival

1 evidences

Anakinra plus zinc had lower 90-day overall and transplant-free survival and higher acute kidney injury incidence compared with prednisone in severe alcohol-associated hepatitis; zinc was given as part of combination therapy.

Trust comment: Phase IIb double-blind randomized trial stopped early for inferiority of the anakinra+zinc arm; zinc was coadministered so effects cannot be isolated to zinc alone.

Study Details

PMID:38342441
Participants:147
Impact:A+Z 64% vs prednisone 88% (lower with A+Z)
Trust score:4/5

acute kidney injury incidence

1 evidences

Anakinra plus zinc had lower 90-day overall and transplant-free survival and higher acute kidney injury incidence compared with prednisone in severe alcohol-associated hepatitis; zinc was given as part of combination therapy.

Trust comment: Phase IIb double-blind randomized trial stopped early for inferiority of the anakinra+zinc arm; zinc was coadministered so effects cannot be isolated to zinc alone.

Study Details

PMID:38342441
Participants:147
Impact:A+Z 45% vs prednisone 22% (higher with A+Z)
Trust score:4/5

asthma control (C-ACT score)

1 evidences

Supplementation including zinc (with omega-3 and vitamin C) improved asthma control, pulmonary function, and sputum inflammatory markers in children with moderate persistent asthma.

Trust comment: Randomized self-controlled study with small sample and combined interventions, limiting attribution of effects specifically to zinc.

Study Details

PMID:19154523
Participants:60
Impact:significant improvement (p<0.001)
Trust score:3/5

Pulmonary function tests

1 evidences

Supplementation including zinc (with omega-3 and vitamin C) improved asthma control, pulmonary function, and sputum inflammatory markers in children with moderate persistent asthma.

Trust comment: Randomized self-controlled study with small sample and combined interventions, limiting attribution of effects specifically to zinc.

Study Details

PMID:19154523
Participants:60
Impact:significant improvement (p<0.001)
Trust score:3/5

Sputum inflammatory markers

1 evidences

Supplementation including zinc (with omega-3 and vitamin C) improved asthma control, pulmonary function, and sputum inflammatory markers in children with moderate persistent asthma.

Trust comment: Randomized self-controlled study with small sample and combined interventions, limiting attribution of effects specifically to zinc.

Study Details

PMID:19154523
Participants:60
Impact:significant improvement (p<0.001)
Trust score:3/5

serum homocysteine concentration

1 evidences

Zinc supplementation (50 mg/day for 8 weeks) increased circulating folate and decreased homocysteine but did not change vitamin B12 in postmenopausal women.

Trust comment: Small randomized trial with short duration and limited sample size; authors note need for larger studies to confirm findings.

Study Details

PMID:35149326
Participants:51
Impact:significant decrease
Trust score:3/5

serum vitamin B12 concentration

1 evidences

Zinc supplementation (50 mg/day for 8 weeks) increased circulating folate and decreased homocysteine but did not change vitamin B12 in postmenopausal women.

Trust comment: Small randomized trial with short duration and limited sample size; authors note need for larger studies to confirm findings.

Study Details

PMID:35149326
Participants:51
Impact:no significant change
Trust score:3/5

clinically meaningful THQ improvement (≥20 points)

1 evidences

Elderly tinnitus patients given 50 mg/day zinc showed no significant improvement in tinnitus compared with placebo.

Trust comment: Randomized double-blind placebo-controlled crossover trial with reasonable sample size but low observed power for the outcome.

Study Details

PMID:23598691
Participants:116
Impact:5/93 responders after zinc vs 2/94 after placebo; no significant difference (p>0.05)
Trust score:4/5

gingivitis and plaque

1 evidences

Alcohol did not change the effectiveness of a triclosan + zinc mouthwash on plaque or gingivitis, but alcohol-containing formula produced more adverse events (oral itching).

Trust comment: Small, double-blind crossover RCT directly testing zinc-containing mouthwashes but limited by sample size.

Study Details

PMID:15882208
Participants:30
Impact:no significant difference between hydroalcoholic and non-alcoholic formulations (gingival index and plaque index changes similar)
Trust score:3/5

adverse events (oral itching)

1 evidences

Alcohol did not change the effectiveness of a triclosan + zinc mouthwash on plaque or gingivitis, but alcohol-containing formula produced more adverse events (oral itching).

Trust comment: Small, double-blind crossover RCT directly testing zinc-containing mouthwashes but limited by sample size.

Study Details

PMID:15882208
Participants:30
Impact:higher with hydroalcoholic mouthwash (p=0.033)
Trust score:3/5

BMI

1 evidences

Zinc alone and zinc+curcumin for 90 days improved multiple glycemic measures and reduced BMI compared with placebo in prediabetic overweight/obese adults.

Trust comment: Randomized, placebo-controlled multi-arm trial with clear outcome improvements, though co-supplementation and lifestyle recommendations were present.

Study Details

PMID:33893671
Participants:82
Impact:decreased vs placebo (p=0.01 for zinc; p=0.007 for zinc+curcumin)
Trust score:4/5

fasting plasma glucose, 2-hour postprandial glucose, HbA1c, insulin, insulin sensitivity/resistance

1 evidences

Zinc alone and zinc+curcumin for 90 days improved multiple glycemic measures and reduced BMI compared with placebo in prediabetic overweight/obese adults.

Trust comment: Randomized, placebo-controlled multi-arm trial with clear outcome improvements, though co-supplementation and lifestyle recommendations were present.

Study Details

PMID:33893671
Participants:82
Impact:improved in treated groups vs placebo (FPG p=0.01; 2hpp p=0.003; HbA1c p=0.004; insulin p=0.001; IS% p=0.001; IR p<0.001)
Trust score:4/5

dietary intervention effect

1 evidences

Antihypertensive monotherapy was associated with decreased serum zinc and increased urinary zinc; an optimal-mineral diet restored serum zinc.

Trust comment: Controlled clinical monitoring in a small sample shows plausible drug–mineral interactions but is limited by sample size and short follow-up.

Study Details

PMID:24452943
Participants:45
Impact:optimal-mineral diet markedly increased serum zinc
Trust score:3/5

ferritin (iron status)

1 evidences

In a 12-month weight-loss trial, diets with differing zinc content maintained normal zinc status; higher-protein diet improved some iron markers but zinc did not change between groups.

Trust comment: Randomized diet trial with small completer sample (n=36) and objective biomarkers, but limited sample size reduces precision.

Study Details

PMID:24231018
Participants:36
Impact:HP median 52.0 vs LP 39.0 μg/L (higher in HP; p=0.021)
Trust score:3/5

sTfR-F (iron indicator)

1 evidences

In a 12-month weight-loss trial, diets with differing zinc content maintained normal zinc status; higher-protein diet improved some iron markers but zinc did not change between groups.

Trust comment: Randomized diet trial with small completer sample (n=36) and objective biomarkers, but limited sample size reduces precision.

Study Details

PMID:24231018
Participants:36
Impact:HP median 0.89 vs LP 1.05 (lower in HP; p=0.024)
Trust score:3/5

diarrhea (physician-diagnosed)

1 evidences

Daily zinc from 6 weeks of age reduced physician-diagnosed diarrhea, dysentery and acute upper respiratory infections in Tanzanian infants; multivitamins had no benefit.

Trust comment: Large, double-blind randomized controlled trial with clear clinical endpoints, supporting high internal validity.

Study Details

PMID:26203094
Participants:2360
Impact:-12% (RR 0.88; 95% CI 0.81–0.96; P=0.003)
Trust score:5/5

dysentery (physician-diagnosed)

1 evidences

Daily zinc from 6 weeks of age reduced physician-diagnosed diarrhea, dysentery and acute upper respiratory infections in Tanzanian infants; multivitamins had no benefit.

Trust comment: Large, double-blind randomized controlled trial with clear clinical endpoints, supporting high internal validity.

Study Details

PMID:26203094
Participants:2360
Impact:-16% (RR 0.84; 95% CI 0.74–0.95; P=0.006)
Trust score:5/5

acute upper respiratory infection (physician-diagnosed)

1 evidences

Daily zinc from 6 weeks of age reduced physician-diagnosed diarrhea, dysentery and acute upper respiratory infections in Tanzanian infants; multivitamins had no benefit.

Trust comment: Large, double-blind randomized controlled trial with clear clinical endpoints, supporting high internal validity.

Study Details

PMID:26203094
Participants:2360
Impact:-8% (RR 0.92; 95% CI 0.88–0.97; P=0.0005)
Trust score:5/5

Serum retinol (vitamin A)

1 evidences

Daily prenatal multiple micronutrients did not improve maternal serum zinc or retinol compared with iron-only supplementation; possible small improvement in folate postpartum.

Trust comment: Randomized prenatal supplementation with supervised dosing and biochemical outcomes, though biochemical sub-sampling and generally adequate baseline status limit detectable effects.

Study Details

PMID:19668928
Participants:507
Impact:no difference between MM and Fe groups
Trust score:4/5

folate status (postpartum)

1 evidences

Daily prenatal multiple micronutrients did not improve maternal serum zinc or retinol compared with iron-only supplementation; possible small improvement in folate postpartum.

Trust comment: Randomized prenatal supplementation with supervised dosing and biochemical outcomes, though biochemical sub-sampling and generally adequate baseline status limit detectable effects.

Study Details

PMID:19668928
Participants:507
Impact:trend toward lower folate deficiency in MM (10.0%) vs Fe (18.5%) (p=0.09)
Trust score:4/5

zinc intake (dietary)

1 evidences

Cluster-RCT assessing dietary intakes over 12 months in children given LNS (contains multiple micronutrients) vs control; dietary recalls used.

Trust comment: Cluster-randomized trial with repeated dietary assessments showing improved micronutrient intakes, but intake data (not biomarkers) and LNS is a multi-nutrient product.

Study Details

PMID:25819697
Participants:298
Impact:change from baseline to follow-ups larger in LNS arm vs control (intake increased relative to control)
Trust score:4/5

length-for-age z score

2 evidences

A 6-month lipid-based nutrient supplement (providing zinc among other nutrients) modestly increased length- and weight-for-age in young children, with effects persisting 6 months later.

Trust comment: Large randomized controlled trial with clear growth outcomes, but supplement contained multiple nutrients so zinc-specific effects cannot be isolated.

Study Details

PMID:24225356
Participants:589
Impact:+0.13 ± 0.05 (significant vs control)
Trust score:4/5

Six-month RCT in Vietnamese infants testing daily or weekly multiple micronutrients (including a small zinc dose) vs placebo; growth and blood micronutrients measured.

Trust comment: Large randomized, double-blind trial with clear biomarker and growth outcomes, but zinc was one component of a multi-micronutrient supplement and dose appears small.

Study Details

PMID:15735111
Participants:306
Impact:decrease smaller in DMM (-0.32) vs placebo (-0.49) and WMM (-0.51)
Trust score:4/5

probing pocket depth

1 evidences

Adding a dentifrice and rinse containing sanguinaria extract and zinc chloride to initial periodontal therapy provided no additional short-term benefit over placebo.

Trust comment: Randomized double-blind trial but small sample size limits power to detect small effects; zinc present as part of product rather than isolated intervention.

Study Details

PMID:9078647
Participants:34
Impact:no difference between groups
Trust score:3/5

hepatic copper content (64Cu PET/CT)

1 evidences

Randomized study in healthy adults showing that several oral zinc regimens halved hepatic copper uptake by PET/CT; adverse GI effects were common and varied by zinc salt and dosing.

Trust comment: Randomized human intervention with objective PET/CT primary outcome and clear per-protocol analyses, but modest sample size and non-blinded design.

Study Details

PMID:36038585
Participants:37
Impact:Overall ≈50% reduction; acet.50mg×3: reduced to 56% of baseline (≈−44%); acet.150mg×1: 56% (≈−44%); gluconate.50mg×3: 49% (≈−51%); gluconate.150mg×1: 85% (≈−15%, not significant)
Trust score:4/5

common cold duration / symptom resolution

1 evidences

Double-blind placebo-controlled trial found intranasal zinc gluconate plus zinc orotate lozenges did not shorten common cold duration and caused nasal/olfactory pain in some participants.

Trust comment: Double-blind, placebo-controlled human trial with clinical endpoints but relatively small sample and negative result.

Study Details

PMID:16454145
Participants:77
Impact:No significant benefit (63% vs 53% asymptomatic at 7 days; P=0.57)
Trust score:4/5

nasal/olfactory pain

1 evidences

Double-blind placebo-controlled trial found intranasal zinc gluconate plus zinc orotate lozenges did not shorten common cold duration and caused nasal/olfactory pain in some participants.

Trust comment: Double-blind, placebo-controlled human trial with clinical endpoints but relatively small sample and negative result.

Study Details

PMID:16454145
Participants:77
Impact:Reported in some zinc-treated patients
Trust score:4/5

anosmia

1 evidences

Double-blind placebo-controlled trial found intranasal zinc gluconate plus zinc orotate lozenges did not shorten common cold duration and caused nasal/olfactory pain in some participants.

Trust comment: Double-blind, placebo-controlled human trial with clinical endpoints but relatively small sample and negative result.

Study Details

PMID:16454145
Participants:77
Impact:No anosmia observed in this trial
Trust score:4/5

≥40% reduction in ulcer area

1 evidences

Randomized blinded trial in malnourished adults with pressure ulcers found an arginine-/zinc-/antioxidant‑enriched high-calorie formula improved ulcer area reduction versus isocaloric control over 8 weeks.

Trust comment: Well-conducted multicenter RCT, but zinc was one component of a multi-nutrient formula so effects cannot be attributed to zinc alone.

Study Details

PMID:25643304
Participants:200
Impact:More frequent with enriched formula (OR 1.98; 95% CI 1.12 to 3.48; P=0.018)
Trust score:3/5

anemia prevalence / hemoglobin

1 evidences

Cluster-randomized trial (biochemistry subgroup) in infants found varying zinc doses in SQ-LNS did not change plasma zinc, while the SQ-LNS plus illness treatment improved iron and vitamin A status and reduced anemia prevalence compared with non-intervention cohort.

Trust comment: Large cluster-randomized trial with biochemical outcomes and appropriate adjustments, though zinc adherence/absorption issues limit interpretation of zinc-specific effects.

Study Details

PMID:28152989
Participants:404
Impact:Anemia prevalence decreased ~20% in the intervention cohort; Hb increased (IC mean at 18 mo ≈97 g/L vs NIC ≈90 g/L; P≈0.003 for cohort)
Trust score:4/5

iron status and vitamin A status

1 evidences

Cluster-randomized trial (biochemistry subgroup) in infants found varying zinc doses in SQ-LNS did not change plasma zinc, while the SQ-LNS plus illness treatment improved iron and vitamin A status and reduced anemia prevalence compared with non-intervention cohort.

Trust comment: Large cluster-randomized trial with biochemical outcomes and appropriate adjustments, though zinc adherence/absorption issues limit interpretation of zinc-specific effects.

Study Details

PMID:28152989
Participants:404
Impact:Improved iron indicators (higher ferritin/BIS) and higher RBP in intervention cohort versus NIC
Trust score:4/5

plasma mineral homeostasis

1 evidences

Feeding preterm infants a nutrient-enriched formula normalized plasma zinc by 2 months past term without disrupting overall mineral homeostasis.

Trust comment: Prospective feeding trial in humans with clear measurement of plasma minerals but modest sample size and limited detail on long-term outcomes.

Study Details

PMID:7752008
Participants:33
Impact:no adverse effects / unchanged
Trust score:3/5

total testosterone

1 evidences

Men receiving D-aspartic acid + ubiquinol + 10 mg zinc daily for 3 months showed improved progressive sperm motility and higher total testosterone versus placebo.

Trust comment: Randomized double-blind design but small group sizes and effects reported for a multi-ingredient regimen so attribution to zinc alone is limited.

Study Details

PMID:40248985
Participants:48
Impact:+16% (5.06 → 5.89; p=0.009)
Trust score:3/5

birthweight / pregnancy outcomes

1 evidences

Daily 25 mg zinc in HIV-infected pregnant women did not change birth outcomes or T‑cell counts but was associated with a smaller postpartum rise in hemoglobin and related red-cell indices.

Trust comment: Large randomized trial in humans with appropriate endpoints and clear reporting, though effects were mostly null and some hematologic differences were small.

Study Details

PMID:15640476
Participants:400
Impact:no significant difference
Trust score:4/5

hemoglobin rise postpartum

1 evidences

Daily 25 mg zinc in HIV-infected pregnant women did not change birth outcomes or T‑cell counts but was associated with a smaller postpartum rise in hemoglobin and related red-cell indices.

Trust comment: Large randomized trial in humans with appropriate endpoints and clear reporting, though effects were mostly null and some hematologic differences were small.

Study Details

PMID:15640476
Participants:400
Impact:smaller increase: +11.5 g/L (zinc) vs +15.2 g/L (placebo); difference ≈ −3.7 g/L (p=0.03)
Trust score:4/5

T lymphocyte counts (CD4/CD8/CD3)

1 evidences

Daily 25 mg zinc in HIV-infected pregnant women did not change birth outcomes or T‑cell counts but was associated with a smaller postpartum rise in hemoglobin and related red-cell indices.

Trust comment: Large randomized trial in humans with appropriate endpoints and clear reporting, though effects were mostly null and some hematologic differences were small.

Study Details

PMID:15640476
Participants:400
Impact:no effect
Trust score:4/5

mean birthweight (overall)

1 evidences

A double-blind RCT of iron‑zinc vs iron-only showed no overall birthweight difference, but iron‑deficient/anaemic women receiving iron‑zinc had higher adjusted mean birthweight (+131 g).

Trust comment: Large, well-conducted double-blind RCT with subgroup interaction analyses and high completion rate; robust methodology.

Study Details

PMID:19902797
Participants:543
Impact:no overall difference
Trust score:5/5

mean birthweight in iron-deficient/anaemic women

1 evidences

A double-blind RCT of iron‑zinc vs iron-only showed no overall birthweight difference, but iron‑deficient/anaemic women receiving iron‑zinc had higher adjusted mean birthweight (+131 g).

Trust comment: Large, well-conducted double-blind RCT with subgroup interaction analyses and high completion rate; robust methodology.

Study Details

PMID:19902797
Participants:543
Impact:+131 g (3,223 g vs 3,092 g; adjusted, p=0.042)
Trust score:5/5

plasma zinc concentration (subgroups)

1 evidences

A double-blind RCT of iron‑zinc vs iron-only showed no overall birthweight difference, but iron‑deficient/anaemic women receiving iron‑zinc had higher adjusted mean birthweight (+131 g).

Trust comment: Large, well-conducted double-blind RCT with subgroup interaction analyses and high completion rate; robust methodology.

Study Details

PMID:19902797
Participants:543
Impact:higher in iron‑zinc group in some subgroups (e.g., 41.2 µg/dL vs 31.2 µg/dL among low baseline zinc; not statistically significant)
Trust score:5/5

total symptom score (4 days)

1 evidences

In a randomized study where both arms received zinc (different doses) and one arm received troxerutin, overall symptom scores did not differ significantly but rhinorrhea and day‑1 symptom reduction favored the active treatment.

Trust comment: Randomized human study but small size and multi-component interventions (different zinc doses + troxerutin) limit attribution of effects to zinc alone.

Study Details

PMID:15601310
Participants:94
Impact:no significant difference (27.7 vs 33.0; p=0.10)
Trust score:3/5

day 1 symptom reduction

1 evidences

In a randomized study where both arms received zinc (different doses) and one arm received troxerutin, overall symptom scores did not differ significantly but rhinorrhea and day‑1 symptom reduction favored the active treatment.

Trust comment: Randomized human study but small size and multi-component interventions (different zinc doses + troxerutin) limit attribution of effects to zinc alone.

Study Details

PMID:15601310
Participants:94
Impact:active: −11% vs control: −1% (p=0.03)
Trust score:3/5

rhinorrhea

1 evidences

In a randomized study where both arms received zinc (different doses) and one arm received troxerutin, overall symptom scores did not differ significantly but rhinorrhea and day‑1 symptom reduction favored the active treatment.

Trust comment: Randomized human study but small size and multi-component interventions (different zinc doses + troxerutin) limit attribution of effects to zinc alone.

Study Details

PMID:15601310
Participants:94
Impact:reduced: total 3.7 vs 5.1 (p=0.025)
Trust score:3/5

plasma vitamin A

1 evidences

In healthy elderly volunteers given 15 mg or 30 mg/day zinc for 6 months, zinc did not change most red-ox markers but dose-related increases in plasma vitamin A were observed.

Trust comment: Double-blind randomized study in humans with moderate sample size and clear biomarker measurements, though population was healthy elderly with likely adequate zinc status.

Study Details

PMID:24676313
Participants:108
Impact:increased: 1.94 → 2.18 µM (15 mg) and 1.95 → 2.26 µM (30 mg)
Trust score:4/5

other red-ox markers (GSH, RSH, MDA, hemolysis, methemoglobin, carotenoids, vitamins E)

1 evidences

In healthy elderly volunteers given 15 mg or 30 mg/day zinc for 6 months, zinc did not change most red-ox markers but dose-related increases in plasma vitamin A were observed.

Trust comment: Double-blind randomized study in humans with moderate sample size and clear biomarker measurements, though population was healthy elderly with likely adequate zinc status.

Study Details

PMID:24676313
Participants:108
Impact:no significant change
Trust score:4/5

plaque lactate concentration

1 evidences

A dentifrice containing 2% zinc citrate (with triclosan) lowered plaque lactate after a food challenge and lessened the post-snack pH drop.

Trust comment: Controlled intervention with objective biochemical measures but modest sample size (n=30) and limited duration.

Study Details

PMID:14725383
Participants:30
Impact:−15.6 mM (control 39.2 mM → test 23.6 mM; significant)
Trust score:3/5

plaque pH after food challenge

1 evidences

A dentifrice containing 2% zinc citrate (with triclosan) lowered plaque lactate after a food challenge and lessened the post-snack pH drop.

Trust comment: Controlled intervention with objective biochemical measures but modest sample size (n=30) and limited duration.

Study Details

PMID:14725383
Participants:30
Impact:+0.26 pH units (control 5.53 → test 5.79; significant)
Trust score:3/5

zinc-to-copper ratio

1 evidences

In a 6-week double-blind RCT, curcumin (both forms) increased serum zinc and the zinc-to-copper ratio in people with metabolic syndrome.

