During the recent resurgence of interest in the clinical uses of
vitamin E, one of the major foci of attention has been the neurologic role of
vitamin E in humans. Studies in patients with secondary
vitamin E deficiency, caused by fat malabsorption disorders and
total parenteral nutrition lacking an adequate supply of
vitamin E, have elucidated a clinical disorder and histologic lesions of the nervous system and muscle that closely resemble those of experimental
vitamin-E-deficient animal models. Investigations of the primary form of human
vitamin E deficiency, the isolated
vitamin E deficiency syndrome, have further substantiated the relationship between
neurologic dysfunction and human
vitamin E deficiency. It is now clear that
vitamin E is an essential nutrient necessary for the optimal development and maintenance of the integrity and function of the human nervous system and skeletal muscle. The task for future study is to determine the mechanism by which
vitamin E deficiency causes degeneration of selective regions of the nervous system and to investigate possible benefits of
vitamin E supplementation in other
neurologic disorders. In addition, further study of the isolated
vitamin E deficiency syndrome promises to teach us more about normal physiologic mechanisms of
vitamin E absorption and transport in humans.