Oxidative stress is a putative factor in the pathogenesis of many human disorders of the central nervous system. Therefore, antioxidants such as vitamin E have become attractive as therapeutic agents in the treatment of several diseases. In addition, vitamin E seems to play a specific role in the nervous system. As a result, vitamin E has been used in pharmacologic doses in the treatment of disorders such as Parkinson disease, Alzheimer disease, and tardive dyskinesia.
One investigation showed that the use of 2000 IU all-rac-alpha-tocopheryl acetate is beneficial in the treatment of Alzheimer disease. Similar doses of vitamin E, however, were not beneficial for delaying the progression of Parkinson disease.
In other studies, dosages >/=400 IU vitamin E/d were found to be beneficial in the treatment of tardive dyskinesia, although this finding was not confirmed in a larger cooperative study conducted by the Veterans Administration. Even though the efficacy of vitamin E in the management of cardiovascular disease has been shown, the potential role of vitamin E in the treatment of cerebrovascular disease remains essentially unknown.
The experience from 2 large clinical trials involving the oral intake of 2000 IU vitamin E/d suggests that vitamin E is relatively safe at this dosage for periods <2 y.
However, the safety and efficacy of supplemental vitamin E over periods of many years in the prevention of neurologic diseases has not been adequately explored.
Source: Am J Clin Nutr 1999 Nov;70(5):793-801
(Research Service and GRECC, VA Medical Center, Minneapolis, and the Department of Psychiatry, University of Minnesota, Minneapolis.)