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

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

Iron and zinc supplementation for six months during infancy does not lead to cognitive improvement in nine year old children.

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 so far been evaluated.

This follow-on study sought to investigate the effect of iron or zinc supplementation or both on cognitive performance of 560 nine year old children eight years after they had received daily iron, zinc, iron plus zinc, or a placebo at four to six months of age for a period six months.

Cognitive performance was assessed by using the Wechsler Intelligence Scale for Children, the Raven's Colored Progressive Matrices (CPM), and school performance tests. General linear mixed models were used to assess long-term effects.

No significant differences in any of the outcomes at nine years of age were observed at follow-up between the four supplementation groups. These findings suggest that supplementation with iron or zinc or both during infancy does not lead to long-term cognitive improvement in nine year old children.

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