Researchers analyzed more than 10,000 questionnaires from men as part of a prostate cancer screening. More than 60 percent of the men said they took supplements, with 48 percent taking three or more.
Multivitamins, fish oil and vitamin C were the most common supplements that the men took. Three-hundred-thirty developed bladder cancer over the next five years.
Researchers concluded that that vitamins did not lower the odds of bladder cancer.
The findings are scheduled to be released next week at the annual meeting of the American Urological Association in San Francisco.