Pharmacology of vitamin E in the newborn.

The use of pharmacologic doses of vitamin E is distinctly different from nutritional vitamin E in regards to issues of efficacy and safety. Repeated administration of pharmacologic doses of vitamin E results in increasing concentrations of vitamin E in all tissues examined. The emergence of a toxic clinical syndrome associated with vitamin E therapy, the effects of vitamin E on important physiologic systems such as granulocyte function and the arachidonic acid cascade, the theoretic possibility of vitamin E becoming a prooxidant at high concentrations, and the continuing controversy regarding the efficacy of pharmacologic doses of vitamin E mandate further study of the dose-response nature of pharmacologic vitamin E therapy from both an efficacy and toxicity perspective.