Trust comment: Double-blind randomized clinical trial with clear measurement of serum trace elements in 120 participants.

Study Details

PMID:30020812
Participants:120
Impact:increase (significant)
Trust score:4/5

iron absorption (with zinc sulfate cofortification)

1 evidences

In a randomized feeding study in children, cofortifying flour with zinc sulfate (but not zinc oxide) reduced iron absorption; zinc absorption was similar between zinc forms.

Trust comment: Randomized study using stable-isotope methods with high completion (86), providing reliable bioavailability data.

Study Details

PMID:12324295
Participants:86
Impact:decreased to 11.5% (vs 15.9% for iron-only flour)
Trust score:4/5

zinc absorption (zinc oxide vs zinc sulfate)

1 evidences

In a randomized feeding study in children, cofortifying flour with zinc sulfate (but not zinc oxide) reduced iron absorption; zinc absorption was similar between zinc forms.

Trust comment: Randomized study using stable-isotope methods with high completion (86), providing reliable bioavailability data.

Study Details

PMID:12324295
Participants:86
Impact:no significant difference (~24% both groups)
Trust score:4/5

RBC membrane PUFA abundance (C22:5, C20:4, C22:4, total n-6)

1 evidences

In patients with type 2 diabetes, 24 months of 30 mg/day zinc increased membrane polyunsaturated fatty acids and measures of membrane unsaturation, and upregulated FADS1 expression.

Trust comment: Randomized 24-month trial with biochemical and gene-expression endpoints but modest sample size (60).

Study Details

PMID:32534376
Participants:60
Impact:increased (statistically significant: p = 0.001 to 0.048 for reported fatty acids)
Trust score:4/5

unsaturation index and UFA/SFA ratio

1 evidences

In patients with type 2 diabetes, 24 months of 30 mg/day zinc increased membrane polyunsaturated fatty acids and measures of membrane unsaturation, and upregulated FADS1 expression.

Trust comment: Randomized 24-month trial with biochemical and gene-expression endpoints but modest sample size (60).

Study Details

PMID:32534376
Participants:60
Impact:increased (p = 0.000 and p = 0.003 respectively)
Trust score:4/5

FADS1 (D5D) gene expression

1 evidences

In patients with type 2 diabetes, 24 months of 30 mg/day zinc increased membrane polyunsaturated fatty acids and measures of membrane unsaturation, and upregulated FADS1 expression.

Trust comment: Randomized 24-month trial with biochemical and gene-expression endpoints but modest sample size (60).

Study Details

PMID:32534376
Participants:60
Impact:upregulated (significant at month 12, p = 0.020)
Trust score:4/5

VEGF

1 evidences

In DR patients, 30 mg/day zinc for 3 months did not change serum VEGF, BDNF, or NGF levels.

Trust comment: Randomized clinical trial with clearly measured biomarkers but small sample (45 completers).

Study Details

PMID:29421993
Participants:45
Impact:no change
Trust score:4/5

BDNF

1 evidences

In DR patients, 30 mg/day zinc for 3 months did not change serum VEGF, BDNF, or NGF levels.

Trust comment: Randomized clinical trial with clearly measured biomarkers but small sample (45 completers).

Study Details

PMID:29421993
Participants:45
Impact:no change
Trust score:4/5

NGF

1 evidences

In DR patients, 30 mg/day zinc for 3 months did not change serum VEGF, BDNF, or NGF levels.

Trust comment: Randomized clinical trial with clearly measured biomarkers but small sample (45 completers).

Study Details

PMID:29421993
Participants:45
Impact:no change
Trust score:4/5

hearing gain

1 evidences

Adding oral zinc gluconate to corticosteroid therapy improved hearing recovery in patients with sudden sensorineural hearing loss.

Trust comment: Prospective randomized study reporting statistically significant improvements, but modest sample size (n=66).

Study Details

PMID:20928835
Participants:66
Impact:increased (significant)
Trust score:4/5

percentage of recovery

1 evidences

Adding oral zinc gluconate to corticosteroid therapy improved hearing recovery in patients with sudden sensorineural hearing loss.

Trust comment: Prospective randomized study reporting statistically significant improvements, but modest sample size (n=66).

Study Details

PMID:20928835
Participants:66
Impact:increased (significant)
Trust score:4/5

rate of successful recovery

1 evidences

Adding oral zinc gluconate to corticosteroid therapy improved hearing recovery in patients with sudden sensorineural hearing loss.

Trust comment: Prospective randomized study reporting statistically significant improvements, but modest sample size (n=66).

Study Details

PMID:20928835
Participants:66
Impact:increased (significant)
Trust score:4/5

aerosol viable bacteria (CFU)

1 evidences

A pre-procedural mouthwash containing CPC + zinc lactate + fluoride reduced viable bacteria in dental aerosols by ~70% versus no rinse after ultrasonic scaling.

Trust comment: Randomized trial (n=60) with large relative reductions in aerosol CFUs; mouthwash had multiple actives so zinc-specific effect is uncertain.

Study Details

PMID:28380086
Participants:60
Impact:~70% reduction vs no rinse (61% vs water)
Trust score:4/5

days of diarrhea

1 evidences

In two community trials (total enrolled 631), adding zinc (1 mg/15 g cereal) did not change days of diarrhea, Hib antibody titers, growth, clinic visits, hospitalizations, or antibiotic use.

Trust comment: Large, randomized community trials with blinded design reporting null effects for the measured clinical and immunologic endpoints.

Study Details

PMID:12663295
Participants:631
Impact:no change
Trust score:4/5

Hib antibody titer (post-immunization)

1 evidences

In two community trials (total enrolled 631), adding zinc (1 mg/15 g cereal) did not change days of diarrhea, Hib antibody titers, growth, clinic visits, hospitalizations, or antibiotic use.

Trust comment: Large, randomized community trials with blinded design reporting null effects for the measured clinical and immunologic endpoints.

Study Details

PMID:12663295
Participants:631
Impact:no change
Trust score:4/5

growth (height gain)

1 evidences

In two community trials (total enrolled 631), adding zinc (1 mg/15 g cereal) did not change days of diarrhea, Hib antibody titers, growth, clinic visits, hospitalizations, or antibiotic use.

Trust comment: Large, randomized community trials with blinded design reporting null effects for the measured clinical and immunologic endpoints.

Study Details

PMID:12663295
Participants:631
Impact:no change
Trust score:4/5

P. falciparum episodes (>9200/µL with fever)

1 evidences

Daily zinc (10 mg, 6 days/week for 46 weeks) reduced P. falciparum malaria episodes substantially in preschool children.

Trust comment: Randomized placebo-controlled trial with adequate sample size and reported CIs showing significant reductions in P. falciparum morbidity.

Study Details

PMID:11304051
Participants:274
Impact:-38% (95% CI 3–60%)
Trust score:5/5

episodes with any parasitemia

1 evidences

Daily zinc (10 mg, 6 days/week for 46 weeks) reduced P. falciparum malaria episodes substantially in preschool children.

Trust comment: Randomized placebo-controlled trial with adequate sample size and reported CIs showing significant reductions in P. falciparum morbidity.

Study Details

PMID:11304051
Participants:274
Impact:-38% (95% CI 5–60%)
Trust score:5/5

episodes with parasitemia ≥100,000/µL

1 evidences

Daily zinc (10 mg, 6 days/week for 46 weeks) reduced P. falciparum malaria episodes substantially in preschool children.

Trust comment: Randomized placebo-controlled trial with adequate sample size and reported CIs showing significant reductions in P. falciparum morbidity.

Study Details

PMID:11304051
Participants:274
Impact:-69% (95% CI 25–87%)
Trust score:5/5

wound-healing rate

1 evidences

A wound-specific oral supplement containing arginine, vitamin C and zinc was less effective for wound-healing than a standard nutrition supplement in patients with chronic wounds.

Trust comment: Small (n=24), open pragmatic RCT; unexpected superiority of the standard supplement limits conclusions about zinc alone.

Study Details

PMID:23627791
Participants:24
Impact:worse with wound-specific (zinc-containing) supplement vs standard (P=0.044)
Trust score:3/5

nutritional status

1 evidences

A wound-specific oral supplement containing arginine, vitamin C and zinc was less effective for wound-healing than a standard nutrition supplement in patients with chronic wounds.

Trust comment: Small (n=24), open pragmatic RCT; unexpected superiority of the standard supplement limits conclusions about zinc alone.

Study Details

PMID:23627791
Participants:24
Impact:no change
Trust score:3/5

Quality of life

1 evidences

A wound-specific oral supplement containing arginine, vitamin C and zinc was less effective for wound-healing than a standard nutrition supplement in patients with chronic wounds.

Trust comment: Small (n=24), open pragmatic RCT; unexpected superiority of the standard supplement limits conclusions about zinc alone.

Study Details

PMID:23627791
Participants:24
Impact:no change
Trust score:3/5

adverse events (diarrhoea)

1 evidences

Zinc-containing fortifications (MNPs or fortified CSB) increased serum zinc in moderately malnourished children; one MNP formulation without zinc decreased serum zinc.

Trust comment: Cluster randomized controlled trial with good adherence and objective serum measures, but limitations include non–trace-element vacutainers and retrospective registration.

Study Details

PMID:36121865
Participants:276
Impact:Few reports (n=6); no serious adverse events attributed to interventions
Trust score:4/5

whole-body protein turnover

1 evidences

Six months of zinc (0, 15, or 30 mg/d) in late-middle-aged men did not alter whole-body protein turnover or albumin and fibrinogen synthesis rates.

Trust comment: Randomized, double-blind, placebo-controlled trial with direct metabolic measures; sample moderate but well-controlled.

Study Details

PMID:18077134
Participants:48
Impact:No significant change
Trust score:4/5

albumin synthesis rate

1 evidences

Six months of zinc (0, 15, or 30 mg/d) in late-middle-aged men did not alter whole-body protein turnover or albumin and fibrinogen synthesis rates.

Trust comment: Randomized, double-blind, placebo-controlled trial with direct metabolic measures; sample moderate but well-controlled.

Study Details

PMID:18077134
Participants:48
Impact:No significant change
Trust score:4/5

fibrinogen synthesis rate

1 evidences

Six months of zinc (0, 15, or 30 mg/d) in late-middle-aged men did not alter whole-body protein turnover or albumin and fibrinogen synthesis rates.

Trust comment: Randomized, double-blind, placebo-controlled trial with direct metabolic measures; sample moderate but well-controlled.

Study Details

PMID:18077134
Participants:48
Impact:No significant change
Trust score:4/5

head and chest circumference

1 evidences

Large cluster RCT of antenatal micronutrient regimens found folic acid–iron reduced low birthweight; folic acid–iron–zinc showed no additional benefit over control for birth size.

Trust comment: Large, double-blind cluster RCT with thousands enrolled; zinc was given in combination so isolated zinc effects are not separable.

Study Details

PMID:12637400
Participants:4130
Impact:Increased with folic acid–iron and multiple micronutrients; length unchanged
Trust score:4/5

erythrocyte SOD activity

1 evidences

Daily cashew consumption for 12 weeks in adolescents with obesity reduced plasma copper and increased erythrocyte SOD activity; plasma zinc increased across both groups (likely influenced by counseling).

Trust comment: Randomized controlled trial but with substantial dropout and potential confounding from concurrent nutritional counseling; objective biochemical endpoints measured.

Study Details

PMID:39796597
Participants:81
Impact:Increased in CASN group (p=0.030)
Trust score:4/5

micronucleus frequency (genomic instability)

1 evidences

Twelve weeks of zinc carnosine in older adults with low zinc increased plasma zinc modestly and reduced multiple markers of DNA damage while increasing expression of MT1A and ZIP1.

Trust comment: Placebo-controlled 12-week RCT in older adults with low zinc status reporting objective genomic and gene-expression endpoints; sample moderate.

Study Details

PMID:25755079
Participants:84
Impact:−24.18% (significant vs baseline)
Trust score:4/5

DNA damage metrics (comet tail moment/intensity)

1 evidences

Twelve weeks of zinc carnosine in older adults with low zinc increased plasma zinc modestly and reduced multiple markers of DNA damage while increasing expression of MT1A and ZIP1.

Trust comment: Placebo-controlled 12-week RCT in older adults with low zinc status reporting objective genomic and gene-expression endpoints; sample moderate.

Study Details

PMID:25755079
Participants:84
Impact:Tail moment −7.09%; tail intensity −8.76% (reductions vs baseline)
Trust score:4/5

Subscapular skinfold thickness

1 evidences

In low‑income Indian full‑term infants, daily zinc (5 mg) from 4–18 months increased skinfold thickness and reduced wasting at 24 months but did not improve linear growth.

Trust comment: Large double‑blind randomized controlled trial with objective anthropometric and biochemical outcomes, though supplementation interruptions and dietary confounding limit attribution to zinc alone.

Study Details

PMID:23737940
Participants:302
Impact:+0.33 cm (18 mo) and +0.32 cm (21 mo) vs placebo
Trust score:4/5

Triceps skinfold thickness

1 evidences

In low‑income Indian full‑term infants, daily zinc (5 mg) from 4–18 months increased skinfold thickness and reduced wasting at 24 months but did not improve linear growth.

Trust comment: Large double‑blind randomized controlled trial with objective anthropometric and biochemical outcomes, though supplementation interruptions and dietary confounding limit attribution to zinc alone.

Study Details

PMID:23737940
Participants:302
Impact:+0.43 cm (21 mo) and +0.39 cm (24 mo) vs placebo
Trust score:4/5

Wasting prevalence (WHZ <−2 SD) at 24 months

1 evidences

In low‑income Indian full‑term infants, daily zinc (5 mg) from 4–18 months increased skinfold thickness and reduced wasting at 24 months but did not improve linear growth.

Trust comment: Large double‑blind randomized controlled trial with objective anthropometric and biochemical outcomes, though supplementation interruptions and dietary confounding limit attribution to zinc alone.

Study Details

PMID:23737940
Participants:302
Impact:−10.1 percentage points (14.3% vs 24.6%; p=0.033) vs placebo
Trust score:4/5

Zinc deficiency prevalence (serum zinc <60 µg/dl)

1 evidences

In low‑income Indian full‑term infants, daily zinc (5 mg) from 4–18 months increased skinfold thickness and reduced wasting at 24 months but did not improve linear growth.

Trust comment: Large double‑blind randomized controlled trial with objective anthropometric and biochemical outcomes, though supplementation interruptions and dietary confounding limit attribution to zinc alone.

Study Details

PMID:23737940
Participants:302
Impact:reduced from 44.1% (placebo) to 26.5% (zinc)
Trust score:4/5

BCAA‑to‑tyrosine ratio (BTR)

1 evidences

In HCV patients, supplementation with BCAAs plus zinc (10 mg/day) for 60 days increased BCAA:tyrosine ratio and serum zinc; in those with elevated baseline AFP, supplementation reduced AFP.

Trust comment: Randomized multicenter trial with objective biochemical endpoints, but small sample and combined BCAA+zinc intervention limit zinc‑only attribution.

Study Details

PMID:25394681
Participants:53
Impact:increased vs placebo (5.14 ±1.59 vs 4.23 ±1.14; P=0.0290)
Trust score:3/5

α‑fetoprotein (AFP) in patients with elevated baseline AFP

1 evidences

In HCV patients, supplementation with BCAAs plus zinc (10 mg/day) for 60 days increased BCAA:tyrosine ratio and serum zinc; in those with elevated baseline AFP, supplementation reduced AFP.

Trust comment: Randomized multicenter trial with objective biochemical endpoints, but small sample and combined BCAA+zinc intervention limit zinc‑only attribution.

Study Details

PMID:25394681
Participants:53
Impact:ΔAFP −2.72 ±3.45 ng/ml (P=0.0079) in supplement group
Trust score:3/5

Food infiltration (poppy seed retention)

1 evidences

Both calcium-containing denture adhesives significantly reduced poppy-seed infiltration beneath partial dentures versus baseline; the calcium/zinc formulation was superior to the calcium/sodium formulation.

Trust comment: Well‑designed double‑blind randomized crossover trial with objective primary outcome and high completion rate, though small sample size.

Study Details

PMID:39186604
Participants:29
Impact:−85.9% vs baseline (6.18 → 0.86); greater reduction than calcium/sodium adhesive (P=0.008)
Trust score:4/5

copeptin

1 evidences

In zinc-deficient diabetic hemodialysis patients, 8 weeks of zinc sulfate altered several biomarkers compared with placebo.

Trust comment: Randomized double-blind placebo-controlled RCT in humans with clear p-values, but modest sample size (n=46).

Study Details

PMID:33655432
Participants:46
Impact:decreased (P < 0.001)
Trust score:4/5

high-sensitive C-reactive protein (hs-CRP)

1 evidences

In zinc-deficient diabetic hemodialysis patients, 8 weeks of zinc sulfate altered several biomarkers compared with placebo.

Trust comment: Randomized double-blind placebo-controlled RCT in humans with clear p-values, but modest sample size (n=46).

Study Details

PMID:33655432
Participants:46
Impact:decreased (P < 0.001)
Trust score:4/5

fasting blood glucose

1 evidences

In zinc-deficient diabetic hemodialysis patients, 8 weeks of zinc sulfate altered several biomarkers compared with placebo.

Trust comment: Randomized double-blind placebo-controlled RCT in humans with clear p-values, but modest sample size (n=46).

Study Details

PMID:33655432
Participants:46
Impact:decreased (P < 0.001)
Trust score:4/5

renal function (BUN and creatinine)

1 evidences

In zinc-deficient diabetic hemodialysis patients, 8 weeks of zinc sulfate altered several biomarkers compared with placebo.

Trust comment: Randomized double-blind placebo-controlled RCT in humans with clear p-values, but modest sample size (n=46).

Study Details

PMID:33655432
Participants:46
Impact:improved/changed (P < 0.001)
Trust score:4/5

general intelligence (composite z-score)

1 evidences

Long-term follow-up found no effect of infant zinc (or MMN) supplementation on child cognitive, executive function, or mental health outcomes at 6–8 years.

Trust comment: Large original RCTs but substantial loss to follow-up in the development study (limited power), leading to moderate confidence.

Study Details

PMID:30718805
Participants:365
Impact:no effect (p > 0.05)
Trust score:3/5

executive function (composite z-score)

1 evidences

Long-term follow-up found no effect of infant zinc (or MMN) supplementation on child cognitive, executive function, or mental health outcomes at 6–8 years.

Trust comment: Large original RCTs but substantial loss to follow-up in the development study (limited power), leading to moderate confidence.

Study Details

PMID:30718805
Participants:365
Impact:no effect (p > 0.05)
Trust score:3/5

mental health (BRIEF/SDQ composite)

1 evidences

Long-term follow-up found no effect of infant zinc (or MMN) supplementation on child cognitive, executive function, or mental health outcomes at 6–8 years.

Trust comment: Large original RCTs but substantial loss to follow-up in the development study (limited power), leading to moderate confidence.

Study Details

PMID:30718805
Participants:365
Impact:no effect (p > 0.05)
Trust score:3/5

serum alanine aminotransferase (ALT)

1 evidences

In chronic hepatitis C patients on antiviral therapy, polaprezinc (zinc) supplementation was associated with lower ALT and markers suggesting reduced oxidative liver injury.

Trust comment: Randomized supplement vs no-supplement in humans but very small sample size, so results are suggestive but limited precision.

Study Details

PMID:17874825
Participants:23
Impact:lower at 12 weeks and higher proportion normalized at 24 and 48 weeks in zinc group (significant)
Trust score:3/5

oxidative stress (TBARS)

1 evidences

In chronic hepatitis C patients on antiviral therapy, polaprezinc (zinc) supplementation was associated with lower ALT and markers suggesting reduced oxidative liver injury.

Trust comment: Randomized supplement vs no-supplement in humans but very small sample size, so results are suggestive but limited precision.

Study Details

PMID:17874825
Participants:23
Impact:decreased with polaprezinc
Trust score:3/5

HCV RNA disappearance (virologic response)

1 evidences

In chronic hepatitis C patients on antiviral therapy, polaprezinc (zinc) supplementation was associated with lower ALT and markers suggesting reduced oxidative liver injury.

Trust comment: Randomized supplement vs no-supplement in humans but very small sample size, so results are suggestive but limited precision.

Study Details

PMID:17874825
Participants:23
Impact:all patients with data in zinc group cleared HCV RNA at 48 wk (7/7) vs 8/10 in control (reported)
Trust score:3/5

systemic zinc level

1 evidences

Short-term AREDS2 dietary supplementation (which includes zinc) raised systemic zinc levels but did not alter systemic or ocular complement activation over 4 weeks.

Trust comment: Randomized, prospective but small, short-duration and open-label which limits generalizability.

Study Details

PMID:34034256
Participants:50
Impact:increased (AREDS2 vs control; mean 10.16 vs 8.66 μmol/L; p = 0.007)
Trust score:3/5

complement activation (C3, C3a, FH, FI, sC5b-9)

1 evidences

Short-term AREDS2 dietary supplementation (which includes zinc) raised systemic zinc levels but did not alter systemic or ocular complement activation over 4 weeks.

Trust comment: Randomized, prospective but small, short-duration and open-label which limits generalizability.

Study Details

PMID:34034256
Participants:50
Impact:no significant change
Trust score:3/5

complement component Ba

1 evidences

Short-term AREDS2 dietary supplementation (which includes zinc) raised systemic zinc levels but did not alter systemic or ocular complement activation over 4 weeks.

Trust comment: Randomized, prospective but small, short-duration and open-label which limits generalizability.

Study Details

PMID:34034256
Participants:50
Impact:increased from baseline (greater increase in control than AREDS2)
Trust score:3/5

overall wart response

1 evidences

Randomized trial in children comparing intralesional zinc sulfate 2% vs PPD for warts; both effective, zinc had faster injected-wart clearance but more complications.

Trust comment: Randomized clinical trial with adequate sample size and clear clinical outcomes; side-effect differences reported.

Study Details

PMID:35212136
Participants:120
Impact:81.7% (both groups)
Trust score:4/5

injected wart response

1 evidences

Randomized trial in children comparing intralesional zinc sulfate 2% vs PPD for warts; both effective, zinc had faster injected-wart clearance but more complications.

