Long-term effects of iron and zinc supplementation during infancy on cognitive function at 9 y of age in northeast Thai children: a follow-up study

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#child #child-development #cognition-disorders #cross-sectional-studies #dietary-supplements

Long-term effects of iron and zinc supplementation during infancy on cognitive function at 9 y of age in northeast Thai children: a follow-up study

Pongcharoen et al., 2011 | Am J Clin Nutr | Rct

Citation

Pongcharoen Tippawan, DiGirolamo Ann M, ... Martorell Reynaldo. Long-term effects of iron and zinc supplementation during infancy on cognitive function at 9 y of age in northeast Thai children: a follow-up study. Am J Clin Nutr. 2011-Mar;93(3):636-43. doi:10.3945/ajcn.110.002220

Abstract

BACKGROUND: Iron and zinc are important micronutrients for child growth and development. One would expect that iron and zinc supplementation in infancy would affect long-term cognitive development and school achievement, but this has not been evaluated. OBJECTIVE: We investigated the effect of iron or zinc supplementation or both during infancy on cognitive performance 8 y later. DESIGN: A follow-up study was performed in 560 children aged 9 y or 92% of those who had participated in a randomized controlled trial involving 4 groups who received daily iron, zinc, iron plus zinc, or a placebo at 4-6 mo of age for 6 mo. Cognitive performance was assessed by using the Wechsler Intelligence Scale for Children-Third Edition (Thai version), the Raven's Colored Progressive Matrices (CPM), and school performance tests. General linear mixed models were used to assess long-term effects. RESULTS: No significant differences in any of the outcomes at 9 y of age were observed at follow-up between the 4 groups. Mean intelligence quotients ranged across groups from 92.9 to 93.7 for full scale, 93.9-95.4 for verbal, and 93.1-94.0 for performance. The Raven's CPM score ranged from 21.4 to 22.4. CONCLUSION: Supplementation with iron or zinc or both during infancy does not lead to long-term cognitive improvement in 9-y-old children. This trial was registered at clinicaltrials.gov as NCT00824304.

Key Findings

No significant differences in any of the outcomes at 9 y of age were observed at follow-up between the 4 groups. Mean intelligence quotients ranged across groups from 92.9 to 93.7 for full scale, 93.9-95.4 for verbal, and 93.1-94.0 for performance. The Raven's CPM score ranged from 21.4 to 22.4.

Outcomes Measured

  • Requires manual extraction

Population

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

MeSH Terms

  • Child
  • Child Development
  • Cognition Disorders
  • Cross-Sectional Studies
  • Dietary Supplements
  • Female
  • Follow-Up Studies
  • Humans
  • Infant
  • Intelligence
  • Intelligence Tests
  • Iron, Dietary
  • Male
  • Task Performance and Analysis
  • Thailand
  • Zinc

Evidence Classification

  • Level: Rct
  • Publication Types: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't
  • Vertical: zinc-mood

Provenance

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