Effect of micronutrient supplementation on linear growth of children

This review summarizes the results of published, randomized clinical trials that have examined the impact of administration of micronutrients, singly or in combination to infants, preschool and school children on linear growt h. Supplementation of single micronutrients resulted in small or no benefit s on linear growth. A meta-analysis of zinc supplementation trials confirme d that zinc has a significant but small impact (0.22 sd units) on length ga in in children 0-13 years of age. However, a recent study reported a substa ntially greater benefit (>1 sd) in stunted and non-stunted breast-fed infan ts 6-12 months of age. With iron supplementation, a beneficial effect was f ound only in anemic children. Vitamin A supplementation trials have reporte d little or no benefit on linear growth. Data currently available suggest s ome impact in children with clinical or biochemical vitamin A deficiency, b ut this issue needs confirmation. Few studies could be identified where a c ombination of micronutrients was given as a supplement or as fortified food ; in the latter set of studies energy availability was assured. The impact on length without multiple micronutrient supplementation was no greater tha n that observed with single micronutrients. In conclusion, zinc and iron se em to have a modest effect on linear growth in deficient populations. Vitam in A is unlikely to have an important effect on linear growth. Limited avai lable evidence does not allow us to conclude whether a combination of micro nutrients, with or without additional food, would have a greater impact tha n that seen with zinc alone.