Multivitamin users experienced 19% more breast cancers.

Can "nutritional insurance" in the form of taking multivitamin supplements actually increase the risk of breast cancer? Swedish investigators followed more than 35,000 older women (49-083 at the beginning) for an average of 10 years, and discovered that after adjusting for known risk factors, the multivitamin users were 19% more likely to develop breast cancer. While this observational study cannot determine cause-and-effect, the authors indicate it is certainly biologically plausible.

PositiveTip: If you eat a healthy and varied diet there is really no need to take multivitamins.