[Hypovitaminosis A: epidemiology of a public health problem and strategies of its prevention and control].

Vitamin A deficiency occurs when body stores are low enough to result in adverse health consequences, even though there is no clinical sign observable, a situation that exists in parts of Latin America and The Caribbean. Deficient populations can be identified by using a combination of biological and ecological indicators. Such populations generally live under conditions of economic, social and ecologic deprivation where young children and women in their reproductive years are most vulnerable, particularly during periods of seasonal food shortage and of peak infection incidence. Sustainable preventive strategies are those that support changes in diet and conditions at the household level that increase the intake of vitamin A-containing foods in quality and quantity by the vulnerable groups and decrease the frequency they suffer infections. The use of vitamin A supplements in areas lacking clinical deficiency, such as in Latin America and The Caribbean, should be carefully considered (perhaps by targeting to high-risk groups) so as not to deter efforts to reach permanent solutions.