Trust comment: Randomized clinical trial with adequate sample size and clear clinical outcomes; side-effect differences reported.

Study Details

PMID:35212136
Participants:120
Impact:zinc 93.4% vs PPD 83.3% (no significant difference)
Trust score:4/5

number of sessions to cure

1 evidences

Randomized trial in children comparing intralesional zinc sulfate 2% vs PPD for warts; both effective, zinc had faster injected-wart clearance but more complications.

Trust comment: Randomized clinical trial with adequate sample size and clear clinical outcomes; side-effect differences reported.

Study Details

PMID:35212136
Participants:120
Impact:zinc median 3 sessions vs PPD 4 sessions
Trust score:4/5

treatment complications (pain, inflammation, necrosis, scar)

1 evidences

Randomized trial in children comparing intralesional zinc sulfate 2% vs PPD for warts; both effective, zinc had faster injected-wart clearance but more complications.

Trust comment: Randomized clinical trial with adequate sample size and clear clinical outcomes; side-effect differences reported.

Study Details

PMID:35212136
Participants:120
Impact:higher in zinc group (statistically significant)
Trust score:4/5

recurrence rate

1 evidences

Randomized trial in children comparing intralesional zinc sulfate 2% vs PPD for warts; both effective, zinc had faster injected-wart clearance but more complications.

Trust comment: Randomized clinical trial with adequate sample size and clear clinical outcomes; side-effect differences reported.

Study Details

PMID:35212136
Participants:120
Impact:higher in zinc group (non-significant)
Trust score:4/5

folic acid response

1 evidences

Study in pregnant adolescents showing zinc supplementation prevented decline in plasma zinc and enhanced folic acid response when given together.

Trust comment: Moderate-sized human supplementation study but older, group allocation method unclear and outcomes biochemical rather than clinical.

Study Details

PMID:12700794
Participants:74
Impact:larger increase when folic acid combined with zinc (suggesting zinc enhances folic acid metabolism)
Trust score:3/5

major adverse cardiovascular events (MACE)

1 evidences

Small randomized feasibility trial in AMI patients; zinc supplementation produced a non-significant reduction in infarct core zone and no reduction in MACE.

Trust comment: Randomized single-centre feasibility study but small sample and underpowered to detect clinical event differences.

Study Details

PMID:36695857
Participants:56
Impact:no significant difference between zinc and control
Trust score:3/5

scar core zone (% of infarct)

1 evidences

Small randomized feasibility trial in AMI patients; zinc supplementation produced a non-significant reduction in infarct core zone and no reduction in MACE.

Trust comment: Randomized single-centre feasibility study but small sample and underpowered to detect clinical event differences.

Study Details

PMID:36695857
Participants:56
Impact:zinc 9.3 ± 6.9% vs control 14.2 ± 9.1% (P = 0.07; numerical reduction, not statistically significant)
Trust score:3/5

Systolic blood pressure

1 evidences

In type 2 diabetics, combined minerals + vitamins (including Mg+Zn) for 3 months lowered systolic, diastolic and mean blood pressure; Mg+Zn alone did not.

Trust comment: Randomized trial but small subgroup sizes and effects are reported for combined vitamin+mineral treatment, limiting attribution specifically to zinc.

Study Details

PMID:15190052
Participants:69
Impact:decrease of 8 mmHg in vitamin+mineral group (122 ±16 vs 130 ±19 mmHg)
Trust score:3/5

Diastolic blood pressure

1 evidences

In type 2 diabetics, combined minerals + vitamins (including Mg+Zn) for 3 months lowered systolic, diastolic and mean blood pressure; Mg+Zn alone did not.

Trust comment: Randomized trial but small subgroup sizes and effects are reported for combined vitamin+mineral treatment, limiting attribution specifically to zinc.

Study Details

PMID:15190052
Participants:69
Impact:decrease of 6 mmHg in vitamin+mineral group (77 ±9 vs 83 ±11 mmHg)
Trust score:3/5

Mean blood pressure

1 evidences

In type 2 diabetics, combined minerals + vitamins (including Mg+Zn) for 3 months lowered systolic, diastolic and mean blood pressure; Mg+Zn alone did not.

Trust comment: Randomized trial but small subgroup sizes and effects are reported for combined vitamin+mineral treatment, limiting attribution specifically to zinc.

Study Details

PMID:15190052
Participants:69
Impact:decrease of 7 mmHg in vitamin+mineral group (92 ±9 vs 99 ±13 mmHg)
Trust score:3/5

serum potassium

1 evidences

In type 2 diabetics, combined minerals + vitamins (including Mg+Zn) for 3 months lowered systolic, diastolic and mean blood pressure; Mg+Zn alone did not.

Trust comment: Randomized trial but small subgroup sizes and effects are reported for combined vitamin+mineral treatment, limiting attribution specifically to zinc.

Study Details

PMID:15190052
Participants:69
Impact:increased in vitamin+mineral group (significant)
Trust score:3/5

serum malondialdehyde

1 evidences

In type 2 diabetics, combined minerals + vitamins (including Mg+Zn) for 3 months lowered systolic, diastolic and mean blood pressure; Mg+Zn alone did not.

Trust comment: Randomized trial but small subgroup sizes and effects are reported for combined vitamin+mineral treatment, limiting attribution specifically to zinc.

Study Details

PMID:15190052
Participants:69
Impact:decreased in vitamin+mineral group (significant)
Trust score:3/5

Progression to diabetes

1 evidences

6-month RCT of Lysulin (lysine, zinc, vitamin C) in pre-diabetes reduced progression to diabetes and improved glycaemic and lipid measures versus placebo.

Trust comment: Well-designed RCT with clinically meaningful endpoints, but formulation contains multiple active ingredients so effects cannot be attributed solely to zinc.

Study Details

PMID:32795739
Participants:110
Impact:reduced: control 25.4% (n=14) vs Lysulin 7.3% (n=4); P = 0.018
Trust score:3/5

2-h OGTT plasma glucose

1 evidences

6-month RCT of Lysulin (lysine, zinc, vitamin C) in pre-diabetes reduced progression to diabetes and improved glycaemic and lipid measures versus placebo.

Trust comment: Well-designed RCT with clinically meaningful endpoints, but formulation contains multiple active ingredients so effects cannot be attributed solely to zinc.

Study Details

PMID:32795739
Participants:110
Impact:significant reduction in Lysulin group (value not reported)
Trust score:3/5

plasma lipid peroxides (TBA-RS)

1 evidences

In elderly residents, 3 months of 25 mg zinc reduced a blood marker of lipid peroxidation.

Trust comment: Double-blind randomized controlled trial with 118 completers and adjusted analysis supports moderate-high reliability.

Study Details

PMID:9049568
Participants:118
Impact:decrease; adjusted β = -0.19 (95% CI -0.37, -0.002), p = 0.05
Trust score:4/5

apo A1

1 evidences

In type 2 diabetic patients, combined mineral (Mg+Zn) plus vitamins C+E increased HDL cholesterol and apolipoprotein A1 over 3 months; Mg+Zn alone showed no significant changes.

Trust comment: Randomized double-blind trial but effects reported for combined micronutrient group (Mg+Zn+vitamins), limiting attribution to zinc alone.

Study Details

PMID:15163474
Participants:69
Impact:increase by 8.8% in MV group (169.8 ± 33.8 vs 156.1 ± 23.9 mg/dl), p < 0.01
Trust score:3/5

total cholesterol, LDL-c, triglyceride, apo B

1 evidences

In type 2 diabetic patients, combined mineral (Mg+Zn) plus vitamins C+E increased HDL cholesterol and apolipoprotein A1 over 3 months; Mg+Zn alone showed no significant changes.

Trust comment: Randomized double-blind trial but effects reported for combined micronutrient group (Mg+Zn+vitamins), limiting attribution to zinc alone.

Study Details

PMID:15163474
Participants:69
Impact:no significant change in any group
Trust score:3/5

thyroid auto-antibodies (TPOAb, TgAb)

1 evidences

In children with autoimmune thyroiditis, 12 weeks of 25 mg zinc did not change autoantibodies or oxidative stress, and zinc-treated children avoided levothyroxine dose escalation seen in controls.

Trust comment: Randomized trial but open-label and small (n=40), so findings are suggestive but limited by size and design.

Study Details

PMID:38154030
Participants:40
Impact:no significant change with zinc supplementation
Trust score:3/5

oxidative stress markers

1 evidences

In children with autoimmune thyroiditis, 12 weeks of 25 mg zinc did not change autoantibodies or oxidative stress, and zinc-treated children avoided levothyroxine dose escalation seen in controls.

Trust comment: Randomized trial but open-label and small (n=40), so findings are suggestive but limited by size and design.

Study Details

PMID:38154030
Participants:40
Impact:no significant change with zinc supplementation
Trust score:3/5

levothyroxine dose requirement

1 evidences

In children with autoimmune thyroiditis, 12 weeks of 25 mg zinc did not change autoantibodies or oxidative stress, and zinc-treated children avoided levothyroxine dose escalation seen in controls.

Trust comment: Randomized trial but open-label and small (n=40), so findings are suggestive but limited by size and design.

Study Details

PMID:38154030
Participants:40
Impact:control arm showed significant dose escalation vs zinc group (p = 0.03); zinc group did not require escalation
Trust score:3/5

TLR-2 mRNA expression

1 evidences

Twelve weeks of 30 mg/day zinc reduced TLR-2 expression and improved a nonocular Behçet's disease activity score versus placebo.

Trust comment: Double-blind randomized placebo-controlled design with clear biomarker and clinical outcome changes supports moderate-high confidence.

Study Details

PMID:35413570
Participants:50
Impact:decrease vs placebo (p = 0.038)
Trust score:4/5

TLR-2 protein expression

1 evidences

Twelve weeks of 30 mg/day zinc reduced TLR-2 expression and improved a nonocular Behçet's disease activity score versus placebo.

Trust comment: Double-blind randomized placebo-controlled design with clear biomarker and clinical outcome changes supports moderate-high confidence.

Study Details

PMID:35413570
Participants:50
Impact:decrease vs placebo (p = 0.034)
Trust score:4/5

nonocular IBDDAM disease activity score

1 evidences

Twelve weeks of 30 mg/day zinc reduced TLR-2 expression and improved a nonocular Behçet's disease activity score versus placebo.

Trust comment: Double-blind randomized placebo-controlled design with clear biomarker and clinical outcome changes supports moderate-high confidence.

Study Details

PMID:35413570
Participants:50
Impact:decrease vs placebo (p = 0.046)
Trust score:4/5

First hemorrhagic stroke risk

1 evidences

Among hypertensive patients, higher baseline plasma zinc was associated with lower risk of first hemorrhagic stroke but not associated with ischemic stroke.

Trust comment: Large nested case-control (599 cases, 599 controls) with multivariable adjustment, supporting moderate-high trustworthiness for the associations reported.

Study Details

PMID:31446884
Participants:1198
Impact:Inverse association with baseline plasma zinc (significant)
Trust score:4/5

First ischemic stroke risk

1 evidences

Among hypertensive patients, higher baseline plasma zinc was associated with lower risk of first hemorrhagic stroke but not associated with ischemic stroke.

Trust comment: Large nested case-control (599 cases, 599 controls) with multivariable adjustment, supporting moderate-high trustworthiness for the associations reported.

Study Details

PMID:31446884
Participants:1198
Impact:No significant association
Trust score:4/5

Overall photodamage score

1 evidences

Topical regimen including a copper–zinc complex plus hydroquinone and tretinoin improved multiple signs of décolletage photodamage over 24 weeks.

Trust comment: Investigator-blind randomized study but small (n=42) and treatment combined multiple active agents, preventing isolation of zinc-specific effects.

Study Details

PMID:20232582
Participants:42
Impact:Significant improvement from week 4 onward
Trust score:3/5

Tactile roughness and hyperpigmentation/wrinkling

1 evidences

Topical regimen including a copper–zinc complex plus hydroquinone and tretinoin improved multiple signs of décolletage photodamage over 24 weeks.

Trust comment: Investigator-blind randomized study but small (n=42) and treatment combined multiple active agents, preventing isolation of zinc-specific effects.

Study Details

PMID:20232582
Participants:42
Impact:Significant improvements (various timepoints from week 2–12 onward)
Trust score:3/5

Hirsutism score

1 evidences

Twelve weeks of magnesium-zinc-calcium-vitamin D co-supplementation in women with PCOS reduced hirsutism and some inflammation/oxidative stress markers and increased antioxidant capacity.

Trust comment: Randomized double-blind placebo-controlled trial with clear biomarker changes, but co-supplementation prevents attribution of effects solely to zinc.

Study Details

PMID:28668998
Participants:60
Impact:-2.4 ± 1.2 vs -0.1 ± 0.4 (change)
Trust score:4/5

depression score (CES-D)

1 evidences

Women given folic-acid-containing multi-micronutrients (including zinc) for 12 weeks had lower average depressive symptoms and lower depression prevalence; no difference between weekly vs daily dosing and no baseline association between zinc and depression.

Trust comment: Large randomized trial in humans with clear outcome measures, but the intervention was a multi-micronutrient mix so effects cannot be attributed to zinc alone.

Study Details

PMID:19886513
Participants:459
Impact:-2.3 points
Trust score:4/5

depression prevalence

1 evidences

Women given folic-acid-containing multi-micronutrients (including zinc) for 12 weeks had lower average depressive symptoms and lower depression prevalence; no difference between weekly vs daily dosing and no baseline association between zinc and depression.

Trust comment: Large randomized trial in humans with clear outcome measures, but the intervention was a multi-micronutrient mix so effects cannot be attributed to zinc alone.

Study Details

PMID:19886513
Participants:459
Impact:-11.6 percentage points (49.3% → 37.7%)
Trust score:4/5

association: serum zinc vs depression

1 evidences

Women given folic-acid-containing multi-micronutrients (including zinc) for 12 weeks had lower average depressive symptoms and lower depression prevalence; no difference between weekly vs daily dosing and no baseline association between zinc and depression.

Trust comment: Large randomized trial in humans with clear outcome measures, but the intervention was a multi-micronutrient mix so effects cannot be attributed to zinc alone.

Study Details

PMID:19886513
Participants:459
Impact:no association (p>0.05)
Trust score:4/5

HOMA-IR / insulin sensitivity

1 evidences

Six weeks of magnesium-zinc-calcium-vitamin D co-supplementation in gestational diabetes improved fasting glucose, insulin-related markers and some lipid markers versus placebo.

Trust comment: Randomized double-blind trial with clear metabolic endpoints, but zinc was given as part of a multi-nutrient supplement so individual zinc effects are not isolated.

Study Details

PMID:29316405
Participants:60
Impact:HOMA-IR -1.0 ±1.1 vs +0.3 ±1.3 (P<0.001); QUICKI +0.02 ±0.03 vs -0.002 ±0.03 (P=0.003)
Trust score:4/5

triglycerides and VLDL

1 evidences

Six weeks of magnesium-zinc-calcium-vitamin D co-supplementation in gestational diabetes improved fasting glucose, insulin-related markers and some lipid markers versus placebo.

Trust comment: Randomized double-blind trial with clear metabolic endpoints, but zinc was given as part of a multi-nutrient supplement so individual zinc effects are not isolated.

Study Details

PMID:29316405
Participants:60
Impact:triglycerides -0.25 ±0.10 mmol/L vs +0.34 ±0.10 (P=0.001); VLDL -0.11 ±0.04 vs +0.15 ±0.04 (P=0.001)
Trust score:4/5

hypozincemia prevalence

1 evidences

Compared quintuply-fortified salt (including iodine) versus iodized salt in nonpregnant reproductive-age women; QFS improved several micronutrient deficiencies versus iodized salt.

Trust comment: Large, double-blind, randomized community trial with objective biomarker outcomes showing direct improvement in zinc status from fortified salt.

Study Details

PMID:40610127
Participants:998
Impact:OR 0.62 at 6 months (38% lower odds vs iodized salt; 95% CI: 0.41–0.93)
Trust score:5/5

vitamin B12 insufficiency

1 evidences

Compared quintuply-fortified salt (including iodine) versus iodized salt in nonpregnant reproductive-age women; QFS improved several micronutrient deficiencies versus iodized salt.

Trust comment: Large, double-blind, randomized community trial with objective biomarker outcomes showing direct improvement in zinc status from fortified salt.

Study Details

PMID:40610127
Participants:998
Impact:OR 0.20 at 6 months (80% lower odds; 95% CI: 0.13–0.31)
Trust score:5/5

folate insufficiency

1 evidences

Compared quintuply-fortified salt (including iodine) versus iodized salt in nonpregnant reproductive-age women; QFS improved several micronutrient deficiencies versus iodized salt.

Trust comment: Large, double-blind, randomized community trial with objective biomarker outcomes showing direct improvement in zinc status from fortified salt.

Study Details

PMID:40610127
Participants:998
Impact:OR 0.14 at 6 months (86% lower odds; 95% CI: 0.09–0.21)
Trust score:5/5

Night sleep duration

1 evidences

In two large randomized trials, daily iron-folic acid with or without zinc for 12 months was associated with longer night and total sleep duration and reduced night waking in infants; zinc supplementation also contributed to longer sleep.

Trust comment: Large randomized, placebo-controlled trials with consistent maternal-reported sleep benefits, though some effects are reported for iron and combined supplements as well as zinc.

Study Details

PMID:19322104
Participants:1444
Impact:increase (maternal report; exact values not reported)
Trust score:4/5

total sleep duration

1 evidences

In two large randomized trials, daily iron-folic acid with or without zinc for 12 months was associated with longer night and total sleep duration and reduced night waking in infants; zinc supplementation also contributed to longer sleep.

Trust comment: Large randomized, placebo-controlled trials with consistent maternal-reported sleep benefits, though some effects are reported for iron and combined supplements as well as zinc.

Study Details

PMID:19322104
Participants:1444
Impact:increase (maternal report)
Trust score:4/5

night waking frequency

1 evidences

In two large randomized trials, daily iron-folic acid with or without zinc for 12 months was associated with longer night and total sleep duration and reduced night waking in infants; zinc supplementation also contributed to longer sleep.

Trust comment: Large randomized, placebo-controlled trials with consistent maternal-reported sleep benefits, though some effects are reported for iron and combined supplements as well as zinc.

Study Details

PMID:19322104
Participants:1444
Impact:decrease (maternal report)
Trust score:4/5

TGF-β1

1 evidences

In 12–24-month-old children, the small zinc-only arm showed a significant increase in TGF-β1 and greater body-weight gain over 90 days; probiotic and combined arms affected sIgA and cytokine correlations.

Trust comment: Randomized placebo-controlled trial but very small zinc arm (n=8) limits precision and generalizability.

Study Details

PMID:30694099
Participants:38
Impact:significant increase in zinc group vs placebo (P=0.05)
Trust score:3/5

percentage of days with diarrhea / diarrhea prevalence

1 evidences

Randomized trial in children 6–24 months found no reduction in diarrhea or respiratory morbidity from zinc or zinc-plus-multiple-micronutrient supplements (the multiple micronutrient tablet contained 50 µg iodine).

Trust comment: Well-conducted randomized, double-blind trial with weekly surveillance and intention-to-treat analysis showing no prophylactic effect of zinc on diarrheal or respiratory morbidity in this setting.

Study Details

PMID:17593956
Participants:335
Impact:no significant change between zinc/micronutrient and control groups
Trust score:4/5

upper respiratory symptoms / pneumonia

1 evidences

Randomized trial in children 6–24 months found no reduction in diarrhea or respiratory morbidity from zinc or zinc-plus-multiple-micronutrient supplements (the multiple micronutrient tablet contained 50 µg iodine).

Trust comment: Well-conducted randomized, double-blind trial with weekly surveillance and intention-to-treat analysis showing no prophylactic effect of zinc on diarrheal or respiratory morbidity in this setting.

Study Details

PMID:17593956
Participants:335
Impact:no significant change between zinc/micronutrient and control groups
Trust score:4/5

anaemia prevalence (Hb < 10.5 g/dL)

1 evidences

Children (9–11 mo) given daily MNPs containing zinc and iron for 24 weeks had lower anaemia than at baseline, but many remained anaemic; socioeconomic, hygiene and morbidity factors predicted anaemia at endline.

Trust comment: Large randomized trial with high adherence and repeated hemoglobin measures, but secondary analysis and hemoglobin measured by capillary HemoCue limit gold-standard biomarker certainty.

Study Details

PMID:39925177
Participants:442
Impact:endline prevalence 32.6%; ~18 percentage-point reduction from baseline in the standard MNP group
Trust score:4/5

iron deficiency anaemia (subset biomarkers)

1 evidences

Children (9–11 mo) given daily MNPs containing zinc and iron for 24 weeks had lower anaemia than at baseline, but many remained anaemic; socioeconomic, hygiene and morbidity factors predicted anaemia at endline.

Trust comment: Large randomized trial with high adherence and repeated hemoglobin measures, but secondary analysis and hemoglobin measured by capillary HemoCue limit gold-standard biomarker certainty.

Study Details

PMID:39925177
Participants:442
Impact:subset (n=58) IDA prevalence decreased from 47% at baseline to 16% at endline (−31 percentage points)
Trust score:4/5

ORS + zinc uptake

1 evidences

A community social franchising program markedly increased household use of ORS plus zinc for childhood diarrhea compared with standard access.

Trust comment: Community-level randomized controlled design with large sample and clear, programmatic outcome; outcome measured at one-year follow-up.

Study Details

PMID:24401752
Participants:3605
Impact:intervention 13.7% vs control 1.8% (difference +11.9 percentage points; p < 0.001)
Trust score:4/5

depressive symptom reduction (treatment‑resistant subgroup)

1 evidences

In depressed patients on imipramine, adding zinc (25 mg/day) improved depressive symptoms and speed of response in those who were treatment-resistant, but not in treatment‑responsive patients.

Trust comment: Double-blind randomized trial but small overall sample and subgroup effect limits generalizability; exact effect sizes not provided in the excerpt.

Study Details

PMID:19278731
Participants:60
Impact:significant improvement with zinc augmentation versus placebo (reported by authors; subgroup effect)
Trust score:3/5

no effect in non-resistant patients

1 evidences

In depressed patients on imipramine, adding zinc (25 mg/day) improved depressive symptoms and speed of response in those who were treatment-resistant, but not in treatment‑responsive patients.

