Use and safety of elevated dosages of vitamin E in adults.
Subjects with a variety of enteropathies, hemolytic anemias, acute respiratory distress syndrome, hepatitis, Gaucher's disease as well as those on TPN and hemodialysis, often have low ("deficient") blood levels of vitamin E. A deficiency of vitamin E can be manifested by accelerated red blood cell destruction and neuromuscular deficit. Supplementation of these patients may be advisable. Neurological dysfunction has been observed in adults with prolonged vitamin E deficiency resulting from lipid malabsorption. Long-term treatment with high doses of vitamin E results in improvement. Administration of 800 IU/day of vitamin E to subjects with G6PD deficiency, sickle-cell anemia and beta-thalassemia has resulted in improvement of hematological parameters. Supplementation with 300 IU/day for 3-6 months has resulted in improved walking distances and improved blood flow in patients with intermittent claudication. In a limited number of controlled studies, 300-600 IU/day resulted in improvement in premenstrual syndrome, tardive dyskinesia and also arthritis. Epidemiological studies suggest that high levels of serum vitamin E are associated with lower risk of certain cancers, cardiovascular disease and infections. In some cases the high levels are difficult to obtain by diet alone. High levels of vitamin E are contraindicated in subjects who are receiving vitamin K antagonists as anticoagulant therapy. Except for this interaction with vitamin K, there are no specific side effects associated with high doses of vitamin E. Thus, there are various reasons for supplementations with vitamin E and, with the exception noted, the risk of such supplementation is very low.
Machlin
L J
LJ
D000328:Adult; D006801:Humans; D014810:Vitamin E / Q000008:administration & dosage* / Q000633:toxicity
D014810:Vitamin E