[Vitamin E: physiology and pathology].

Abstract

The purpose of this report is to present an overview on vitamin E distribution, requirements, absorption and biochemical and nutritional aspects. A continuous interest in biochemical functions is recently developed and vitamin E certainly plays an important role throughout the body. The best known of its effects and still actively considered in recent years is the role as an important biological antioxidant. The red blood cell is an ideal model for studying the antioxidant role of vitamin E in cell membranes. Nutritional deprivation is a rare occurrence in developed countries. In prematurely delivered newborns the deficiency is due to marginal stores and to transient malabsorption but it can also be iatrogenic. In infants and adults vitamin E deficiency does occur in syndromes characterized by increased consumption or reduced absorption. Various gastrointestinal disorders induce, with steatorrhoea, marked alteration of vitamin E levels. Cystic fibrosis (CF), the commonest cause of pancreatic insufficiency during the first decades of life, is of particular interest. The fat malabsorption, often severe, may not well respond to pancreatic therapy and the hepatobiliary disease, increased in frequency with improved survival, induce a further reduction in intestinal bile salt concentration. Several manifestations have been attributed to vitamin E deficiency in CF and, although overt neurological complications seem to be relatively uncommon, it is recommended to maintain an adequate supplementation.