Trust comment: Double-blind randomized trial but small overall sample and subgroup effect limits generalizability; exact effect sizes not provided in the excerpt.

Study Details

PMID:19278731
Participants:60
Impact:no significant difference between zinc and placebo in antidepressant‑responsive patients
Trust score:3/5

early child development (motor, cognitive/language, socioemotional)

1 evidences

In this cohort of children whose mothers were randomized prenatally, randomized prenatal zinc showed no significant effect on motor, cognitive/language, or socioemotional development at 20–39 months.

Trust comment: Follow-up of an RCT cohort with standardized developmental assessments but modest sample size and possible limited power to detect small effects.

Study Details

PMID:30124230
Participants:198
Impact:no significant effect of randomized prenatal zinc on any development domain
Trust score:3/5

severe diarrhea risk

1 evidences

Weekly simultaneous iron + zinc supplementation reduced severe diarrhea and, in undernourished infants, reduced severe ALRI compared with control.

Trust comment: Double-blind, randomized community trial with biological measures and morbidity outcomes; subgroup effects in undernourished children should be interpreted cautiously.

Study Details

PMID:14652364
Participants:799
Impact:iron + zinc: 19% lower risk in all infants; 30% lower risk in less well‑nourished infants
Trust score:4/5

severe ALRI risk (less well‑nourished)

1 evidences

Weekly simultaneous iron + zinc supplementation reduced severe diarrhea and, in undernourished infants, reduced severe ALRI compared with control.

Trust comment: Double-blind, randomized community trial with biological measures and morbidity outcomes; subgroup effects in undernourished children should be interpreted cautiously.

Study Details

PMID:14652364
Participants:799
Impact:iron + zinc: 40% lower risk in less well‑nourished infants
Trust score:4/5

recipe acceptability / child intake

1 evidences

In a pilot randomized crossover acceptability study, recipes made with biofortified crops (including high‑zinc varieties) were consumed similarly and rated as acceptable by mothers compared with control crops.

Trust comment: Randomized crossover design is robust for acceptability but small pilot sample and single-meal feedings limit generalizability to longer-term consumption.

Study Details

PMID:31359782
Participants:52
Impact:no significant differences in children's intake between biofortified and control varieties for any recipe
Trust score:3/5

mother hedonic acceptability

1 evidences

In a pilot randomized crossover acceptability study, recipes made with biofortified crops (including high‑zinc varieties) were consumed similarly and rated as acceptable by mothers compared with control crops.

Trust comment: Randomized crossover design is robust for acceptability but small pilot sample and single-meal feedings limit generalizability to longer-term consumption.

Study Details

PMID:31359782
Participants:52
Impact:no significant differences in overall acceptability ratings between biofortified and control varieties
Trust score:3/5

infectious event frequency

1 evidences

Elderly institutionalized subjects receiving trace elements (including zinc 20 mg daily) alone or with vitamins had fewer infectious events over two years compared with placebo.

Trust comment: Double-blind controlled design but small institutionalized sample and combined trace element intervention (zinc + selenium) make it harder to isolate zinc-specific effects.

Study Details

PMID:9267584
Participants:81
Impact:subjects receiving zinc (with selenium) had significantly fewer infections during 2 years compared with placebo
Trust score:3/5

serum zinc correction

1 evidences

Elderly institutionalized subjects receiving trace elements (including zinc 20 mg daily) alone or with vitamins had fewer infectious events over two years compared with placebo.

Trust comment: Double-blind controlled design but small institutionalized sample and combined trace element intervention (zinc + selenium) make it harder to isolate zinc-specific effects.

Study Details

PMID:9267584
Participants:81
Impact:serum zinc levels increased and plateaued after 6 months in supplemented groups
Trust score:3/5

SARS‑CoV‑2 viral load (RdRp CT)

1 evidences

Randomized open-label trial in asymptomatic COVID-19 patients comparing KSK decoction to standard care (vitamin C + zinc) for 7 days; measured viral load and cytokines.

Trust comment: Randomized controlled trial with objective viral outcome but small sample and open‑label design limit certainty.

Study Details

PMID:34526104
Participants:60
Impact:+3.81 Ct mean increase (29.63 → 33.45) in KSK arm vs +2.60 Ct in control (greater Ct = lower viral load)
Trust score:3/5

progression to symptomatic disease

1 evidences

Randomized open-label trial in asymptomatic COVID-19 patients comparing KSK decoction to standard care (vitamin C + zinc) for 7 days; measured viral load and cytokines.

Trust comment: Randomized controlled trial with objective viral outcome but small sample and open‑label design limit certainty.

Study Details

PMID:34526104
Participants:60
Impact:No participants progressed to symptomatic in either group (0 cases)
Trust score:3/5

IL‑6 (subset with elevated baseline)

1 evidences

Randomized open-label trial in asymptomatic COVID-19 patients comparing KSK decoction to standard care (vitamin C + zinc) for 7 days; measured viral load and cytokines.

Trust comment: Randomized controlled trial with objective viral outcome but small sample and open‑label design limit certainty.

Study Details

PMID:34526104
Participants:60
Impact:Elevated IL‑6 in subset fell from mean 107.20 pg/mL (baseline subset) to ~14.35 pg/mL in remaining elevated cases at day 7
Trust score:3/5

Montenegro skin test response

1 evidences

Cross-sectional analysis of serum copper, selenium and zinc versus Montenegro skin test (MST) diameter in vaccinated volunteers.

Trust comment: Moderate-quality observational study (n=172) with appropriate assays but correlational design cannot establish causality.

Study Details

PMID:17980395
Participants:172
Impact:MST diameter associated with selenium levels only; no significant association reported for serum zinc
Trust score:3/5

Ponderal and linear growth / IGF‑I and markers

1 evidences

Double-blind randomized trial of three oral zinc regimens in severely malnourished children during 90 days of nutritional rehabilitation, measuring growth, IGF‑I axis and bone/collagen markers.

Trust comment: Well-conducted double-blind randomized intervention with repeated measures in 141 children; results robust for comparison of zinc regimens.

Study Details

PMID:12201833
Participants:141
Impact:No differences among zinc regimens in growth, IGF‑I, IGFBP or bone/collagen turnover markers (null effect of regimen)
Trust score:4/5

Markers of bone/collagen turnover during refeeding

1 evidences

Double-blind randomized trial of three oral zinc regimens in severely malnourished children during 90 days of nutritional rehabilitation, measuring growth, IGF‑I axis and bone/collagen markers.

Trust comment: Well-conducted double-blind randomized intervention with repeated measures in 141 children; results robust for comparison of zinc regimens.

Study Details

PMID:12201833
Participants:141
Impact:IGF‑I, IGFBP3, BAP, PICP and P3NP increased during refeeding (all P<0.001) — independent of zinc regimen
Trust score:4/5

Amount consumed (acceptability)

1 evidences

Randomized crossover acceptability study in 6–24 month-old children comparing a common‑bean+pumpkin blend (higher iron/zinc) to pumpkin control; measured intake and micronutrient intake.

Trust comment: Randomized crossover design with objective intake measures in 70 children; small sample but methods appropriate for acceptability outcomes.

Study Details

PMID:32873263
Participants:70
Impact:No significant difference; BPB 53.9 ± 2.97 g vs PB 54.4 ± 3.51 g (both ≥50 g, 100% acceptable)
Trust score:4/5

Zinc intake from serving

1 evidences

Randomized crossover acceptability study in 6–24 month-old children comparing a common‑bean+pumpkin blend (higher iron/zinc) to pumpkin control; measured intake and micronutrient intake.

Trust comment: Randomized crossover design with objective intake measures in 70 children; small sample but methods appropriate for acceptability outcomes.

Study Details

PMID:32873263
Participants:70
Impact:+0.45 mg (BPB 0.58 ± 0.04 mg vs PB 0.13 ± 0.01 mg; p<0.00001)
Trust score:4/5

Iron intake from serving

1 evidences

Randomized crossover acceptability study in 6–24 month-old children comparing a common‑bean+pumpkin blend (higher iron/zinc) to pumpkin control; measured intake and micronutrient intake.

Trust comment: Randomized crossover design with objective intake measures in 70 children; small sample but methods appropriate for acceptability outcomes.

Study Details

PMID:32873263
Participants:70
Impact:+0.8 mg (BPB 1.1 ± 0.59 mg vs PB 0.3 ± 0.02 mg; p<0.00001)
Trust score:4/5

Fractional absorption of zinc (FAZ)

1 evidences

Double-blind randomized crossover trial in Gambian children measuring fractional and total zinc absorption from porridge with SQ‑LNS with vs without added phytase using isotopic tracers.

Trust comment: High-quality double-blind crossover RCT using isotope tracers and objective endpoints, though small (n=26 completed).

Study Details

PMID:31504101
Participants:26
Impact:FAZ increased from 8.6% to 16.0% with phytase (+7.4 percentage points; P<0.001)
Trust score:5/5

Linear growth in stunted children

1 evidences

Large double-blind randomized community trial in South Africa comparing vitamin A, vitamin A+zinc, and multiple micronutrients (including zinc) with longitudinal growth and anemia outcomes over 18 months.

Trust comment: Large, double-blind randomized trial with long follow-up and stratified analyses; exploratory subgroup analyses should be interpreted cautiously.

Study Details

PMID:20298571
Participants:317
Impact:Multiple micronutrients arm: +0.7 LAZ over 18 months vs declines of -0.3 (vitamin A+zinc) and -0.2 (vitamin A)
Trust score:5/5

Effect of zinc alone (vitamin A+zinc) on growth

1 evidences

Large double-blind randomized community trial in South Africa comparing vitamin A, vitamin A+zinc, and multiple micronutrients (including zinc) with longitudinal growth and anemia outcomes over 18 months.

Trust comment: Large, double-blind randomized trial with long follow-up and stratified analyses; exploratory subgroup analyses should be interpreted cautiously.

Study Details

PMID:20298571
Participants:317
Impact:No observable improvement in longitudinal length‑for‑age Z scores in non‑stunted children; zinc alone did not improve growth in the overall sample
Trust score:5/5

Anemia / hemoglobin (exploratory)

1 evidences

Large double-blind randomized community trial in South Africa comparing vitamin A, vitamin A+zinc, and multiple micronutrients (including zinc) with longitudinal growth and anemia outcomes over 18 months.

Trust comment: Large, double-blind randomized trial with long follow-up and stratified analyses; exploratory subgroup analyses should be interpreted cautiously.

Study Details

PMID:20298571
Participants:317
Impact:Multiple micronutrients reduced anemia prevalence more than other arms over 12 months (within-arm reductions significant), zinc+vitamin A showed smaller hemoglobin increase
Trust score:5/5

Histopathology‑positive placental malaria risk

1 evidences

Large randomized double-blind placebo-controlled factorial trial in pregnant women assessing daily vitamin A and/or zinc from first trimester to delivery with placental malaria and birth outcomes.

Trust comment: Large, well-conducted double-blind placebo-controlled RCT (2,500 randomized; birth outcomes available for 2,434) with objective histopathology outcome.

Study Details

PMID:28115667
Participants:2434
Impact:Zinc recipients had ~36% lower risk (risk ratio = 0.64; 95% CI 0.44–0.91) compared with non‑zinc recipients
Trust score:5/5

PCR‑positive malaria, SGA, prematurity

1 evidences

Large randomized double-blind placebo-controlled factorial trial in pregnant women assessing daily vitamin A and/or zinc from first trimester to delivery with placental malaria and birth outcomes.

Trust comment: Large, well-conducted double-blind placebo-controlled RCT (2,500 randomized; birth outcomes available for 2,434) with objective histopathology outcome.

Study Details

PMID:28115667
Participants:2434
Impact:No effect of zinc (or vitamin A) on PCR‑positive malaria, small‑for‑gestational‑age births, or prematurity (no change)
Trust score:5/5

infant plasma zinc

1 evidences

Mothers took zinc during pregnancy and postpartum; their infants had lower plasma zinc but slightly higher IL-7 and hepatitis B antibody responses.

Trust comment: Randomized double-blind placebo-controlled trial but small sample and some effects only marginally significant.

Study Details

PMID:26208687
Participants:39
Impact:decreased (p<0.05)
Trust score:4/5

infant IL-7

1 evidences

Mothers took zinc during pregnancy and postpartum; their infants had lower plasma zinc but slightly higher IL-7 and hepatitis B antibody responses.

Trust comment: Randomized double-blind placebo-controlled trial but small sample and some effects only marginally significant.

Study Details

PMID:26208687
Participants:39
Impact:marginal increase (p<0.10)
Trust score:4/5

hepatitis B vaccine antibody response

1 evidences

Mothers took zinc during pregnancy and postpartum; their infants had lower plasma zinc but slightly higher IL-7 and hepatitis B antibody responses.

Trust comment: Randomized double-blind placebo-controlled trial but small sample and some effects only marginally significant.

Study Details

PMID:26208687
Participants:39
Impact:marginal increase (p<0.10)
Trust score:4/5

progression to advanced AMD

1 evidences

Reanalyses of AREDS data found no reproducible interaction between CFH/ARMS2 genotype and response to antioxidant plus zinc supplementation for AMD progression.

Trust comment: Large reanalysis of existing trial data with multiple independent teams; thorough but limited to available AREDS data.

Study Details

PMID:29032853
Participants:879
Impact:supplement benefit not dependent on CFH/ARMS2 genotype (no reproducible interaction)
Trust score:4/5

erythrocyte magnesium

1 evidences

Measured plasma and erythrocyte minerals in hospitalized patients on antipsychotics; erythrocyte magnesium decreased whereas plasma magnesium was unchanged; no clear plasma zinc change reported.

Trust comment: Clinical observational measurement in a modest sample; informative but limited by size and clinical heterogeneity.

Study Details

PMID:15466963
Participants:56
Impact:decreased (p<0.01)
Trust score:3/5

plasma magnesium

1 evidences

Measured plasma and erythrocyte minerals in hospitalized patients on antipsychotics; erythrocyte magnesium decreased whereas plasma magnesium was unchanged; no clear plasma zinc change reported.

Trust comment: Clinical observational measurement in a modest sample; informative but limited by size and clinical heterogeneity.

Study Details

PMID:15466963
Participants:56
Impact:no change
Trust score:3/5

cellular zinc

1 evidences

A multivitamin-mineral supplement containing zinc increased serum and cellular zinc and showed signals of improved mitochondrial function and antioxidant enzyme activity in healthy volunteers.

Trust comment: Randomized placebo-controlled design but intervention was a multinutrient formula so effects cannot be attributed to zinc alone.

Study Details

PMID:28171220
Participants:150
Impact:increased at 3 and 6 months (p<0.001)
Trust score:3/5

mitochondrial activity

1 evidences

A multivitamin-mineral supplement containing zinc increased serum and cellular zinc and showed signals of improved mitochondrial function and antioxidant enzyme activity in healthy volunteers.

Trust comment: Randomized placebo-controlled design but intervention was a multinutrient formula so effects cannot be attributed to zinc alone.

Study Details

PMID:28171220
Participants:150
Impact:increased (trend p=0.087)
Trust score:3/5

systemic inflammation (CRP, pentraxin 3, IFN-γ, MDA)

1 evidences

Perioperative zinc plus vitamin E supplementation increased plasma zinc, reduced inflammatory markers, and shortened hospital length of stay after CABG surgery.

Trust comment: Randomized double-blind trial with clear clinical and biomarker outcomes, but supplementation combined zinc with vitamin E.

Study Details

PMID:37891226
Participants:78
Impact:decreased (various p<0.05 to p<0.0001)
Trust score:4/5

serum zinc status

1 evidences

Reducing phytate in weaning cereals produced little long-term effect on infants' iron or zinc status over 6 months.

Trust comment: Large randomized intervention with good follow-up, but effects on zinc status were minimal.

Study Details

PMID:12816787
Participants:267
Impact:no significant improvement with phytate-reduced cereals
Trust score:4/5

bleeding index

1 evidences

Brushing with an herbal toothpaste containing zinc for 6 months reduced plaque, gingival inflammation, and bleeding more than a fluoride-only toothpaste.

Trust comment: Randomized clinical trial with reasonable completion rate and clear reported outcomes, though formulations included multiple herbal ingredients alongside zinc.

Study Details

PMID:33866666
Participants:150
Impact:-73.3%
Trust score:4/5

falciparum malaria incidence

1 evidences

Zinc supplementation had no effect on falciparum malaria incidence but reduced diarrhoea prevalence; mortality was lower numerically but not statistically significant.

Trust comment: Well-conducted randomized, double-blind placebo trial with high completion rate; reported clear primary and secondary outcomes.

Study Details

PMID:11431296
Participants:685
Impact:-2% (RR 0.98; no significant difference)
Trust score:4/5

diarrhoea prevalence

1 evidences

Zinc supplementation had no effect on falciparum malaria incidence but reduced diarrhoea prevalence; mortality was lower numerically but not statistically significant.

Trust comment: Well-conducted randomized, double-blind placebo trial with high completion rate; reported clear primary and secondary outcomes.

Study Details

PMID:11431296
Participants:685
Impact:-13% (RR 0.87)
Trust score:4/5

Ascaris lumbricoides incidence

1 evidences

Zinc (alone or combined with vitamin A) produced parasite-specific effects: zinc alone increased Ascaris incidence but reduced durations of Giardia infections and reduced E. histolytica–associated diarrhea.

Trust comment: Randomized, double-blind, placebo-controlled trial with detailed parasite-specific outcomes, though effects varied by parasite and supplement combination.

Study Details

PMID:17908741
Participants:707
Impact:increased (zinc alone)
Trust score:4/5

Giardia lamblia infection duration

1 evidences

Zinc (alone or combined with vitamin A) produced parasite-specific effects: zinc alone increased Ascaris incidence but reduced durations of Giardia infections and reduced E. histolytica–associated diarrhea.

Trust comment: Randomized, double-blind, placebo-controlled trial with detailed parasite-specific outcomes, though effects varied by parasite and supplement combination.

Study Details

PMID:17908741
Participants:707
Impact:reduced (zinc and combination arms)
Trust score:4/5

Entamoeba histolytica–associated diarrheal episodes

1 evidences

Zinc (alone or combined with vitamin A) produced parasite-specific effects: zinc alone increased Ascaris incidence but reduced durations of Giardia infections and reduced E. histolytica–associated diarrhea.

Trust comment: Randomized, double-blind, placebo-controlled trial with detailed parasite-specific outcomes, though effects varied by parasite and supplement combination.

Study Details

PMID:17908741
Participants:707
Impact:reduced (zinc alone)
Trust score:4/5

microalbuminuria

1 evidences

Maternal supplementation including a folic acid+iron+zinc arm reduced children's risk of microalbuminuria but had no clear effect on most metabolic markers; metabolic syndrome reduction was seen only in the folic acid alone group.

Trust comment: Large sector-randomized trial with long-term follow-up and objective outcomes, though zinc was part of combination supplements limiting isolate effects.

Study Details

PMID:19549749
Participants:3524
Impact:-47% (OR 0.53 in folic acid+iron+zinc group)
Trust score:4/5

metabolic syndrome

1 evidences

Maternal supplementation including a folic acid+iron+zinc arm reduced children's risk of microalbuminuria but had no clear effect on most metabolic markers; metabolic syndrome reduction was seen only in the folic acid alone group.

Trust comment: Large sector-randomized trial with long-term follow-up and objective outcomes, though zinc was part of combination supplements limiting isolate effects.

Study Details

PMID:19549749
Participants:3524
Impact:no significant change from folic acid+iron+zinc (reduction seen only in folic acid alone: OR 0.63)
Trust score:4/5

carotid plaque prevalence

1 evidences

Long-term low-dose combined antioxidant supplementation (including 120 mg vitamin C) showed no benefit on carotid intima-media thickness or arterial stiffness and had a higher proportion of carotid plaques in the intervention group.

Trust comment: Substudy of a large randomized double-blind trial including zinc within a multi-nutrient mix; good design but zinc effects cannot be isolated.

Study Details

PMID:15217803
Participants:1162
Impact:Intervention 35.2% vs placebo 29.5% (P=0.04) — higher plaque prevalence in supplement group
Trust score:3/5

common carotid intima-media thickness (IMT)

1 evidences

Long-term low-dose combined antioxidant supplementation (including 120 mg vitamin C) showed no benefit on carotid intima-media thickness or arterial stiffness and had a higher proportion of carotid plaques in the intervention group.

Trust comment: Substudy of a large randomized double-blind trial including zinc within a multi-nutrient mix; good design but zinc effects cannot be isolated.

Study Details

PMID:15217803
Participants:1162
Impact:No difference (0.70±0.08 mm vs 0.70±0.08 mm, P=0.38)
Trust score:3/5

aortic stiffness (PWV)

1 evidences

Long-term low-dose combined antioxidant supplementation (including 120 mg vitamin C) showed no benefit on carotid intima-media thickness or arterial stiffness and had a higher proportion of carotid plaques in the intervention group.

Trust comment: Substudy of a large randomized double-blind trial including zinc within a multi-nutrient mix; good design but zinc effects cannot be isolated.

Study Details

PMID:15217803
Participants:1162
Impact:Trend toward lower PWV in intervention group but not significant (P=0.13)
Trust score:3/5

humoral response to influenza vaccine

1 evidences

In institutionalized elderly, daily low‑dose supplements (including ascorbic acid in the vitamin arm) corrected deficiencies but vitamins did not improve cell‑mediated immunity and the vitamin arm had lower influenza antibody titers; trace elements improved antibody response.

Trust comment: Large randomized double-blind placebo-controlled factorial trial in elderly with clinical endpoints and sustained supplementation, though effects combine zinc with selenium.

Study Details

PMID:10218756
Participants:725
Impact:Higher antibody titers in groups receiving trace elements (zinc+selenium) (P<0.05)
Trust score:4/5

respiratory tract infections

1 evidences

In institutionalized elderly, daily low‑dose supplements (including ascorbic acid in the vitamin arm) corrected deficiencies but vitamins did not improve cell‑mediated immunity and the vitamin arm had lower influenza antibody titers; trace elements improved antibody response.

Trust comment: Large randomized double-blind placebo-controlled factorial trial in elderly with clinical endpoints and sustained supplementation, though effects combine zinc with selenium.

