[Zinc deficiency and its functional implications].

The purpose of this article is to review theoretical aspects and research performed in Mexico suggesting the existence of marginal zinc deficiency in rural children and its consequences on health. Zinc is an indispensable nutrient for humans since it plays an important role in several metabolic pathways: it participates in the catalytic site of several enzymes, as a structural ion of biological membranes and is closely associated to protein synthesis, among other functions. It is therefore related to functional and health impairments, specially in children. A marginal deficiency of zinc in Mexican children is relevant because of its potential effects. Studies suggest that marginal zinc deficiency is associated to diets based on plant foods which are rich in zinc absorption inhibitors. Such diets are habitually consumed in rural areas and in poor areas of the cities. Marginal zinc deficiency was found to cause an increase in infectious diseases, specially diarrhea, and an impairment of the cognitive functions.