A few reports have suggested that certain vitamins protect against bladder cancer. However, new research indicates that the apparent anti-cancer effect disappears after accounting for a person's smoking history. In the current study, people with high levels of vitamins in their blood had a low risk of bladder cancer. As it turns out, however, these people were also the ones who rarely, if ever, smoked. Because smoking is a well-known risk factor for bladder cancer, it was probably their lack of smoking, not the high vitamin levels, that protected these people from cancer. The results, which are published in The Journal of Urology, are based on a study of 9345 men who had blood samples frozen when the study began and then were followed for more than 20 years to determine the rate of bladder cancer. During the study period, 111 men developed bladder cancer. The stored blood samples from these men and from 111 similar men without cancer were analyzed for several vitamins. Dr. Abraham M. Y. Nomura, from Kuakini Medical Center in Honolulu, and colleagues found that as blood levels of alpha-carotene, beta-carotene, lutein plus zeaxanthin, beta-cryptoxanthin, and total carotenoids rose, the risk of bladder cancer decreased. However, after accounting for how much a person smoked, none of the vitamin levels had much of an effect on bladder cancer risk, the team found.