Study Details

PMID:10218756
Participants:725
Impact:More patients without respiratory infections in trace element groups (P=0.06, trend)
Trust score:4/5

overall survival

1 evidences

In institutionalized elderly, daily low‑dose supplements (including ascorbic acid in the vitamin arm) corrected deficiencies but vitamins did not improve cell‑mediated immunity and the vitamin arm had lower influenza antibody titers; trace elements improved antibody response.

Trust comment: Large randomized double-blind placebo-controlled factorial trial in elderly with clinical endpoints and sustained supplementation, though effects combine zinc with selenium.

Study Details

PMID:10218756
Participants:725
Impact:No difference in 2-year survival between groups
Trust score:4/5

inflammatory markers (IL-1β, IL-6, TNF-α, CRP)

1 evidences

48 postmenopausal women with type 2 diabetes received zinc (40 mg/day) ± ALA or placebo for 12 weeks; zinc raised plasma zinc but did not change inflammatory marker concentrations.

Trust comment: Randomized double-blind placebo-controlled trial with clearly reported endpoints but modest sample size and specialized population.

Study Details

PMID:23643522
Participants:48
Impact:no significant change
Trust score:4/5

SOD gene expression and activity

1 evidences

70 overweight adults with T2DM took 50 mg zinc gluconate daily for 8 weeks; zinc increased SOD expression/activity and improved glycemic and some lipid parameters.

Trust comment: Randomized double-blind placebo-controlled trial with clear biochemical outcomes; moderate sample size.

Study Details

PMID:31129183
Participants:70
Impact:increased (p < 0.01)
Trust score:4/5

glycemic control (FBG, HbA1c, HOMA-IR)

1 evidences

70 overweight adults with T2DM took 50 mg zinc gluconate daily for 8 weeks; zinc increased SOD expression/activity and improved glycemic and some lipid parameters.

Trust comment: Randomized double-blind placebo-controlled trial with clear biochemical outcomes; moderate sample size.

Study Details

PMID:31129183
Participants:70
Impact:reduced (p < 0.001)
Trust score:4/5

insulin and lipid levels

1 evidences

70 overweight adults with T2DM took 50 mg zinc gluconate daily for 8 weeks; zinc increased SOD expression/activity and improved glycemic and some lipid parameters.

Trust comment: Randomized double-blind placebo-controlled trial with clear biochemical outcomes; moderate sample size.

Study Details

PMID:31129183
Participants:70
Impact:insulin increased (p = 0.02); triglycerides and total cholesterol reduced (p < 0.05)
Trust score:4/5

weight-for-height z score (WHZ)

2 evidences

In undernourished children, glutamine improved weight-for-height (WHZ) and intestinal barrier; adding zinc and vitamin A produced small, non-significant additional growth benefit and did not change leptin/IGF-1/adiponectin/cortisol levels.

Trust comment: Randomized, double-blind, community trial with pre-specified biochemical and anthropometric endpoints; zinc was given only as part of combination so zinc-alone effects are unclear.

Study Details

PMID:24714829
Participants:314
Impact:glutamine: +0.26±0.02 vs placebo -0.08±0.01 (p=0.03); glutamine+zinc+vitA: +0.096±0.05 (p=0.277, NS)
Trust score:4/5

2400 Tanzanian infants were randomized to zinc, multivitamins, zinc+multivitamins, or placebo from 6 weeks and followed 18 months; combined Zn+MV modestly reduced weight-for-age decline but zinc alone did not reduce stunting/wasting/underweight incidence.

Trust comment: Large, well-conducted randomized double-blind placebo-controlled trial with long follow-up and clinically meaningful outcomes.

Study Details

PMID:26817503
Participants:2400
Impact:greater decline in zinc-only vs placebo (−0.57 ± 0.07 vs −0.35 ± 0.07; P = 0.021)
Trust score:5/5

height-for-age z score and growth outcomes (stunting/wasting/underweight)

1 evidences

2400 Tanzanian infants were randomized to zinc, multivitamins, zinc+multivitamins, or placebo from 6 weeks and followed 18 months; combined Zn+MV modestly reduced weight-for-age decline but zinc alone did not reduce stunting/wasting/underweight incidence.

Trust comment: Large, well-conducted randomized double-blind placebo-controlled trial with long follow-up and clinically meaningful outcomes.

Study Details

PMID:26817503
Participants:2400
Impact:no significant effect on HAZ or rates of stunting, wasting, or underweight
Trust score:5/5

lactulose:mannitol ratio (L:M)

1 evidences

222 Malawian children (1–3 yr) received zinc, albendazole, or placebo; zinc prevented a significant increase in lactulose:mannitol ratio versus placebo, suggesting protection against worsening environmental enteropathy.

Trust comment: Randomized double-blind placebo-controlled trial with a reasonable sample and objective biomarker, though outcome is a surrogate for enteropathy.

Study Details

PMID:24462483
Participants:222
Impact:smaller increase in zinc group (0.03 ± 0.20) vs placebo (0.12 ± 0.31); P < .03
Trust score:4/5

zinc accumulative balance / apparent utilization

1 evidences

48 surgical patients randomized to low-dose rhGH or placebo; rhGH decreased urinary zinc excretion and improved zinc balance and utilization but raised mean blood glucose transiently postoperatively.

Trust comment: Randomized clinical setting but small surgical sample and primary intervention was growth hormone (indirect effects on zinc).

Study Details

PMID:18069770
Participants:48
Impact:improved in rhGH group (P < 0.05)
Trust score:3/5

mean blood glucose

1 evidences

48 surgical patients randomized to low-dose rhGH or placebo; rhGH decreased urinary zinc excretion and improved zinc balance and utilization but raised mean blood glucose transiently postoperatively.

Trust comment: Randomized clinical setting but small surgical sample and primary intervention was growth hormone (indirect effects on zinc).

Study Details

PMID:18069770
Participants:48
Impact:increased in rhGH group from day 3 to day 6 post-op (P < 0.05)
Trust score:3/5

sperm DNA methylation

1 evidences

Six months of daily folic acid plus zinc did not alter sperm DNA methylation compared with placebo.

Trust comment: Large, multicenter double-blind randomized trial with clear null results for the measured epigenetic outcomes.

Study Details

PMID:34656303
Participants:1470
Impact:no significant change vs placebo
Trust score:5/5

epigenetic age

1 evidences

Six months of daily folic acid plus zinc did not alter sperm DNA methylation compared with placebo.

Trust comment: Large, multicenter double-blind randomized trial with clear null results for the measured epigenetic outcomes.

Study Details

PMID:34656303
Participants:1470
Impact:no significant change vs placebo
Trust score:5/5

semen analysis parameters / live birth

1 evidences

Six months of daily folic acid plus zinc did not alter sperm DNA methylation compared with placebo.

Trust comment: Large, multicenter double-blind randomized trial with clear null results for the measured epigenetic outcomes.

Study Details

PMID:34656303
Participants:1470
Impact:no significant change (consistent with prior FAZST results)
Trust score:5/5

time to sputum smear conversion

1 evidences

Weekly zinc (with or without retinol) added to TB therapy did not improve sputum conversion, radiographic, clinical outcomes, or mortality compared with placebo.

Trust comment: Well-designed randomized, double-blind placebo-controlled trial in 350 patients, though mortality imbalance warrants cautious interpretation.

Study Details

PMID:20958890
Participants:350
Impact:no significant difference vs placebo (zinc HR 1.07; 95% CI 0.92–1.29)
Trust score:4/5

clinical/radiographic outcomes

1 evidences

Weekly zinc (with or without retinol) added to TB therapy did not improve sputum conversion, radiographic, clinical outcomes, or mortality compared with placebo.

Trust comment: Well-designed randomized, double-blind placebo-controlled trial in 350 patients, though mortality imbalance warrants cautious interpretation.

Study Details

PMID:20958890
Participants:350
Impact:no significant change at 2 or 6 months vs placebo
Trust score:4/5

prolonged diarrhea (≥7 days)

1 evidences

Daily zinc reduced the risk of prolonged diarrhea primarily in children with low cobalamin (vitamin B12) status.

Trust comment: Large, randomized double-blind trial with pre-specified subgroup biomarker analyses showing biologically plausible effect modification.

Study Details

PMID:21525251
Participants:2296
Impact:reduced in cobalamin-deficient children: OR 0.53 (95% CI 0.35–0.78) compared with OR 0.90 in higher cobalamin group (P-interaction=0.015)
Trust score:5/5

acute diarrhea

1 evidences

Daily zinc reduced the risk of prolonged diarrhea primarily in children with low cobalamin (vitamin B12) status.

Trust comment: Large, randomized double-blind trial with pre-specified subgroup biomarker analyses showing biologically plausible effect modification.

Study Details

PMID:21525251
Participants:2296
Impact:no significant effect modification by cobalamin; no clear overall effect reported here
Trust score:5/5

serum FT4

1 evidences

Ten weeks of combined zinc, vitamin A, and magnesium supplementation increased FT4 and lowered hs-CRP compared with placebo in hypothyroid patients.

Trust comment: Randomized trial but small sample and co-supplementation prevents isolating effects attributable to zinc alone.

Study Details

PMID:33409923
Participants:86
Impact:significant increase in the intervention group (P<0.05)
Trust score:3/5

anthropometric indices (weight)

1 evidences

Ten weeks of combined zinc, vitamin A, and magnesium supplementation increased FT4 and lowered hs-CRP compared with placebo in hypothyroid patients.

Trust comment: Randomized trial but small sample and co-supplementation prevents isolating effects attributable to zinc alone.

Study Details

PMID:33409923
Participants:86
Impact:decreased in intervention group (P<0.05)
Trust score:3/5

postoperative pain incidence

1 evidences

In children undergoing pulpectomy, using zinc-oxide eugenol versus Metapex did not change postoperative pain incidence.

Trust comment: Randomized clinical trial in children but small sample and study evaluates a dental material containing zinc (topical/local) rather than systemic zinc supplementation.

Study Details

PMID:36189565
Participants:80
Impact:no significant difference between zinc-oxide eugenol and Metapex (p=0.9233 single-visit; p=0.4233 multi-visit)
Trust score:3/5

post-operative sore throat incidence

1 evidences

Preoperative 40 mg zinc gargle had no consistent benefit over magnesium or budesonide; incidence and severity of postoperative sore throat were comparable across groups.

Trust comment: Well-conducted, double-blind randomized trial with adequate sample (n=180), but found no clear clinically significant benefit of zinc gargle.

Study Details

PMID:38693477
Participants:180
Impact:no significant difference vs magnesium or budesonide across timepoints; zinc showed ~10.9% lower risk vs budesonide and ~12.9% lower risk vs magnesium (reported risk reductions)
Trust score:4/5

post-operative sore throat severity

1 evidences

Preoperative 40 mg zinc gargle had no consistent benefit over magnesium or budesonide; incidence and severity of postoperative sore throat were comparable across groups.

Trust comment: Well-conducted, double-blind randomized trial with adequate sample (n=180), but found no clear clinically significant benefit of zinc gargle.

Study Details

PMID:38693477
Participants:180
Impact:comparable at all measured time points (0–24 h)
Trust score:4/5

PPD induration size

1 evidences

A single oral dose of zinc given at PPD testing increased tuberculin induration size in exposed children.

Trust comment: Randomized study in children showing a statistically significant increase in PPD induration with zinc; moderate sample and clear outcome measurement.

Study Details

PMID:12530280
Participants:98
Impact:mean +3.0 mm (zinc 18.5 mm vs placebo 15.5 mm; p<0.03)
Trust score:4/5

PPD positivity rate

1 evidences

A single oral dose of zinc given at PPD testing increased tuberculin induration size in exposed children.

Trust comment: Randomized study in children showing a statistically significant increase in PPD induration with zinc; moderate sample and clear outcome measurement.

Study Details

PMID:12530280
Participants:98
Impact:57.1% vs 53.1% (zinc vs placebo)
Trust score:4/5

association with lymphopenia

1 evidences

Most critically ill children had low serum zinc early after PICU admission and low zinc was associated with higher frequency of lymphopenia.

Trust comment: Large observational baseline dataset from a multicenter trial; shows association (not causation) between low serum zinc and lymphopenia.

Study Details

PMID:23392368
Participants:280
Impact:lymphopenia more likely with low zinc: 42.5% vs 25.6% (low vs normal/high zinc; p=0.0498)
Trust score:3/5

fasting blood glucose (FBG)

1 evidences

Daily oral zinc (40 mg) for 12 weeks improved glycemic control and markers of iron burden and renal albumin loss in β-thalassemia major patients with diabetes.

Trust comment: Randomized controlled trial with clear metabolic endpoints and significant improvements reported; moderate sample size (n=80).

Study Details

PMID:32007694
Participants:80
Impact:decreased (significant vs placebo; P < 0.05)
Trust score:4/5

insulin secretion (fasting C-peptide)

1 evidences

Daily oral zinc (40 mg) for 12 weeks improved glycemic control and markers of iron burden and renal albumin loss in β-thalassemia major patients with diabetes.

Trust comment: Randomized controlled trial with clear metabolic endpoints and significant improvements reported; moderate sample size (n=80).

Study Details

PMID:32007694
Participants:80
Impact:increased vs baseline and placebo (P < 0.05)
Trust score:4/5

insulin resistance (HOMA-IR) and glycemic markers

1 evidences

Daily oral zinc (40 mg) for 12 weeks improved glycemic control and markers of iron burden and renal albumin loss in β-thalassemia major patients with diabetes.

Trust comment: Randomized controlled trial with clear metabolic endpoints and significant improvements reported; moderate sample size (n=80).

Study Details

PMID:32007694
Participants:80
Impact:HOMA-IR and fructosamine decreased (P < 0.05)
Trust score:4/5

micronutrient intakes/status

1 evidences

Providing a daily animal-source snack for 6 months markedly reduced the prevalence of low zinc intake among women and improved several micronutrient intakes/status markers.

Trust comment: Randomized community nutrition intervention with objective intake and biomarker measures, but zinc change is from food-based intervention rather than isolated zinc supplementation.

Study Details

PMID:28424257
Participants:89
Impact:intakes of iron, vitamin A and B12 below EAR eliminated in ASF group; zinc intake deficiency markedly reduced
Trust score:3/5

hs-CRP (inflammation marker)

1 evidences

In 60 women with gestational diabetes, 6 weeks of magnesium-zinc-calcium-vitamin D reduced inflammation and oxidative stress markers and modestly lowered fasting glucose.

Trust comment: Double-blind, placebo-controlled randomized trial with clear biomarker outcomes though multi-nutrient co-supplementation limits attribution to zinc alone.

Study Details

PMID:30922259
Participants:60
Impact:−1.2 ± 3.5 mg/L vs +0.8 ± 2.0 in placebo (P = 0.01)
Trust score:4/5

total cancer incidence (women)

1 evidences

Large randomized trial of daily low-dose antioxidant supplement (included 20 mg Zn) showed lower total cancer incidence in men but not in women after 7.5 years.

Trust comment: Large, long-duration randomized trial with robust sample size but zinc was given as part of a multi-nutrient supplement so effects cannot be attributed to zinc alone.

Study Details

PMID:16115341
Participants:12741
Impact:no change
Trust score:4/5

weight/linear growth

1 evidences

Randomized double-blind trial in 100 low-birth-weight infants: daily 5 mg elemental zinc from birth to 1 year reduced diarrhea episodes and improved weight/linear growth at 1 year.

Trust comment: Well-designed randomized, double-blind, placebo-controlled community trial but relatively small sample (n=100); breastfeeding modified effects.

Study Details

PMID:14654605
Participants:100
Impact:increased (significant at 1 year)
Trust score:4/5

alopecia improvement

1 evidences

In PCOS women, 50 mg elemental zinc daily for 8 weeks improved alopecia and hirsutism scores and reduced a marker of oxidative stress (MDA), but did not change hormonal profiles.

Trust comment: Randomized double-blind placebo-controlled trial but small sample and short duration (8 weeks); outcomes well reported.

Study Details

PMID:26315303
Participants:48
Impact:41.7% vs 12.5% (zinc vs placebo; P=0.02)
Trust score:4/5

hirsutism (mFG score)

1 evidences

In PCOS women, 50 mg elemental zinc daily for 8 weeks improved alopecia and hirsutism scores and reduced a marker of oxidative stress (MDA), but did not change hormonal profiles.

Trust comment: Randomized double-blind placebo-controlled trial but small sample and short duration (8 weeks); outcomes well reported.

Study Details

PMID:26315303
Participants:48
Impact:-1.71 vs -0.29 (zinc vs placebo)
Trust score:4/5

plasma malondialdehyde (MDA)

1 evidences

In PCOS women, 50 mg elemental zinc daily for 8 weeks improved alopecia and hirsutism scores and reduced a marker of oxidative stress (MDA), but did not change hormonal profiles.

Trust comment: Randomized double-blind placebo-controlled trial but small sample and short duration (8 weeks); outcomes well reported.

Study Details

PMID:26315303
Participants:48
Impact:-0.09 μmol/L (zinc) vs +2.34 μmol/L (placebo)
Trust score:4/5

gingivitis index (GI)

1 evidences

In a 21-day crossover experimental gingivitis model, the dentifrice containing triclosan + pvm/ma + Zn + PPi reduced plaque, gingivitis, and bleeding indices versus control.

Trust comment: Double-blind crossover design but small sample and zinc was combined with multiple active ingredients (not isolated zinc effect).

Study Details

PMID:10914890
Participants:25
Impact:-35.9% vs control
Trust score:3/5

bleeding index (BI)

1 evidences

In a 21-day crossover experimental gingivitis model, the dentifrice containing triclosan + pvm/ma + Zn + PPi reduced plaque, gingivitis, and bleeding indices versus control.

Trust comment: Double-blind crossover design but small sample and zinc was combined with multiple active ingredients (not isolated zinc effect).

Study Details

PMID:10914890
Participants:25
Impact:-30.4% vs control
Trust score:3/5

iron deficiency prevalence

2 evidences

In a cluster randomized trial of young children, iron-containing micronutrient powder (which also contained 5 mg zinc) modestly improved haemoglobin and reduced anaemia and iron deficiency compared to non-iron MNP.

Trust comment: Large double-blind cluster randomized trial with intention-to-treat analysis and appropriate biomarker assessment; high confidence.

Study Details

PMID:33571267
Participants:1806
Impact:-7.19% (difference-in-difference; lower in iron group)
Trust score:5/5

Large cluster-randomized trial: daily micronutrient Sprinkles (included zinc) plus feeding education reduced anemia and iron deficiency and increased mean serum zinc during the intervention period.

Trust comment: Large cluster-randomized effectiveness trial with objective biomarker outcomes; effects on zinc and anemia did not persist beyond intervention.

Study Details

PMID:22801933
Participants:3112
Impact:-23.5% at 12 months and -11.6% at 18 months
Trust score:4/5

sputum conversion time

1 evidences

In malnourished TB patients, daily zinc (15 mg) alone or with vitamin A did not speed sputum smear conversion compared with placebo; plasma zinc rose but no clinical benefit observed.

Trust comment: Randomized double-blind trial with 300 enrolled (255 completed); well-conducted but baseline imbalances and severe malnutrition limit generalizability.

Study Details

PMID:20920186
Participants:255
Impact:no significant change vs placebo (zinc mean 3.02 wk vs placebo 2.5 wk)
Trust score:4/5

body mass index (BMI) / nutritional status

1 evidences

In malnourished TB patients, daily zinc (15 mg) alone or with vitamin A did not speed sputum smear conversion compared with placebo; plasma zinc rose but no clinical benefit observed.

Trust comment: Randomized double-blind trial with 300 enrolled (255 completed); well-conducted but baseline imbalances and severe malnutrition limit generalizability.

Study Details

PMID:20920186
Participants:255
Impact:improved during treatment across all groups (0→6 mo increases ~+1.9–2.0 kg/m²) with no zinc-specific benefit
Trust score:4/5

insulin sensitivity (M value)

1 evidences

In obese adults randomized to L-arginine vs placebo, arginine increased serum zinc and improved insulin sensitivity; changes in zinc strongly correlated with increases in insulin sensitivity.

Trust comment: Randomized double-blind trial (n=88) using gold-standard euglycemic clamp; moderate sample size and robust measures support credibility.

Study Details

PMID:23708056
Participants:88
Impact:increased in L-arginine group from 3.2 → 4.3 mg/kg/min (~+1.1) vs placebo no improvement (3.4 → 3.0); significant treatment×time interaction
Trust score:4/5

body fat percentage / BMI

1 evidences

In obese adults randomized to L-arginine vs placebo, arginine increased serum zinc and improved insulin sensitivity; changes in zinc strongly correlated with increases in insulin sensitivity.

Trust comment: Randomized double-blind trial (n=88) using gold-standard euglycemic clamp; moderate sample size and robust measures support credibility.

Study Details

PMID:23708056
Participants:88
Impact:small decrease in fat content associated with increased zinc and insulin sensitivity (inverse correlations reported)
Trust score:4/5

plasma vitamin B-12 concentration

1 evidences

In pregnant women, an MMN supplement containing 15 mg zinc produced maternal plasma zinc concentrations similar to standard iron–folic acid regimens at week 30; MMN increased vitamin B12 but did not change zinc vs controls.

Trust comment: Large randomized trial with objective biomarker measurements and adherence monitoring (n=641 samples analyzed); high reliability for the reported maternal zinc results.

Study Details

PMID:27798335
Participants:641
Impact:higher with MMN at week 30 (MMN geometric mean 119 pmol/L vs Fe60F 110 and Fe30F 101 pmol/L)
Trust score:5/5

fever incidence

1 evidences

In young Burkinabe children, adding 5 or 10 mg zinc to daily SQ-LNS or giving a 5 mg zinc tablet did not reduce diarrhoea, malaria, fever, or respiratory infections compared with SQ-LNS without added zinc.

Trust comment: Large, double-blind, cluster-randomised trial with rigorous surveillance and appropriate analyses; results directly assess zinc interventions.

Study Details

PMID:26362661
Participants:2364
Impact:no significant change
Trust score:5/5

respiratory infection prevalence (AURI/ALRI)

1 evidences

In young Burkinabe children, adding 5 or 10 mg zinc to daily SQ-LNS or giving a 5 mg zinc tablet did not reduce diarrhoea, malaria, fever, or respiratory infections compared with SQ-LNS without added zinc.

