Micronutrient deficiency in children

Malnutrition increases morbidity and mortality and affects physical growth and development, some of these effects resulting from specific micronutrien t deficiencies. While public health efforts must be targeted to improve die tary intakes in children through breast feeding and appropriate complementa ry feeding, there is a need for additional measures to increase the intake of certain micronutrients. Food-based approaches are regarded as the long-t erm strategy for improving nutrition, but for certain micronutrients, suppl ementation, be it to the general population or to high risk groups or as an adjunct to treatment must also be considered. Our understanding of the pre valence and consequences of iron, vitamin A and iodine deficiency in childr en and pregnant women has advanced considerably while there is still a need to generate more knowledge pertaining to many other micronutrients, includ ing zinc, selenium and many of the B-vitamins. For iron and vitamin A, the challenge is to improve the delivery to target populations. For disease pre vention and growth promotion, the need to deliver safe but effective amount s of micronutrients such as zinc to children and women of fertile age can b e determined only after data on deficiency prevalence becomes available and the studies on mortality reduction following supplementation are completed . Individual or multiple micronutrients must be used as an adjunct to treat ment of common infectious diseases and malnutrition only if the gains are s ubstantial and the safety window sufficiently wide. The available data for zinc are promising with regard to the prevention of diarrhea and pneumonia. It should be emphasized that there must be no displacement of important tr eatment such as ORS in acute diarrhea by adjunct therapy such as zinc. Cred ible policy making requires description of not only the clinical effects bu t also the underlying biological mechanisms. As findings of experimental st udies are not always feasible to extrapolate to humans, the biology of defi ciency as well as excess of micronutrients in humans must continue to be in vestigated with vigour.