High doses of vitamin E in the treatment of disorders of the central nervous system in the aged

Oxidative stress is a putative factor in the pathogenesis of many human dis orders of the central nervous system. Therefore, antioxidants such as vitam in E have become attractive as therapeutic agents in the treatment of sever al diseases. In addition, vitamin E seems to play a specific role in the ne rvous system. As a result, vitamin E has been used in pharmacologic doses i n the treatment of disorders such as Parkinson disease, Alzheimer disease, and tardive dyskinesia. One investigation showed that the use of 2000 IU al l-rac-alpha-tocopheryl acetate is beneficial in the treatment of Alzheimer disease. Similar doses of vitamin E, however, were not beneficial for delay ing the progression of Parkinson disease. In other studies, dosages greater than or equal to 400 IU vitamin E/d were found to be beneficial in the tre atment of tardive dyskinesia, although this finding was not confirmed in a larger cooperative study conducted by the Veterans Administration. Even tho ugh the efficacy of vitamin E in the management of cardiovascular disease h as been shown, the potential role of vitamin E in the treatment of cerebrov ascular disease remains essentially unknown. The experience from 2 large cl inical trials involving the oral intake of 2000 IU vitamin E/d suggests tha t vitamin E is relatively safe at this dosage for periods <2 y. However, th e safety and efficacy of supplemental vitamin E over periods of many years in the prevention of neurologic diseases has not been adequately explored.