Trust comment: Large, double-blind, cluster-randomised trial with rigorous surveillance and appropriate analyses; results directly assess zinc interventions.

Study Details

PMID:26362661
Participants:2364
Impact:no significant change
Trust score:5/5

erythrocyte superoxide dismutase activity

1 evidences

In 38 cystic fibrosis patients, adding zinc to copper supplementation for 6 weeks did not change blood copper enzyme activities.

Trust comment: Small human supplementation trial showing no effect of zinc co‑supplementation on copper enzyme activities; limited by sample size and short duration.

Study Details

PMID:14681839
Participants:38
Impact:no change
Trust score:3/5

plasma diamine oxidase activity

1 evidences

In 38 cystic fibrosis patients, adding zinc to copper supplementation for 6 weeks did not change blood copper enzyme activities.

Trust comment: Small human supplementation trial showing no effect of zinc co‑supplementation on copper enzyme activities; limited by sample size and short duration.

Study Details

PMID:14681839
Participants:38
Impact:no change
Trust score:3/5

plasma ceruloplasmin activity

1 evidences

In 38 cystic fibrosis patients, adding zinc to copper supplementation for 6 weeks did not change blood copper enzyme activities.

Trust comment: Small human supplementation trial showing no effect of zinc co‑supplementation on copper enzyme activities; limited by sample size and short duration.

Study Details

PMID:14681839
Participants:38
Impact:no change
Trust score:3/5

diarrhea resolution at 72 hours

1 evidences

In young children with acute diarrhea, a hypotonic ORS containing zinc and prebiotics shortened diarrhea duration and reduced parental missed work.

Trust comment: Single-blind randomized controlled trial with clear clinical endpoints and statistically significant differences, though relatively small sample.

Study Details

PMID:20828714
Participants:119
Impact:+22.9 percentage points (72.9% vs 50%)
Trust score:4/5

ORS intake in first 24 hours

1 evidences

In young children with acute diarrhea, a hypotonic ORS containing zinc and prebiotics shortened diarrhea duration and reduced parental missed work.

Trust comment: Single-blind randomized controlled trial with clear clinical endpoints and statistically significant differences, though relatively small sample.

Study Details

PMID:20828714
Participants:119
Impact:+28 mL/kg (50 vs 22 mL/kg)
Trust score:4/5

parent missed work days

1 evidences

In young children with acute diarrhea, a hypotonic ORS containing zinc and prebiotics shortened diarrhea duration and reduced parental missed work.

Trust comment: Single-blind randomized controlled trial with clear clinical endpoints and statistically significant differences, though relatively small sample.

Study Details

PMID:20828714
Participants:119
Impact:-1.06 days (0.39 vs 1.45)
Trust score:4/5

growth (WHO z-scores)

1 evidences

Daily feeding with iron- and zinc-biofortified pearl millet did not change iron or zinc status or growth overall but raised hemoglobin in some subgroups (males and iron‑deficient children).

Trust comment: Large randomized controlled feeding trial with negative overall findings but plausible subgroup effects; well conducted.

Study Details

PMID:35299084
Participants:223
Impact:no significant change overall
Trust score:4/5

time to recovery (acute illness)

1 evidences

In moderately malnourished children with shigellosis, zinc shortens illness, promotes weight gain at recovery, and reduces diarrheal episodes over 6 months.

Trust comment: Randomized, double-blind, controlled trial with clinically meaningful outcomes in a vulnerable population; moderate sample size.

Study Details

PMID:17554249
Participants:56
Impact:median time ~50% shorter in zinc group
Trust score:4/5

weight at recovery

1 evidences

In moderately malnourished children with shigellosis, zinc shortens illness, promotes weight gain at recovery, and reduces diarrheal episodes over 6 months.

Trust comment: Randomized, double-blind, controlled trial with clinically meaningful outcomes in a vulnerable population; moderate sample size.

Study Details

PMID:17554249
Participants:56
Impact:+0.4 kg (8.8 → 9.2 kg) in zinc group
Trust score:4/5

subsequent diarrheal episodes (6 months)

1 evidences

In moderately malnourished children with shigellosis, zinc shortens illness, promotes weight gain at recovery, and reduces diarrheal episodes over 6 months.

Trust comment: Randomized, double-blind, controlled trial with clinically meaningful outcomes in a vulnerable population; moderate sample size.

Study Details

PMID:17554249
Participants:56
Impact:-1.1 episodes (2.2 vs 3.3)
Trust score:4/5

HR-HPV clearance

1 evidences

Oral zinc sulfate for 3 months increased HPV clearance and regression of cervical cytology compared to no treatment.

Trust comment: Randomized clinical trial with clear positive effects but small sample and unblinded control (no placebo), limiting certainty.

Study Details

PMID:35485687
Participants:80
Impact:+42.5 percentage points (57.5% vs 15%)
Trust score:3/5

cervical cytology regression

1 evidences

Oral zinc sulfate for 3 months increased HPV clearance and regression of cervical cytology compared to no treatment.

Trust comment: Randomized clinical trial with clear positive effects but small sample and unblinded control (no placebo), limiting certainty.

Study Details

PMID:35485687
Participants:80
Impact:+27.5 percentage points (52.5% vs 25%)
Trust score:3/5

Spn-associated ALRI risk (placebo)

1 evidences

In a nested study within a zinc prophylaxis trial, zinc appeared to remove the increased ALRI risk associated with Streptococcus pneumoniae carriage seen in placebo children.

Trust comment: Nested case-control within a community-randomized prophylaxis trial with clear comparative effects, though interaction P was borderline.

Study Details

PMID:19022973
Participants:1100
Impact:increased (adjusted matched OR = 2.57; P = 0.025)
Trust score:4/5

Spn-associated ALRI risk (zinc)

1 evidences

In a nested study within a zinc prophylaxis trial, zinc appeared to remove the increased ALRI risk associated with Streptococcus pneumoniae carriage seen in placebo children.

Trust comment: Nested case-control within a community-randomized prophylaxis trial with clear comparative effects, though interaction P was borderline.

Study Details

PMID:19022973
Participants:1100
Impact:no significant increase (adjusted matched OR = 0.95; P = 0.890); symptomatic subset: placebo AMOR = 78.09 vs zinc AMOR = 2.77
Trust score:4/5

prevalence of zinc deficiency at D180

1 evidences

Among infants with blood draws, formula with or without added MFGM showed generally similar zinc and other biomarker profiles through 24 months, with some differences versus a human milk reference group.

Trust comment: Randomized controlled trial with objective biomarker outcomes and a reasonable blood-draw subset, enabling reliable comparisons.

Study Details

PMID:36894243
Participants:243
Impact:EF -17.4% and SF -16.6% versus HM (significant differences reported)
Trust score:4/5

composite morbidity rate

1 evidences

In very-low-birth-weight preterm neonates, oral zinc supplementation reduced morbidity and mortality versus placebo, with similar weight gain.

Trust comment: Double-blind randomized controlled trial with clinically meaningful endpoints and statistically significant results.

Study Details

PMID:24025633
Participants:193
Impact:decreased (26.8% vs 41.7%; P = 0.030)
Trust score:5/5

necrotizing enterocolitis

1 evidences

In very-low-birth-weight preterm neonates, oral zinc supplementation reduced morbidity and mortality versus placebo, with similar weight gain.

Trust comment: Double-blind randomized controlled trial with clinically meaningful endpoints and statistically significant results.

Study Details

PMID:24025633
Participants:193
Impact:higher in control (6.3% vs 0%; P = 0.014)
Trust score:5/5

daily weight gain

1 evidences

In very-low-birth-weight preterm neonates, oral zinc supplementation reduced morbidity and mortality versus placebo, with similar weight gain.

Trust comment: Double-blind randomized controlled trial with clinically meaningful endpoints and statistically significant results.

Study Details

PMID:24025633
Participants:193
Impact:no difference (zinc 18.2 ± 5.6 vs control 17.0 ± 8.7 g·kg⁻¹·d⁻¹; P = 0.478)
Trust score:5/5

faecal microbiota composition

1 evidences

380 Cambodian schoolchildren ate fortified or placebo rice for 6 months; fortified rice altered gut microbiota and improved some micronutrient/inflammation markers.

Trust comment: Large double-blind cluster-RCT subsample with objective biochemical and sequencing outcomes; intervention combined multiple micronutrients so attribution to zinc alone is limited.

Study Details

PMID:38890302
Participants:380
Impact:changed (significant treatment-specific shifts in alpha/beta diversity and many genera)
Trust score:4/5

liver enzymes (ALT and GGT)

1 evidences

56 overweight/obese NAFLD patients received calorie restriction plus either 30 mg/day zinc or placebo for 12 weeks; zinc raised serum zinc and improved some liver enzymes and waist circumference but did not change steatosis.

Trust comment: Randomized double-blind RCT with clear biochemical endpoints but small sample and short duration limit generalizability.

Study Details

PMID:32020523
Participants:56
Impact:decreased (significant, p<0.05)
Trust score:4/5

liver steatosis / fatty liver index

1 evidences

56 overweight/obese NAFLD patients received calorie restriction plus either 30 mg/day zinc or placebo for 12 weeks; zinc raised serum zinc and improved some liver enzymes and waist circumference but did not change steatosis.

Trust comment: Randomized double-blind RCT with clear biochemical endpoints but small sample and short duration limit generalizability.

Study Details

PMID:32020523
Participants:56
Impact:no significant change between groups
Trust score:4/5

verbal learning (WRAML-2)

1 evidences

Children at risk received combinations of zinc, vitamin A and/or glutamine; girls given the glutamine+zinc+vitamin A combination showed better verbal learning years later.

Trust comment: Randomized, double-blind controlled trial with long-term cognitive follow-up, but subgroup and sex-specific effects with relatively small final group sizes limit certainty.

Study Details

PMID:23644855
Participants:167
Impact:improved in girls receiving glutamine+zinc+vitamin A vs placebo (mean 9.28 vs 7.28; p=0.02)
Trust score:4/5

growth (weight, MUAC, BMI)

1 evidences

1125 adolescent girls received a fortified beverage for up to 12 months; fortification (including zinc) improved hemoglobin, ferritin, retinol, and short-term growth measures.

Trust comment: Large randomized double-blind placebo-controlled trial with objective biochemical and anthropometric outcomes, but multinutrient product means effects cannot be attributed solely to zinc.

Study Details

PMID:17709456
Participants:1125
Impact:greater increases over 6 months (significant, P<0.01)
Trust score:4/5

overall/local/disease-free survival

1 evidences

34 patients with advanced nasopharyngeal carcinoma received 75 mg/day zinc or placebo with chemoradiotherapy; zinc was associated with better 5-year local-free and disease-free survival in this small subgroup analysis.

Trust comment: Double-blind randomized design but very small sample and subgroup analyses reduce reliability of survival benefit attribution to zinc alone.

Study Details

PMID:19402154
Participants:34
Impact:improved 5-year rates in zinc group (statistically significant in reported comparisons)
Trust score:3/5

MMSE score

1 evidences

12-week randomized double-blind trial in overweight/obese women; zinc (30 mg/day) improved some cognitive tests and altered salivary biomarkers but did not change weight versus placebo.

Trust comment: Randomized double-blind RCT with appropriate measures but small sample and differential dropout that limit generalizability.

Study Details

PMID:37892471
Participants:32
Impact:+3.8 points (intragroup improvement, p=0.021)
Trust score:4/5

Stroop test score

1 evidences

12-week randomized double-blind trial in overweight/obese women; zinc (30 mg/day) improved some cognitive tests and altered salivary biomarkers but did not change weight versus placebo.

Trust comment: Randomized double-blind RCT with appropriate measures but small sample and differential dropout that limit generalizability.

Study Details

PMID:37892471
Participants:32
Impact:~−6.2 points vs placebo (better performance; group means 61.97 vs 68.13)
Trust score:4/5

Beck Depression Inventory (BDI) score

1 evidences

12-week randomized double-blind trial in overweight/obese women; zinc (30 mg/day) improved some cognitive tests and altered salivary biomarkers but did not change weight versus placebo.

Trust comment: Randomized double-blind RCT with appropriate measures but small sample and differential dropout that limit generalizability.

Study Details

PMID:37892471
Participants:32
Impact:−28.9 points (intragroup change, p=0.004)
Trust score:4/5

Verbal fluency (TFV)

1 evidences

12-week randomized double-blind trial in overweight/obese women; zinc (30 mg/day) improved some cognitive tests and altered salivary biomarkers but did not change weight versus placebo.

Trust comment: Randomized double-blind RCT with appropriate measures but small sample and differential dropout that limit generalizability.

Study Details

PMID:37892471
Participants:32
Impact:+11.8 points (intragroup change, p=0.036)
Trust score:4/5

Wart clearance (zinc-treated)

1 evidences

Placebo-controlled trial in patients with treatment-resistant viral warts: oral zinc sulphate produced high rates of complete wart clearance in completers.

Trust comment: Randomized placebo-controlled trial showing large effect in completers, but notable dropout and small completer numbers moderate confidence.

Study Details

PMID:11952542
Participants:43
Impact:Complete clearance in 20/23 completers (86.9%) after 2 months
Trust score:4/5

Wart clearance (placebo)

1 evidences

Placebo-controlled trial in patients with treatment-resistant viral warts: oral zinc sulphate produced high rates of complete wart clearance in completers.

Trust comment: Randomized placebo-controlled trial showing large effect in completers, but notable dropout and small completer numbers moderate confidence.

Study Details

PMID:11952542
Participants:43
Impact:0% response in completers during follow-up
Trust score:4/5

Sustained virological response (SVR)

1 evidences

RCT comparing IFN+ribavirin with or without polaprezinc (zinc); zinc addition did not improve sustained virological response but reduced GI side effects.

Trust comment: Well-conducted randomized trial with clear endpoints; negative for efficacy on SVR but reliable on side-effect reduction.

Study Details

PMID:16534882
Participants:102
Impact:No difference (33.3% in both groups)
Trust score:4/5

gastrointestinal side effects

1 evidences

RCT comparing IFN+ribavirin with or without polaprezinc (zinc); zinc addition did not improve sustained virological response but reduced GI side effects.

Trust comment: Well-conducted randomized trial with clear endpoints; negative for efficacy on SVR but reliable on side-effect reduction.

Study Details

PMID:16534882
Participants:102
Impact:Reduced incidence with zinc-containing triple therapy (p=0.019)
Trust score:4/5

Anemia prevalence (MNP)

1 evidences

Cluster RCT sub-study in infants aged 6–12 months: 4 months of daily supplementation (MNP, syrup, or fortified food) increased serum zinc in all groups, with syrup showing the largest increase; MNP reduced anemia prevalence.

Trust comment: Large cluster-randomized trial with biochemical endpoints and high compliance in subgroups, providing strong evidence for zinc status improvement.

Study Details

PMID:35684031
Participants:283
Impact:Anemia prevalence decreased significantly only in MNP group (change −17.4% vs +4.1% in FF, p<0.05)
Trust score:5/5

ferritin

1 evidences

Six-month RCT in Vietnamese infants testing daily or weekly multiple micronutrients (including a small zinc dose) vs placebo; growth and blood micronutrients measured.

Trust comment: Large randomized, double-blind trial with clear biomarker and growth outcomes, but zinc was one component of a multi-micronutrient supplement and dose appears small.

Study Details

PMID:15735111
Participants:306
Impact:+12.1 µg/L in DMM vs -14.7 µg/L in placebo (6 mo)
Trust score:4/5

diarrhea and respiratory illness morbidity

1 evidences

Randomized trial in young children comparing 10 mg/day zinc alone, zinc+multivitamins/minerals, or placebo for ~6 months; morbidity, growth, and plasma micronutrients measured.

Trust comment: Well-conducted randomized controlled trial with adequate sample and objective biomarker and morbidity outcomes; direct zinc supplementation arm provides high internal validity.

Study Details

PMID:14985222
Participants:246
Impact:fewer episodes of diarrhea, dysentery, and respiratory illness with Zn alone vs Zn+VM (and lower cough prevalence vs placebo)
Trust score:5/5

hsCRP

1 evidences

Randomized double-blind placebo-controlled trial giving 45 mg zinc/day for 6 months to healthy elderly adults and measuring plasma zinc and inflammatory/oxidative markers.

Trust comment: Randomized double-blind trial with clear biomarker outcomes though small sample size limits precision and generalizability.

Study Details

PMID:20427734
Participants:40
Impact:decreased with zinc supplementation (vs placebo)
Trust score:4/5

pro-inflammatory markers and oxidative stress

1 evidences

Randomized double-blind placebo-controlled trial giving 45 mg zinc/day for 6 months to healthy elderly adults and measuring plasma zinc and inflammatory/oxidative markers.

Trust comment: Randomized double-blind trial with clear biomarker outcomes though small sample size limits precision and generalizability.

Study Details

PMID:20427734
Participants:40
Impact:decreases in IL-6, MCP-1, VCAM-1, secretory PLA2, and MDA+HAE with zinc supplementation
Trust score:4/5

antioxidant enzyme activity (GPx)

1 evidences

Randomized double-blind trial of daily multivitamin and trace element supplement (including zinc 20 mg) vs placebo in adults measuring serum nutrient levels and antioxidant markers over 6 months.

Trust comment: Large randomized trial showing expected rises in nutrient biomarkers for a multinutrient supplement that included zinc; effects are biomarker-level and part of combined treatment.

Study Details

PMID:9627910
Participants:401
Impact:increase in plasma and red cell GPx activity with supplementation
Trust score:4/5

Haemoglobin (Hb) level

1 evidences

In a cluster randomized trial of young children, iron-containing micronutrient powder (which also contained 5 mg zinc) modestly improved haemoglobin and reduced anaemia and iron deficiency compared to non-iron MNP.

Trust comment: Large double-blind cluster randomized trial with intention-to-treat analysis and appropriate biomarker assessment; high confidence.

Study Details

PMID:33571267
Participants:1806
Impact:+0.35 g/dL (difference-in-difference, iron vs non-iron)
Trust score:5/5

resting metabolic rate (RMR)

1 evidences

Small randomized double-blind trial: co-supplementation with 25 mg zinc + 200 mcg selenium increased resting metabolic rate and serum selenium and improved one functional mobility test versus placebo during an 8-week hypocaloric diet.

Trust comment: Randomized double-blind design but very small sample size limits precision and generalizability.

Study Details

PMID:37513551
Participants:23
Impact:+22.9% (≈ +441 kcal/day in supplementation group vs baseline)
Trust score:3/5

serum selenium

1 evidences

Small randomized double-blind trial: co-supplementation with 25 mg zinc + 200 mcg selenium increased resting metabolic rate and serum selenium and improved one functional mobility test versus placebo during an 8-week hypocaloric diet.

Trust comment: Randomized double-blind design but very small sample size limits precision and generalizability.

Study Details

PMID:37513551
Participants:23
Impact:+36.36 μg/L (from 83.04 to 119.40 μg/L in supplement group)
Trust score:3/5

Timed Up-and-Go (TUG) performance

1 evidences

Small randomized double-blind trial: co-supplementation with 25 mg zinc + 200 mcg selenium increased resting metabolic rate and serum selenium and improved one functional mobility test versus placebo during an 8-week hypocaloric diet.

Trust comment: Randomized double-blind design but very small sample size limits precision and generalizability.

Study Details

PMID:37513551
Participants:23
Impact:-8.8% (improved TUG time in supplement group)
Trust score:3/5

Nosocomial infection/sepsis rate (overall)

1 evidences

Multicenter randomized trial in long-stay pediatric ICU patients found no overall reduction in time-to-nosocomial-infection with enteral zinc/selenium/glutamine plus metoclopramide versus whey protein, though an immunocompromised subgroup showed fewer infections.

Trust comment: Well-conducted multicenter RCT; overall null primary result robust though subgroup finding is from a small subset and should be interpreted cautiously.

Study Details

PMID:22079954
Participants:293
Impact:No significant difference (4.83 vs 4.99 per 100 days; p=0.81)
Trust score:4/5

Time to first nosocomial infection/sepsis

1 evidences

Multicenter randomized trial in long-stay pediatric ICU patients found no overall reduction in time-to-nosocomial-infection with enteral zinc/selenium/glutamine plus metoclopramide versus whey protein, though an immunocompromised subgroup showed fewer infections.

Trust comment: Well-conducted multicenter RCT; overall null primary result robust though subgroup finding is from a small subset and should be interpreted cautiously.

Study Details

PMID:22079954
Participants:293
Impact:No significant difference (median 13.2 d whey vs 12.1 d zinc combo; p=0.29)
Trust score:4/5

Nosocomial infection/sepsis rate (immunocompromised subgroup)

1 evidences

Multicenter randomized trial in long-stay pediatric ICU patients found no overall reduction in time-to-nosocomial-infection with enteral zinc/selenium/glutamine plus metoclopramide versus whey protein, though an immunocompromised subgroup showed fewer infections.

Trust comment: Well-conducted multicenter RCT; overall null primary result robust though subgroup finding is from a small subset and should be interpreted cautiously.

Study Details

PMID:22079954
Participants:293
Impact:Reduced from 6.09 to 1.57 per 100 days (p=0.011) in zinc/Se/glutamine/metoclopramide group
Trust score:4/5

Plasma zinc indicators

1 evidences

Analysis showed that acute phase responses (elevated CRP/AGP) substantially alter biomarkers of micronutrient status, inflating ferritin and distorting vitamin A and zinc indicators, which can misestimate deficiency prevalence.

Trust comment: Moderately large randomized supplementation trial dataset with measured acute phase proteins allowing valid assessment of biomarker confounding.

Study Details

PMID:12368396
Participants:418
Impact:Biomarker values distorted by acute phase response (direction/amount depend on marker; not uniformly quantified here)
Trust score:4/5

Growth and development (6–12 mo)

1 evidences

Randomized double-blind trial in infants found no effect of lowered-phytate cereals on growth, development, or morbidity to 12 months; some subgroup signals linked low serum zinc or low Hb to higher infection risk and later poorer growth.

Trust comment: Double-blind randomized intervention with 300 infants; solid design though some associations are subgroup/observational.

