Washington - In a letter sent to Bayer by The Center for Science in the Public Interest, the advocacy group is threatening to sue the drug maker unless they stop making claims that their vitamins for men reduce prostate cancer risk.

According to the group, the vitamins do not prevent prostate cancer, therefore Bayer should not be advertising this as a benefit to the pills.

According to Bayer, the FDA have backed the claims on their vitamins when they approved them for sale in the U.S.

The advertising is working, as last year the company reported more than 190 million dollars of sales of the vitamins.

Evidence appears to back the alligation of false advertising as a recent study performed by the National Institutes of Health found no benefit to ingesting selenium when it came to reducing risk of men developing prostate cancer.

The mens vitamins contain selenium, and it is because of this that Bayer is marketing them as prostate cancer risk reducers.