Men taking multi-vitamin supplements often may increase their risk of death from prostate cancer, according to a new study published in the May 16 issue of the Journal of the National Cancer Institute.

But experts caution that the study could not establish a causal relation between the risk and use of multivitamins, meaning multivitamin use does not necessarily raise the death risk associated with prostate cancer.

The study, a statistical analysis, but not a trial, found that men who used multi-vitamins more than seven times a week were twice as likely to die of prostate cancer as men who never took vitamins.  

Those men were also at an increased risk of developing advanced or fatal prostate cancer, compared with men who never used multivitamins, reported Karla A. Lawson, Ph.D., of the National Cancer Institute and colleagues.

But apparently multivitamin use was not associated with increased risk of developing prostate cancer overall, the study found.

The study could not lead to any firm conclusion that taking vitamins definitely increases risk of men dying of prostate cancer.   The National Cancer Institute does not change any policy to tell men to stop using multivitamin supplements, according to news media reports.