RESUMO
Iron and zinc are trace minerals that are of critical importance to the young infant for normal growth and development.To investigate the effect of zinc and iron supplementation on growth and mental performance in infants. This study is a r and omized controlled trial conducted in an old crowded district in Cairo, Egypt. At baseline 119 infants aged 4 months [ +/- 15 days] randomly assigned to receive 5ml per day of either supplement A [multivitamins with zinc and iron added] or supplement B [multivitamins without zinc and iron]. Infants were examined clinically and anthropometric measures [weight, length and knee-heel] were taken. They were followed up for history taking [diet and morbidity], clinical examination and anthropometric measurements every 15 days till the age of 10 months +/- 2 weeks. Mental and Motor development were assessed at baseline [4 months] and at the end of the study [10 month +/- 2 weeks] using the Bayley Scale of Infant Development [BSID II]. The study was single blinded for clinical and growth assessment, while it was double blinded for developmental evaluation.Infants included in the study were those who had at least 3 recordings of anthropometric measurements [n=69 infants]. Repeated measures ANOVA test was used to compare differences between the groups, change with time, and group and time interaction. At the end of the study the zinc and iron supplemented group showed a slight but insignificant rise in anthropometric measurements. Developmental performance [MDI and PDI] also showed an insignificant rise at the end of the study in the supplemented group. Change with time is the same in both groups, differences between groups is the same at each time period. Comparison of growth rate between the two groups showed a trend towards increased velocity of all growth parameters in the zinc and iron supplemented group, however the difference between the two groups is not significant. Comparison of number of episodes of fever, upper respiratory tract infection [URTI] lower respiratory tract infection [LRTI] and diarrhea between the two groups showed no statistical differences, though we could see an increase in the percent number of infants with morbidity [except for URTI] in the group not supplemented with iron and zinc.Infants in both groups gained weight and length similar to reference data. In spite of this, we see a trend towards increased velocity of weight in the zinc and iron supplemented group as compared to the non-supplemented group. This is also associated with an apparent decrease in morbidity in the supplemented group