Vitamin E and neurological function: lessons from patients with abetalipoproteinaemia.

For many years the role of vitamin E (α-tocopherol) in human nutrition was uncertain, but it is now recognised that this fat soluble vitamin is necessary for normal neurological structure and function. The evidence came initially from patients with abetalipoproteinaemia, then from patients with other chronic and severe fat malabsorptive states, from patients with an isolated deficiency of vitamin E without generalised fat malabsorption, and from comparative neuropathological studies in vitamin E deficient man, monkey and rat. Severe and chronic vitamin E deficiency in the different patient groups resulted in a characteristic neurological disorder which progressed to crippling and blindness. Early and appropriate supplementation with vitamin E can prevent the development of all the neurological signs and symptoms, and treatment of patients with established lesions invariably halts and in some cases can reverse the neuropathy. These clinical and pathological findings raise a number of basic questions regarding the function of vitamin E in neural tissues which are currently being addressed in an animal model.