Do Vitamins Help Protect Against Disease?
Nearly one third of all Americans take a multi-vitamin supplement daily, but according to three major studies conducted at Brigham and Women’s Hospital and published in 2008, certain vitamins offer no protection against cancer and cardiovascular disease.
It was previously thought that these vitamins may play a role in disease prevention because of an antioxidant benefit. However, researchers who were studying Vitamin E, C, B6, B12 and folic acid, found that these vitamins failed to protect against two chronic diseases that affect millions of Americans and large doses of some vitamins could potentially carry additional risks.
“Conclusive proof that vitamins reduce cancer or cardiovascular disease requires large-scale randomized trials,” says JoAnn Manson, MD, DrPH, chief of Preventive Medicine at BWH. “In the past several months, researchers at BWH have shown in three separate trials that there is no magic vitamin pill that will reduce the risk of these diseases,” she said. "While Vitamin D looks promising in the prevention of cancer, large randomized trials are still needed."
Researchers studied the effects on Vitamin C and E in more than 14,000 middle-aged men during an eight-year period. They found that men who took the vitamins had no difference in either cancer rates or cardiovascular disease rates compared to men who did not take the vitamins.
In a separate study, researchers looked at more than 5,000 middle-aged women who took vitamin B6, B12 and folic acid supplements during a seven-year period and also found no reduction in cancer risk for women who took the vitamins when compared to women who took a placebo pill.
“People should continue to focus on eating a healthy diet and exercising regularly,” said Howard D. Sesso, Sc.D., M.P.H., project director of the Physicians Health Study II in the Division of Preventive Medicine at BWH and lead author of one of the studies.
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