Large daily doses of vitamin E, long touted as a virtual wonder drug that could protect against cancer, heart disease, dementia and other ailments, increase the risk for prostate cancer among middle-aged men, according to a large federal study released Tuesday. The analysis of data from more than 35,000 healthy men concluded that those who took vitamin E every day at the relatively large dose levels commonly sold in drug, grocery and health food stores were 17 percent more likely to develop prostate cancer.