Zinc supplementation during pregnancy and effects on mental development and behaviour of infants: a follow-up study

Background Zinc deficiency is widely prevalent in developing countries. Zinc supplements given to Bangladeshi pregnant women have been shown to reduce infants' infectious disease morbidity. We assessed these infants at age 13 months to establish the effect of antenatal zinc supplementation on infant development and behaviour. Methods The study originally consisted of 559 pregnant women who were randomly allocated to zinc (30 mg daily) or placebo (cellulose) from 4 months' gestation to delivery. The effect of zinc supplementation on pregnancy outcome and on infant growth and morbidity in the first 6 months was assessed. We then randomly selected a subsample of 168 infants from 383 who completed the study at 6 months. When babies in this subsample reached age 13…