Experts at Fred Hutchinson Cancer Research Center studied data from over 160,000 women who were followed for at least eight years. Of those women, just over 40 percent reported daily vitamin use.
They found no difference in cancer rates between women who took supplements and those who didn't. Supplement users also had the same rates of heart disease and death.
Experts say getting nutrients from food may be the best way a woman can lower her risk for disease.
A representative from The Council For Responsible Nutrition, a supplement industry group, says multivitamins are meant to be used as part of a healthy lifestyle, not as magic bullets that assure the prevention of chronic diseases.