[Folates in human nutrition, Different clinical situations in which folate deficiencies exist].

The alimentary surveys carried out on various sectors of the population in industrialized countries have shown the existence of chronic clinically silent deficiency in micronutrients. In some cases, as in folates, their lability against conservation techniques, the change in alimentary habits, the abuse of alcohol and the great quantity of frequently used drugs which interfere in their absorption, diminish their content in the diet and their bio-availability. The appearance of macrocytic anemia is a late deficiency sign, and therefore in situations of an increase need and in patients included in the risk groups, a supplemental intake must be given in order to avoid irreversible lesions if it is not possible to monitor the folate levels. There are risk groups in which various etiological factors come into play, acting at a different metabolic level on the folates and making more difficult their dietetic or pharmacological compensation even if supply is considerably increased. We studied these factors independently and in each specific situation (old people, patients with liver disease, alcoholics, pregnant women and nursing mothers, neonates, children, malabsorption syndromes, gastrectomy, AIDS, anaesthesia and patients being treated with antifolic medication), evaluating their mechanisms of action and their potentiation in determined specific situations.