Study Details

PMID:15841764
Participants:300
Impact:No significant differences between diet groups
Trust score:4/5

Diarrhoea risk (IF vs PR group, 12–17 mo)

1 evidences

Randomized double-blind trial in infants found no effect of lowered-phytate cereals on growth, development, or morbidity to 12 months; some subgroup signals linked low serum zinc or low Hb to higher infection risk and later poorer growth.

Trust comment: Double-blind randomized intervention with 300 infants; solid design though some associations are subgroup/observational.

Study Details

PMID:15841764
Participants:300
Impact:+77% risk (IF vs phytate-reduced group; RR ~1.77, 95% CI 1.05–2.97)
Trust score:4/5

Respiratory infection risk with low serum zinc

1 evidences

Randomized double-blind trial in infants found no effect of lowered-phytate cereals on growth, development, or morbidity to 12 months; some subgroup signals linked low serum zinc or low Hb to higher infection risk and later poorer growth.

Trust comment: Double-blind randomized intervention with 300 infants; solid design though some associations are subgroup/observational.

Study Details

PMID:15841764
Participants:300
Impact:RR = 1.74 (higher respiratory infection risk with S‑Zn <10.7 μmol/L)
Trust score:4/5

Linear growth (LAZ decline)

1 evidences

Large community randomized trial comparing zinc formulations/doses found no effect on diarrhea incidence, and a modest improvement in linear growth (smaller decline in LAZ) with the daily high‑zinc/low‑iron MNP formulation.

Trust comment: Large, well-powered randomized community trial with frequent morbidity surveillance and appropriate analyses; high confidence in null diarrhea result and modest growth finding.

Study Details

PMID:35015856
Participants:2886
Impact:Slightly smaller decline in LAZ with daily HiZn LoFe MNP vs placebo (modest improvement; p<0.05)
Trust score:5/5

Overall morbidity

1 evidences

Large community randomized trial comparing zinc formulations/doses found no effect on diarrhea incidence, and a modest improvement in linear growth (smaller decline in LAZ) with the daily high‑zinc/low‑iron MNP formulation.

Trust comment: Large, well-powered randomized community trial with frequent morbidity surveillance and appropriate analyses; high confidence in null diarrhea result and modest growth finding.

Study Details

PMID:35015856
Participants:2886
Impact:No differences in incidence or prevalence of diarrhea across groups
Trust score:5/5

culture conversion

1 evidences

In TB patients, zinc supplementation did not change culture conversion or weight gain; a multi-micronutrient supplement (not zinc) increased weight.

Trust comment: Large randomized double-blind placebo-controlled 2x2 trial (n=499) with clearly reported clinical outcomes.

Study Details

PMID:16135188
Participants:499
Impact:no effect
Trust score:5/5

subclinical infection

1 evidences

Subsample (n=740) from a randomized antenatal trial in rural Nepal: multiple micronutrient supplementation reduced the prevalence of vitamin D deficiency though mean serum 25‑hydroxyvitamin D concentrations were unchanged between first and third trimester.

Trust comment: Randomized controlled trial with biochemical endpoints in a large subsample (n=740); results are specific and well-reported.

Study Details

PMID:16600929
Participants:740
Impact:reduced (folic acid + iron + zinc arm)
Trust score:4/5

depressive symptom severity (HDRS)

1 evidences

Zinc (25 mg/day) added to SSRI treatment reduced depression scores over 12 weeks but did not change measured inflammatory markers or BDNF.

Trust comment: Randomized, double-blind, placebo-controlled RCT with modest sample size and clear HDRS benefit but small overall N; biomarkers showed no change.

Study Details

PMID:23602205
Participants:37
Impact:decrease (significant vs placebo at 12 weeks, P<0.01)
Trust score:4/5

interleukin-6 (IL-6)

1 evidences

Zinc (25 mg/day) added to SSRI treatment reduced depression scores over 12 weeks but did not change measured inflammatory markers or BDNF.

Trust comment: Randomized, double-blind, placebo-controlled RCT with modest sample size and clear HDRS benefit but small overall N; biomarkers showed no change.

Study Details

PMID:23602205
Participants:37
Impact:no significant change vs placebo
Trust score:4/5

tumor necrosis factor-α (TNF-α)

1 evidences

Zinc (25 mg/day) added to SSRI treatment reduced depression scores over 12 weeks but did not change measured inflammatory markers or BDNF.

Trust comment: Randomized, double-blind, placebo-controlled RCT with modest sample size and clear HDRS benefit but small overall N; biomarkers showed no change.

Study Details

PMID:23602205
Participants:37
Impact:no significant change vs placebo
Trust score:4/5

brain-derived neurotrophic factor (BDNF)

1 evidences

Zinc (25 mg/day) added to SSRI treatment reduced depression scores over 12 weeks but did not change measured inflammatory markers or BDNF.

Trust comment: Randomized, double-blind, placebo-controlled RCT with modest sample size and clear HDRS benefit but small overall N; biomarkers showed no change.

Study Details

PMID:23602205
Participants:37
Impact:no significant change vs placebo
Trust score:4/5

CSF zinc level

1 evidences

50 mg ZnSO4 daily for 6 months increased CSF zinc and produced mild clinical and biochemical improvements in SCA2 patients (reduced ataxia subscores, oxidative damage, and saccadic latency).

Trust comment: Randomized double-blind placebo-controlled trial but small sample (n=36); outcomes consistent across biochemical and clinical measures.

Study Details

PMID:21562746
Participants:36
Impact:increase (significant)
Trust score:4/5

ataxia subscores (gait, posture, stance, dysdiadochokinesia)

1 evidences

50 mg ZnSO4 daily for 6 months increased CSF zinc and produced mild clinical and biochemical improvements in SCA2 patients (reduced ataxia subscores, oxidative damage, and saccadic latency).

Trust comment: Randomized double-blind placebo-controlled trial but small sample (n=36); outcomes consistent across biochemical and clinical measures.

Study Details

PMID:21562746
Participants:36
Impact:mild decrease (improvement) vs placebo
Trust score:4/5

lipid oxidative damage

1 evidences

50 mg ZnSO4 daily for 6 months increased CSF zinc and produced mild clinical and biochemical improvements in SCA2 patients (reduced ataxia subscores, oxidative damage, and saccadic latency).

Trust comment: Randomized double-blind placebo-controlled trial but small sample (n=36); outcomes consistent across biochemical and clinical measures.

Study Details

PMID:21562746
Participants:36
Impact:decrease vs placebo
Trust score:4/5

saccadic latency

1 evidences

50 mg ZnSO4 daily for 6 months increased CSF zinc and produced mild clinical and biochemical improvements in SCA2 patients (reduced ataxia subscores, oxidative damage, and saccadic latency).

Trust comment: Randomized double-blind placebo-controlled trial but small sample (n=36); outcomes consistent across biochemical and clinical measures.

Study Details

PMID:21562746
Participants:36
Impact:reduction vs placebo
Trust score:4/5

sperm concentration (subfertile men)

1 evidences

Daily folic acid (5 mg) with zinc sulphate (66 mg) for 26 weeks increased sperm concentration in subfertile men; other semen and endocrine measures were unchanged.

Trust comment: Double-blind placebo-controlled intervention with reasonable sample size, but supplement was combined (folic acid + zinc) so effect cannot be attributed to zinc alone.

Study Details

PMID:16533356
Participants:87
Impact:increase (significant)
Trust score:3/5

FSH, testosterone, inhibin B

1 evidences

Daily folic acid (5 mg) with zinc sulphate (66 mg) for 26 weeks increased sperm concentration in subfertile men; other semen and endocrine measures were unchanged.

Trust comment: Double-blind placebo-controlled intervention with reasonable sample size, but supplement was combined (folic acid + zinc) so effect cannot be attributed to zinc alone.

Study Details

PMID:16533356
Participants:87
Impact:no significant change after intervention
Trust score:3/5

sperm motility and other semen parameters

1 evidences

Daily folic acid (5 mg) with zinc sulphate (66 mg) for 26 weeks increased sperm concentration in subfertile men; other semen and endocrine measures were unchanged.

Trust comment: Double-blind placebo-controlled intervention with reasonable sample size, but supplement was combined (folic acid + zinc) so effect cannot be attributed to zinc alone.

Study Details

PMID:16533356
Participants:87
Impact:no consistent change (aside from concentration increase)
Trust score:3/5

second-trimester plasma homocysteine

1 evidences

Pregnant women with relatively low zinc were randomized to zinc or placebo; study found no predictive value of second-trimester homocysteine for later hypertensive complications and no clear zinc-related benefit reported.

Trust comment: Large randomized trial dataset but reported results do not show a clear effect of zinc on homocysteine or pregnancy complications and reporting focuses on homocysteine associations.

Study Details

PMID:11035317
Participants:437
Impact:no predictive association for subsequent PIH/preeclampsia/IUGR (no clear zinc effect reported)
Trust score:3/5

pregnancy-induced hypertension/preeclampsia/IUGR

1 evidences

Pregnant women with relatively low zinc were randomized to zinc or placebo; study found no predictive value of second-trimester homocysteine for later hypertensive complications and no clear zinc-related benefit reported.

Trust comment: Large randomized trial dataset but reported results do not show a clear effect of zinc on homocysteine or pregnancy complications and reporting focuses on homocysteine associations.

Study Details

PMID:11035317
Participants:437
Impact:no clear reduction attributable to zinc supplementation reported
Trust score:3/5

time to 50% reduction in symptom severity

1 evidences

High‑dose zinc gluconate (50 mg nightly) did not significantly shorten time to 50% symptom reduction or other clinical endpoints in outpatients with COVID-19 compared with usual care.

Trust comment: Randomized pragmatic trial stopped early for futility and open-label design limit certainty despite reasonable sample size at interim (214).

Study Details

PMID:33576820
Participants:214
Impact:no significant difference (zinc mean 5.9 d vs usual care 6.7 d; difference −0.86 d, 95% CI −2.76 to 1.03; not significant)
Trust score:3/5

composite symptom severity at day 5

1 evidences

High‑dose zinc gluconate (50 mg nightly) did not significantly shorten time to 50% symptom reduction or other clinical endpoints in outpatients with COVID-19 compared with usual care.

Trust comment: Randomized pragmatic trial stopped early for futility and open-label design limit certainty despite reasonable sample size at interim (214).

Study Details

PMID:33576820
Participants:214
Impact:no significant difference between groups
Trust score:3/5

hospitalization and death rates

1 evidences

High‑dose zinc gluconate (50 mg nightly) did not significantly shorten time to 50% symptom reduction or other clinical endpoints in outpatients with COVID-19 compared with usual care.

Trust comment: Randomized pragmatic trial stopped early for futility and open-label design limit certainty despite reasonable sample size at interim (214).

Study Details

PMID:33576820
Participants:214
Impact:no significant difference between groups
Trust score:3/5

rotavirus vaccine seroconversion

1 evidences

Daily zinc (5 mg) given with/without probiotic to infants did not significantly improve rotavirus vaccine seroconversion versus placebo.

Trust comment: Large, double-blind randomized placebo-controlled factorial trial in infants with high completion rate and prespecified primary outcome.

Study Details

PMID:28874323
Participants:551
Impact:no significant change with zinc (difference +4.4%, 97.5% CI -4.4% to 13.2%, p=0.272)
Trust score:5/5

fasting insulin and HOMA-IR (severe obesity subgroup)

1 evidences

Three months of combined myo-inositol and zinc (with GOS) did not improve HOMA-IR overall but modestly improved HDL and showed reduced fasting insulin and HOMA-IR in a severe-obesity subgroup.

Trust comment: Randomized double-blind trial but small sample, short duration, and zinc was combined with myo-inositol (attribution to zinc alone unclear).

Study Details

PMID:39781581
Participants:50
Impact:decreased in treated vs placebo (p=0.0137 and p=0.0273)
Trust score:3/5

sickle cell crisis frequency

1 evidences

Zinc sulphate therapy in sickle cell anemia reduced the mean number of crises and infective episodes over 1.5 years versus placebo.

Trust comment: Double-blind randomized controlled trial with good completion; older study but reports large clinically meaningful effects though detailed modern reporting is limited.

Study Details

PMID:8713219
Participants:130
Impact:-53% (mean 2.46 vs 5.29 episodes over 1.5 years in zinc vs placebo, p<0.05)
Trust score:4/5

infective episodes

1 evidences

Zinc sulphate therapy in sickle cell anemia reduced the mean number of crises and infective episodes over 1.5 years versus placebo.

Trust comment: Double-blind randomized controlled trial with good completion; older study but reports large clinically meaningful effects though detailed modern reporting is limited.

Study Details

PMID:8713219
Participants:130
Impact:significant reduction (no numeric value provided)
Trust score:4/5

incidence of pressure ulcers (all stages)

1 evidences

Hip-fracture patients given a multi-nutrient drink (including zinc) did not have fewer pressure ulcers overall but had fewer stage II ulcers and a later onset.

Trust comment: Well-conducted randomized double-blind trial but the supplement contained multiple nutrients (zinc not isolated), so zinc-specific effects cannot be attributed with confidence.

Study Details

PMID:12880608
Participants:103
Impact:55% vs 59% (−4 percentage points; no significant difference)
Trust score:3/5

incidence of stage II pressure ulcers

1 evidences

Hip-fracture patients given a multi-nutrient drink (including zinc) did not have fewer pressure ulcers overall but had fewer stage II ulcers and a later onset.

Trust comment: Well-conducted randomized double-blind trial but the supplement contained multiple nutrients (zinc not isolated), so zinc-specific effects cannot be attributed with confidence.

Study Details

PMID:12880608
Participants:103
Impact:18% vs 28% (−9 percentage points)
Trust score:3/5

time to onset of pressure ulcer

1 evidences

Hip-fracture patients given a multi-nutrient drink (including zinc) did not have fewer pressure ulcers overall but had fewer stage II ulcers and a later onset.

Trust comment: Well-conducted randomized double-blind trial but the supplement contained multiple nutrients (zinc not isolated), so zinc-specific effects cannot be attributed with confidence.

Study Details

PMID:12880608
Participants:103
Impact:3.6 vs 1.6 days (+2.0 days delay)
Trust score:3/5

urinary albumin excretion

1 evidences

In type 2 diabetic patients, combined mineral+vitamin supplementation (including zinc) improved urinary albumin and several metabolic and lipid markers, whereas mineral alone did not show clear benefit.

Trust comment: Randomized, double-blind trial but small group sizes and effects observed in multi-nutrient combinations limit attribution to zinc alone.

Study Details

PMID:16186280
Participants:69
Impact:decreased (significant in vitamin and mineral+vitamin groups)
Trust score:3/5

blood pressure (systolic/diastolic/mean)

1 evidences

In type 2 diabetic patients, combined mineral+vitamin supplementation (including zinc) improved urinary albumin and several metabolic and lipid markers, whereas mineral alone did not show clear benefit.

Trust comment: Randomized, double-blind trial but small group sizes and effects observed in multi-nutrient combinations limit attribution to zinc alone.

Study Details

PMID:16186280
Participants:69
Impact:decreased (significant in mineral+vitamin group)
Trust score:3/5

fasting serum glucose and oxidative marker (MDA)

1 evidences

In type 2 diabetic patients, combined mineral+vitamin supplementation (including zinc) improved urinary albumin and several metabolic and lipid markers, whereas mineral alone did not show clear benefit.

Trust comment: Randomized, double-blind trial but small group sizes and effects observed in multi-nutrient combinations limit attribution to zinc alone.

Study Details

PMID:16186280
Participants:69
Impact:fasting glucose decreased; malondialdehyde decreased (both significant in mineral+vitamin group)
Trust score:3/5

HDL cholesterol and apolipoprotein A1

1 evidences

In type 2 diabetic patients, combined mineral+vitamin supplementation (including zinc) improved urinary albumin and several metabolic and lipid markers, whereas mineral alone did not show clear benefit.

Trust comment: Randomized, double-blind trial but small group sizes and effects observed in multi-nutrient combinations limit attribution to zinc alone.

Study Details

PMID:16186280
Participants:69
Impact:increased (significant in mineral+vitamin group)
Trust score:3/5

morbidity and development

1 evidences

A 6-month lipid-based nutrient supplement (providing zinc among other nutrients) modestly increased length- and weight-for-age in young children, with effects persisting 6 months later.

Trust comment: Large randomized controlled trial with clear growth outcomes, but supplement contained multiple nutrients so zinc-specific effects cannot be isolated.

Study Details

PMID:24225356
Participants:589
Impact:no significant change
Trust score:4/5

nutrient intakes (protein, calcium, iron, magnesium, folate)

1 evidences

Elderly people given a liquid multi-nutrient supplement maintained BMI and had improved intake of several nutrients and some measures of well-being; serum zinc did not change.

Trust comment: Randomized 16-week intervention in older adults with measured biomarkers, but multi-nutrient supplement and lack of zinc-specific effects limit zinc attribution.

Study Details

PMID:10608948
Participants:71
Impact:increased (significant vs baseline in supplemented group)
Trust score:3/5

perceived vitality and general well-being

1 evidences

Elderly people given a liquid multi-nutrient supplement maintained BMI and had improved intake of several nutrients and some measures of well-being; serum zinc did not change.

Trust comment: Randomized 16-week intervention in older adults with measured biomarkers, but multi-nutrient supplement and lack of zinc-specific effects limit zinc attribution.

Study Details

PMID:10608948
Participants:71
Impact:improved (significant vs baseline in supplemented group)
Trust score:3/5

serum homocysteine

1 evidences

A combined nutraceutical (including 12.5 mg zinc) produced a larger reduction in homocysteine than high-dose folic acid alone over two months.

Trust comment: Multicenter randomized trial with clear biochemical outcomes, but intervention combined several active ingredients so zinc's individual contribution is uncertain.

Study Details

PMID:27655522
Participants:104
Impact:21.5 → 10.0 µmol/L (−11.5) in nutraceutical group vs 22.6 → 14.3 µmol/L (−8.3) in control; greater reduction with nutraceutical
Trust score:4/5

percentage achieving homocysteine <10 µmol/L

1 evidences

A combined nutraceutical (including 12.5 mg zinc) produced a larger reduction in homocysteine than high-dose folic acid alone over two months.

Trust comment: Multicenter randomized trial with clear biochemical outcomes, but intervention combined several active ingredients so zinc's individual contribution is uncertain.

Study Details

PMID:27655522
Participants:104
Impact:55.8% in nutraceutical group vs lower in control (significantly higher)
Trust score:4/5

maternal plasma retinol concentration

1 evidences

Pregnant women given zinc (30 mg) during pregnancy had higher maternal plasma retinol postpartum and, when combined with beta-carotene, improved infant retinol and breast-milk retinol.

Trust comment: Randomized, double-blind trial with clear biochemical endpoints and groups allowing assessment of zinc alone and combined with beta-carotene; results credible for vitamin A status effects.

Study Details

PMID:15531679
Participants:170
Impact:higher at 6 months postpartum in women who received zinc (significant)
Trust score:4/5

infant plasma retinol concentration

1 evidences

Pregnant women given zinc (30 mg) during pregnancy had higher maternal plasma retinol postpartum and, when combined with beta-carotene, improved infant retinol and breast-milk retinol.

Trust comment: Randomized, double-blind trial with clear biochemical endpoints and groups allowing assessment of zinc alone and combined with beta-carotene; results credible for vitamin A status effects.

Study Details

PMID:15531679
Participants:170
Impact:higher when mothers received beta-carotene + zinc (frequency of deficiency reduced >30%)
Trust score:4/5

breast-milk retinol concentration

1 evidences

Pregnant women given zinc (30 mg) during pregnancy had higher maternal plasma retinol postpartum and, when combined with beta-carotene, improved infant retinol and breast-milk retinol.

Trust comment: Randomized, double-blind trial with clear biochemical endpoints and groups allowing assessment of zinc alone and combined with beta-carotene; results credible for vitamin A status effects.

Study Details

PMID:15531679
Participants:170
Impact:increased only in beta-carotene + zinc group
Trust score:4/5

proportion with low zinc status

1 evidences

In 150 hemodialysis patients, low/medium-dose zinc+selenium (with vit E) did not lower proportion with low zinc status overall, though medium-dose zinc (50 mg/d) raised serum zinc levels.

Trust comment: Randomized, double-blind trial with appropriate assays and reporting, though modest sample size and conservative doses limit effect detection.

Study Details

PMID:25884981
Participants:150
Impact:No difference between combined intervention and control at 90d (23.9% vs 23.9%) or 180d (28.2% vs 18.6%, P>0.05)
Trust score:4/5

serum zinc concentration (medium dose 50 mg/d)

1 evidences

In 150 hemodialysis patients, low/medium-dose zinc+selenium (with vit E) did not lower proportion with low zinc status overall, though medium-dose zinc (50 mg/d) raised serum zinc levels.

Trust comment: Randomized, double-blind trial with appropriate assays and reporting, though modest sample size and conservative doses limit effect detection.

Study Details

PMID:25884981
Participants:150
Impact:Higher vs control at 90d (1032 vs 932 µg/L, P=0.04) and 180d (1036 vs 972 µg/L, P=0.04)
Trust score:4/5

salt recognition

1 evidences

In 150 hemodialysis patients, low/medium-dose zinc+selenium (with vit E) did not lower proportion with low zinc status overall, though medium-dose zinc (50 mg/d) raised serum zinc levels.

Trust comment: Randomized, double-blind trial with appropriate assays and reporting, though modest sample size and conservative doses limit effect detection.

Study Details

PMID:25884981
Participants:150
Impact:Improved at 90d in medium dose vs control (55.3% vs 32.6%, P=0.03) but not at 180d
Trust score:4/5

fetal loss

1 evidences

Maternal multiple micronutrient supplements (which included 10 µg vitamin D) did not reduce overall fetal loss or early infant mortality; effects of vitamin D alone were not separable.

Trust comment: Large, cluster-randomized, double-blind trial with robust sample size; subgroup effects require cautious interpretation.

Study Details

PMID:14668283
Participants:4926
Impact:No reduction
Trust score:5/5

3-month infant mortality (preterm infants)

1 evidences

Maternal multiple micronutrient supplements (which included 10 µg vitamin D) did not reduce overall fetal loss or early infant mortality; effects of vitamin D alone were not separable.

Trust comment: Large, cluster-randomized, double-blind trial with robust sample size; subgroup effects require cautious interpretation.

