Effect of zinc supplementation on mortality in under 5-year children: a systematic review and meta-analysis of randomized clinical trials

Rouhani et al., 2022 | Eur J Nutr | Meta Analysis

Citation

Rouhani Parisa, Rezaei Kelishadi Mahnaz, Saneei Parvane. Effect of zinc supplementation on mortality in under 5-year children: a systematic review and meta-analysis of randomized clinical trials. Eur J Nutr. 2022-Feb;61(1):37-54. doi:10.1007/s00394-021-02604-1

Abstract

BACKGROUND: Several clinical trials evaluated the effect of zinc supplementation on mortality in children, but the results were inconsistent. We aimed to conduct a systematic review and meta-analysis on the impact of zinc supplementation on mortality in under 5-year children. METHODS: A comprehensive search was conducted using the electronic (PubMed, Scopus, Web of Science) databases, and Google Scholar, up to June 2020. Randomized clinical trials (RCTs) that reported the effect of zinc supplementation on death incidence in under 5-year children were included in the analysis. Screening was performed based on title/abstract and full-text. A random effects model was applied to calculate the summary relative risk (SRR). Risk of Bias 2.0 tool was used to rate the quality of trials. The body of evidence was assessed by the GRADE approach. RESULTS: Combining 30 RRs from 28 RCTs including 237,068 participants revealed that zinc supplementation has significantly reduced the risk of all-causes mortality by 16% in children (SRR: 0.84, 95% CI: 0.74, 0.96). A follow-up duration of less than 1 year after supplementation resulted in 54% reduced risk of mortality (0.46; 0.33, 0.63) with no heterogeneity between investigations. Subgroup analysis by zinc dosage showed that assigning ≥ 10 mg/d zinc to under five children and duration of less than 11 months of intervention decreased the risk of all-cause mortality by 44% (0.56; 0.42, 0.75) and 48% (0.52; 0.38, 0.72), respectively. In low birth weight (LBW) infants, zinc supplementation was reduced all-cause mortality by 52% (0.48; 0.23, 1.00). Zinc supplementation significantly reduced the risk of death from pneumonia (0.70: 0.64, 0.98) and infection (0.54; 0.39, 0.76), also changed the risk of mortality from diarrhea by 15% (0.85; 0.70, 1.03) and sepsis by 57% (0.43; 0.18, 1.02). CONCLUSION: This meta-analysis on RCTs revealed that zinc supplementation in under 5-year children has significantly reduced the risk of all-cause mortality. Notable decreases were found in trials with a dose of 10 mg/d or more zinc supplementation, a maximum of 11 months of supplementation, a follow-up less than one year and especially in LBW infants.

Key Findings

Combining 30 RRs from 28 RCTs including 237,068 participants revealed that zinc supplementation has significantly reduced the risk of all-causes mortality by 16% in children (SRR: 0.84, 95% CI: 0.74, 0.96). A follow-up duration of less than 1 year after supplementation resulted in 54% reduced risk of mortality (0.46; 0.33, 0.63) with no heterogeneity between investigations. Subgroup analysis by zinc dosage showed that assigning ≥ 10 mg/d zinc to under five children and duration of less than 11 m

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 237068
Age Range See abstract
Condition See abstract

MeSH Terms

  • Child
  • Diarrhea
  • Dietary Supplements
  • Humans
  • Infant
  • Infant, Low Birth Weight
  • Infant, Newborn
  • Randomized Controlled Trials as Topic
  • Zinc

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Systematic Review
  • Vertical: zinc

Provenance


Source extracted via PubMed E-utilities API on 2026-04-09