The Effect of Vitamin Deficiencies (E and A) and Supplementation on Infection and Immune Response

Nutritional deficiencies contribute to the high incidence of morbidity and mortality from infectious diseases among children in developing countries. Infectious diseases (respiratory and diarrheal) are among the leading causes of death in children around the world. Deficiencies of vitamins E and A have been shown, in animal models and in humans, to impair the immune response and to decrease host resistance to infectious diseases. Furthermore, supplementation with higher than recommended levels of these nutrients in some, but not all cases, was associated with improved immune response and resistance to certain bacterial and viral infections. Several comprehensive reviews have been written on the role of vitamins E and A in the regulation of the immune response. This chapter, therefore, is not intended to be comprehensive; rather, it is a brief summary of past work, with emphasis on recent findings.