A consumer advocacy group says it will sue Bayer Healthcare if it continues to claim its One A Day vitamins for men reduce the risk of prostate cancer.

The Center for Science in the Public Interest says the company's ubiquitous TV and radio ads misleadingly claim that a key ingredient of One A Day Men's Health Formula helps prevent cancer.

The group says the National Institutes of Health found no evidence the ingredient selenium prevents prostate cancer in men.

"The largest prostate cancer prevention trial has found that selenium is no more effective than a placebo," said David Schardt, the group's senior nutritionist. "Bayer is ripping people off when it suggests otherwise in these dishonest ads."

Bayer did not immediately return calls for comment.