Most experts agree that supplements add little, if anything, to a well-balanced diet.
Exercise, however, is proven to achieve the benefits claimed for vitamins, even for people who eat properly, reports the November 2007 issue of Harvard Men's Health Watch .
One leading reason people take vitamin supplements is to protect against cancer. But sadly, this strategy has been a flop. While studies continue on whether vitamin E and selenium can help reduce prostate cancer risk, data already show that beta carotene actually boosts the risk of lung cancer in smokers. And zinc, as well as high doses of folic acid, may also do more harm than good for men seeking to ward off prostate cancer. The bottom line: Supplements do not reduce cancer risk.
In addition, vitamins are not recommended for heart disease prevention. Trials of B vitamins have failed to demonstrate protection against heart disease. But people who eat fish twice a week enjoy a reduced risk of heart attack and sudden cardiac death. Leafy, green vegetables and whole grains also help protect against heart disease.