Study finds vitamin and mineral supplementation may be counterproductive.

Although a healthy diet provides sufficient vitamins and minerals, many individuals take vitamin and mineral supplements hoping to further improve their health and prevent disease. A large, 19 year observational study of postmenopausal women has found that taking common vitamin supplements may actually shorten life instead. After controlling for confounders, absolute risk increased from 2.4% for multivitamins to 18% for copper.

PositiveTip: Supplements do not add to the benefits of eating fruits and vegetables, and may have unwanted consequences.

High selenium status increases risk of high cholesterol and diabetes.

Selenium, an essential element necessary for proper cellular function, has recently become a popular supplement thought to have antioxidant and anti-cancer properties. A new British study has linked high levels of selenium to increased levels of total cholesterol and LDL ("bad") cholesterol. The U.K. has lower selenium status that the U.S. making it a good place for a study like this. High selenium status has also recently been linked to a higher incidence of diabetes.

Excess folic acid may raise the risk of cancer.

There is increasing evidence that folic acid (FA) suppresses immune surveillance of cancer cells and may stimulate cancer cell growth. Earlier in 2009 it was reported that folic acid supplements were associated with excess risk of prostate cancer.