Study Details

PMID:14668283
Participants:4926
Impact:FA+iron+zinc RR 0.77 (95% CI 0.45–1.32) (not statistically significant)
Trust score:5/5

weight gain (WAZ)

1 evidences

In 403 children with TB, zinc supplementation did not change weight gain or chest X‑ray lesion clearance over 6 months; micronutrient supplementation was associated with slightly faster height gain.

Trust comment: Well-conducted randomized, double-blind trial with adequate sample size and registered design; effects specific to zinc were largely null.

Study Details

PMID:25332327
Participants:403
Impact:No significant difference with zinc (6‑mo WAZ Δ ≈0.75 with or without zinc)
Trust score:4/5

CXR lesion improvement

1 evidences

In 403 children with TB, zinc supplementation did not change weight gain or chest X‑ray lesion clearance over 6 months; micronutrient supplementation was associated with slightly faster height gain.

Trust comment: Well-conducted randomized, double-blind trial with adequate sample size and registered design; effects specific to zinc were largely null.

Study Details

PMID:25332327
Participants:403
Impact:No difference with zinc
Trust score:4/5

height gain (HAZ)

1 evidences

In 403 children with TB, zinc supplementation did not change weight gain or chest X‑ray lesion clearance over 6 months; micronutrient supplementation was associated with slightly faster height gain.

Trust comment: Well-conducted randomized, double-blind trial with adequate sample size and registered design; effects specific to zinc were largely null.

Study Details

PMID:25332327
Participants:403
Impact:Micronutrients improved height gain Δ=+0.08 (P=0.014)
Trust score:4/5

intellectual functioning (UNIT T score)

1 evidences

Pregnant women received iron/folic acid, iron/folic acid/zinc, or multiple micronutrients; the iron/folic acid/zinc arm showed no significant benefits on children's cognitive or motor outcomes versus control.

Trust comment: Large randomized prenatal trial with 7–9 y follow-up; zinc was included as part of a supplementation arm but showed no significant effects versus control.

Study Details

PMID:21177506
Participants:676
Impact:no significant change vs control (iron/folic acid/zinc adjusted mean difference 0.73; 95% CI -0.95 to 2.42)
Trust score:4/5

executive function (tests)

1 evidences

Pregnant women received iron/folic acid, iron/folic acid/zinc, or multiple micronutrients; the iron/folic acid/zinc arm showed no significant benefits on children's cognitive or motor outcomes versus control.

Trust comment: Large randomized prenatal trial with 7–9 y follow-up; zinc was included as part of a supplementation arm but showed no significant effects versus control.

Study Details

PMID:21177506
Participants:676
Impact:no significant change vs control in iron/folic acid/zinc arm
Trust score:4/5

motor function (MABC/finger-tapping)

1 evidences

Pregnant women received iron/folic acid, iron/folic acid/zinc, or multiple micronutrients; the iron/folic acid/zinc arm showed no significant benefits on children's cognitive or motor outcomes versus control.

Trust comment: Large randomized prenatal trial with 7–9 y follow-up; zinc was included as part of a supplementation arm but showed no significant effects versus control.

Study Details

PMID:21177506
Participants:676
Impact:no significant difference vs control for iron/folic acid/zinc arm
Trust score:4/5

weight loss / BMI loss

1 evidences

Oral cancer patients randomized to professional nutritional support (including individualized micronutrient supplements such as calcium tablets when indicated) lost less weight and had more stable lab values including calcium compared with standard care.

Trust comment: Randomized clinical trial but small (n=46), supplementation was individualized and not zinc-only so zinc-specific effect cannot be isolated.

Study Details

PMID:35987809
Participants:46
Impact:significantly less weight and BMI loss in intervention vs control at T2 and T4; malnourished patients 27.27% (intervention) vs 45.83% (control)
Trust score:3/5

zinc laboratory level

1 evidences

Oral cancer patients randomized to professional nutritional support (including individualized micronutrient supplements such as calcium tablets when indicated) lost less weight and had more stable lab values including calcium compared with standard care.

Trust comment: Randomized clinical trial but small (n=46), supplementation was individualized and not zinc-only so zinc-specific effect cannot be isolated.

Study Details

PMID:35987809
Participants:46
Impact:zinc remained below reference in control at 3 months but was no longer below reference in the intervention group by T3 (control stagnated below reference)
Trust score:3/5

gastrointestinal complaints

1 evidences

Oral cancer patients randomized to professional nutritional support (including individualized micronutrient supplements such as calcium tablets when indicated) lost less weight and had more stable lab values including calcium compared with standard care.

Trust comment: Randomized clinical trial but small (n=46), supplementation was individualized and not zinc-only so zinc-specific effect cannot be isolated.

Study Details

PMID:35987809
Participants:46
Impact:fewer GI complaints in intervention vs control at 3 months (P = 0.0062)
Trust score:3/5

wound surface area

1 evidences

A specialized oral nutritional supplement containing zinc plus other nutrients significantly improved healing of hard-to-heal wounds versus control.

Trust comment: Small randomized trial of a combined-nutrient supplement including zinc; positive wound-healing signals but zinc-specific contribution unclear.

Study Details

PMID:33439085
Participants:30
Impact:significant reduction with specialized ONS vs control (P = 0.004)
Trust score:3/5

wound-edge growth rate

1 evidences

A specialized oral nutritional supplement containing zinc plus other nutrients significantly improved healing of hard-to-heal wounds versus control.

Trust comment: Small randomized trial of a combined-nutrient supplement including zinc; positive wound-healing signals but zinc-specific contribution unclear.

Study Details

PMID:33439085
Participants:30
Impact:mean weekly edge growth 1.85 mm (diabetics) and 3.0 mm (non-diabetics), ~2.9× and 4.6× expected rates
Trust score:3/5

opportunistic infections

1 evidences

In HIV+ patients on ART, zinc supplementation reduced the risk of opportunistic infections but did not significantly change CD4 counts.

Trust comment: Randomized double-blind clinical trial in 146 patients with clear clinical endpoints; effect sizes partly not reported numerically but statistical significance given.

Study Details

PMID:30888253
Participants:146
Impact:decreased (statistically significant)
Trust score:4/5

serum zinc deficiency prevalence

1 evidences

In HIV+ patients on ART, zinc supplementation reduced the risk of opportunistic infections but did not significantly change CD4 counts.

Trust comment: Randomized double-blind clinical trial in 146 patients with clear clinical endpoints; effect sizes partly not reported numerically but statistical significance given.

Study Details

PMID:30888253
Participants:146
Impact:44.7% final incidence in zinc group
Trust score:4/5

gingival bleeding (bleeding sites)

1 evidences

A zinc/arginine dentifrice did not significantly reduce gingival bleeding sites or plaque versus the negative control over 3 months.

Trust comment: Well-designed randomized, double-blind, parallel-group trial with 154 completers directly testing a zinc-containing dentifrice.

Study Details

PMID:33940670
Participants:154
Impact:no significant difference vs negative control
Trust score:4/5

plaque level

1 evidences

A zinc/arginine dentifrice did not significantly reduce gingival bleeding sites or plaque versus the negative control over 3 months.

Trust comment: Well-designed randomized, double-blind, parallel-group trial with 154 completers directly testing a zinc-containing dentifrice.

Study Details

PMID:33940670
Participants:154
Impact:no significant difference vs negative control
Trust score:4/5

oral microbial counts

1 evidences

A dentifrice containing stannous fluoride/sodium hexametaphosphate/zinc lactate reduced oral microbial counts modestly (14–43% for many outcomes) versus NaF; zinc was part of a combined formulation so its isolated effect is unclear.

Trust comment: Small, triple-crossover study with direct microbiological measures, but zinc was part of a multi-ingredient formulation so zinc-specific effects are not isolated.

Study Details

PMID:22924756
Participants:35
Impact:decreased 14–43% for 14 of 24 outcomes (SnF2/SHMP/zinc lactate vs NaF)
Trust score:3/5

Cmax (serum zinc)

1 evidences

Polaprezinc (zinc–L-carnosine) test and reference granules were bioequivalent; a high-fat meal reduced zinc absorption/exposure; formulations were generally well tolerated.

Trust comment: Randomized, two-period crossover bioequivalence study in healthy volunteers with detailed PK measures and adequate reporting.

Study Details

PMID:40663018
Participants:45
Impact:fasting Cmax ~1.30 μg/mL (75 mg); fed Cmax ~0.91 μg/mL (300 mg)
Trust score:4/5

AUC (zinc exposure)

1 evidences

Polaprezinc (zinc–L-carnosine) test and reference granules were bioequivalent; a high-fat meal reduced zinc absorption/exposure; formulations were generally well tolerated.

Trust comment: Randomized, two-period crossover bioequivalence study in healthy volunteers with detailed PK measures and adequate reporting.

Study Details

PMID:40663018
Participants:45
Impact:AUC0–t fasting ~4.06 h·μg/mL; fed ~3.26 h·μg/mL (reduced with high-fat meal)
Trust score:4/5

bioequivalence

1 evidences

Polaprezinc (zinc–L-carnosine) test and reference granules were bioequivalent; a high-fat meal reduced zinc absorption/exposure; formulations were generally well tolerated.

Trust comment: Randomized, two-period crossover bioequivalence study in healthy volunteers with detailed PK measures and adequate reporting.

Study Details

PMID:40663018
Participants:45
Impact:test vs reference bioequivalent (90% CI within 80–125% for Cmax and AUC)
Trust score:4/5

plasma zinc concentration (prevalence low status)

1 evidences

In 208 Ghanaian infants, low plasma zinc prevalence was low (4% at 6 mo, 6% at 12 mo); higher birth weight and socioeconomic status were associated with better zinc status, while elevated CRP (infection) was associated with lower zinc.

Trust comment: Moderate-quality observational cohort with 208 infants and measured zinc outcomes; associations (not causal) reported.

Study Details

PMID:10720170
Participants:208
Impact:4% low at 6 mo; 6% low at 12 mo
Trust score:3/5

inflammation (CRP) effect on zinc

1 evidences

In 208 Ghanaian infants, low plasma zinc prevalence was low (4% at 6 mo, 6% at 12 mo); higher birth weight and socioeconomic status were associated with better zinc status, while elevated CRP (infection) was associated with lower zinc.

Trust comment: Moderate-quality observational cohort with 208 infants and measured zinc outcomes; associations (not causal) reported.

Study Details

PMID:10720170
Participants:208
Impact:elevated CRP associated with lower plasma zinc concentrations
Trust score:3/5

Reduced glutathione (GSH)

1 evidences

In SICU patients requiring PN, parenteral nutrition significantly increased plasma zinc levels over 7 days; glutamine-supplemented PN improved glutathione but zinc rose with PN regardless of glutamine.

Trust comment: Randomized, double-blind trial in 59 critically ill patients with clear biomarker outcomes; applicable to hospitalized PN patients though not general population.

Study Details

PMID:18065204
Participants:59
Impact:improved with glutamine-supplemented PN in non-pancreatic surgery subgroup (PN -0.27 μM vs Gln-PN +0.26 μM, P<0.03)
Trust score:4/5

serum zinc normalization

1 evidences

Giving daily zinc (10 mg) to newborns increased blood zinc normalization but did not improve antibody responses to oral polio vaccine.

Trust comment: Large double-blind randomized controlled trial in infants with objective biomarker and immunogenicity endpoints; well-conducted and results clear.

Study Details

PMID:25500307
Participants:404
Impact:+44.5 percentage points (71.9% vs 27.4% at week 18)
Trust score:4/5

OPV immunogenicity (seroconversion PV1/PV2/PV3)

1 evidences

Giving daily zinc (10 mg) to newborns increased blood zinc normalization but did not improve antibody responses to oral polio vaccine.

Trust comment: Large double-blind randomized controlled trial in infants with objective biomarker and immunogenicity endpoints; well-conducted and results clear.

Study Details

PMID:25500307
Participants:404
Impact:no significant change between groups
Trust score:4/5

intestinal barrier function (lactulose:mannitol ratio / % lactulose, mannitol)

1 evidences

In undernourished children, glutamine improved weight-for-height (WHZ) and intestinal barrier; adding zinc and vitamin A produced small, non-significant additional growth benefit and did not change leptin/IGF-1/adiponectin/cortisol levels.

Trust comment: Randomized, double-blind, community trial with pre-specified biochemical and anthropometric endpoints; zinc was given only as part of combination so zinc-alone effects are unclear.

Study Details

PMID:24714829
Participants:314
Impact:improved (decreased lactulose % and mannitol excretion) with glutamine; nutrients combined decreased lactulose:mannitol ratio vs glutamine (p=0.041)
Trust score:4/5

plasma hormones (leptin, IGF-1, adiponectin, cortisol)

1 evidences

In undernourished children, glutamine improved weight-for-height (WHZ) and intestinal barrier; adding zinc and vitamin A produced small, non-significant additional growth benefit and did not change leptin/IGF-1/adiponectin/cortisol levels.

Trust comment: Randomized, double-blind, community trial with pre-specified biochemical and anthropometric endpoints; zinc was given only as part of combination so zinc-alone effects are unclear.

Study Details

PMID:24714829
Participants:314
Impact:no significant changes after glutamine or glutamine+zinc+vitA (p>0.05)
Trust score:4/5

childhood mortality (birth to 7 years) — maternal folic acid–iron–zinc

1 evidences

Maternal antenatal iron–folic acid reduced child mortality to age 7; the folic acid–iron–zinc group showed a non-significant reduction in childhood mortality (HR=0.80, 95% CI 0.58–1.11).

Trust comment: Large cluster-randomized trial with long follow-up; zinc was delivered as part of combination supplements and the folic acid–iron–zinc arm did not show a significant effect on mortality.

Study Details

PMID:19778983
Participants:3761
Impact:HR = 0.80 (95% CI: 0.58–1.11), not statistically significant
Trust score:4/5

15-F2t-isoprostane (oxidative stress biomarker)

1 evidences

In patients with prior nonmelanoma skin cancer, 60 days of antioxidant supplementation including zinc produced modest reductions in oxidative stress biomarkers (notably 15-F2t-isoprostane) but differences versus placebo were not statistically significant.

Trust comment: Randomized phase II trial but small sample and short duration; biomarker changes were not significant, limiting confidence in efficacy.

Study Details

PMID:26509174
Participants:60
Impact:mean decrease after supplementation (87.3 pg/mL vs 76.8 pg/mL) but difference vs placebo not statistically significant
Trust score:3/5

total antioxidant capacity / TBARS

1 evidences

In patients with prior nonmelanoma skin cancer, 60 days of antioxidant supplementation including zinc produced modest reductions in oxidative stress biomarkers (notably 15-F2t-isoprostane) but differences versus placebo were not statistically significant.

Trust comment: Randomized phase II trial but small sample and short duration; biomarker changes were not significant, limiting confidence in efficacy.

Study Details

PMID:26509174
Participants:60
Impact:small, non-significant changes after supplementation
Trust score:3/5

adenoma recurrence (large bowel)

1 evidences

In post-polypectomy patients, long-term daily antioxidant supplementation that included zinc (30 mg) reduced adenoma recurrence over follow-up (~39% reduced risk; adjusted HR=0.61, 95% CI 0.41–0.92).

Trust comment: Double-blind randomized trial with long follow-up and statistically significant reduction in recurrence, but intervention was a multi-nutrient mix so effects cannot be attributed to zinc alone.

Study Details

PMID:23065023
Participants:330
Impact:~39% risk reduction (adjusted HR = 0.61; 95% CI 0.41–0.92); 15-year cumulative incidence 48.3% vs 64.5% (HR = 0.59)
Trust score:4/5

puerperal sepsis

1 evidences

Cluster-randomized trial in rural Nepal found some differences in labor and postpartum outcomes across supplement groups; folic acid–iron–zinc was associated with lower puerperal sepsis versus control.

Trust comment: Large cluster-randomized multicenter trial with high completion rates; effects are reported for combined micronutrient groups rather than zinc alone.

Study Details

PMID:19368922
Participants:3564
Impact:reduced (P<0.05) with folic acid-iron-zinc and some other supplement groups vs control
Trust score:4/5

dysfunctional labor

1 evidences

Cluster-randomized trial in rural Nepal found some differences in labor and postpartum outcomes across supplement groups; folic acid–iron–zinc was associated with lower puerperal sepsis versus control.

Trust comment: Large cluster-randomized multicenter trial with high completion rates; effects are reported for combined micronutrient groups rather than zinc alone.

Study Details

PMID:19368922
Participants:3564
Impact:increased (RR 1.28) with multiple micronutrient supplementation
Trust score:4/5

postpartum hemorrhage

1 evidences

Cluster-randomized trial in rural Nepal found some differences in labor and postpartum outcomes across supplement groups; folic acid–iron–zinc was associated with lower puerperal sepsis versus control.

Trust comment: Large cluster-randomized multicenter trial with high completion rates; effects are reported for combined micronutrient groups rather than zinc alone.

Study Details

PMID:19368922
Participants:3564
Impact:reduced (RR 0.59) with folic acid-iron (reported)
Trust score:4/5

total antioxidant status

1 evidences

Graves' disease patients treated with methimazole were given antioxidant supplements (no zinc in the supplement) and erythrocyte SOD, Cu, Zn and total antioxidant status were followed for 60 days.

Trust comment: Controlled study on humans with moderate sample size; zinc was measured but not supplemented, and exact numeric changes for zinc are not provided in the text.

Study Details

PMID:15899653
Participants:55
Impact:significant between-group difference (supplement vs control) — exact magnitude not reported
Trust score:3/5

weight gain (7 months)

1 evidences

Randomized trial of zinc (45 mg) and multivitamin/mineral (MVM) supplementation during 8 months of TB treatment in 499 patients, assessing weight gain and survival.

Trust comment: Large randomized factorial trial with clear endpoints and reported effect sizes; subgroup finding for HIV co-infected is notable but may need replication.

Study Details

PMID:16571156
Participants:499
Impact:+2.37 kg (Zn+MVM combined vs others; 95% CI 0.91 to 3.83)
Trust score:4/5

mortality in HIV co-infected patients

1 evidences

Randomized trial of zinc (45 mg) and multivitamin/mineral (MVM) supplementation during 8 months of TB treatment in 499 patients, assessing weight gain and survival.

Trust comment: Large randomized factorial trial with clear endpoints and reported effect sizes; subgroup finding for HIV co-infected is notable but may need replication.

Study Details

PMID:16571156
Participants:499
Impact:RR 0.29 (Zn+MVM combined vs placebo; 95% CI 0.10 to 0.80) — reduced mortality
Trust score:4/5

other serum antioxidants/trace elements (vitamin C, alpha-tocopherol, beta-carotene, selenium)

1 evidences

Double-blind randomized trial in 106 alcohol-dependent inpatients comparing 21 days of micronutrient supplementation (including zinc 20 mg) versus placebo and measuring serum vitamin and trace element levels.

Trust comment: Randomized double-blind trial with adequate sample size and clear biomarker outcomes; changes are biochemical, short-term.

Study Details

PMID:12897045
Participants:106
Impact:improved in supplement group vs placebo (significant)
Trust score:4/5

total motile spermatozoa (A+B+C)

1 evidences

Adding zinc-arginyl-glycinate to Prostatilen increased sperm motility and improved sperm morphology after 10 days of treatment in men with chronic prostatitis and impaired spermatogenesis.

Trust comment: Randomized multicenter trial with objective semen measures but short treatment (10 days) and open-label design limit confidence.

Study Details

PMID:36318852
Participants:98
Impact:+14.3% (Prostatilen AC) vs +4.1% (control)
Trust score:3/5

fast progressive sperm motility

1 evidences

Adding zinc-arginyl-glycinate to Prostatilen increased sperm motility and improved sperm morphology after 10 days of treatment in men with chronic prostatitis and impaired spermatogenesis.

Trust comment: Randomized multicenter trial with objective semen measures but short treatment (10 days) and open-label design limit confidence.

Study Details

PMID:36318852
Participants:98
Impact:significant increase (Prostatilen AC vs control; p=0.0004)
Trust score:3/5

normal sperm morphology

1 evidences

Adding zinc-arginyl-glycinate to Prostatilen increased sperm motility and improved sperm morphology after 10 days of treatment in men with chronic prostatitis and impaired spermatogenesis.

Trust comment: Randomized multicenter trial with objective semen measures but short treatment (10 days) and open-label design limit confidence.

Study Details

PMID:36318852
Participants:98
Impact:significant increase (Prostatilen AC vs control; p=0.0118)
Trust score:3/5

diarrheal disease

1 evidences

Daily zinc supplementation in infants (6–15 months) did not change overall rates of diarrhea or respiratory infections over 12 months, though some subgroup benefits were observed.

Trust comment: Large double-blind randomized placebo-controlled trial with clear endpoints; subgroup heterogeneity complicates interpretation.

Study Details

PMID:16522919
Participants:736
Impact:no overall effect; subgroup decrease in children from households with dirt floors and whose mothers were more educated
Trust score:4/5

respiratory tract infections (cough with fever)

1 evidences

Daily zinc supplementation in infants (6–15 months) did not change overall rates of diarrhea or respiratory infections over 12 months, though some subgroup benefits were observed.

Trust comment: Large double-blind randomized placebo-controlled trial with clear endpoints; subgroup heterogeneity complicates interpretation.

Study Details

PMID:16522919
Participants:736
Impact:no overall effect
Trust score:4/5

breast milk zinc concentration

1 evidences

In HIV-infected lactating women, maternal lipid-based nutrient supplement did not change milk zinc, but maternal antiretroviral therapy reduced milk zinc and copper concentrations in early lactation.

Trust comment: Large randomized factorial trial with repeated measures and appropriate lab analyses; robust design and sample size for milk mineral outcomes.

Study Details

PMID:28851037
Participants:535
Impact:no effect of LNS; ARV associated with ~5–8% reduction in median milk zinc at 2 weeks (significant)
Trust score:5/5

breast milk copper concentration

1 evidences

In HIV-infected lactating women, maternal lipid-based nutrient supplement did not change milk zinc, but maternal antiretroviral therapy reduced milk zinc and copper concentrations in early lactation.

Trust comment: Large randomized factorial trial with repeated measures and appropriate lab analyses; robust design and sample size for milk mineral outcomes.

Study Details

PMID:28851037
Participants:535
Impact:ARV associated with a small but significant decrease at 2 weeks (5–8% range reported)
Trust score:5/5