LINKEDINCOMMENTMORE

More than half of us take some sort of vitamin supplement, adding up to billions of dollars each year. But a new report confirms what some doctors have been saying all along: there's no evidence that supplements help prevent heart disease or cancer.

For many Americans, vitamins are a daily ritual. The reasons behind supplementation are as different as the people taking them, but now new research suggests if you're using them to prevent two major types of disease, you may not be getting your money's worth.

If the purpose of your vitamin supplementation is to prevent heart disease and cancer, that there isn't enough evidence right now to say conclusively that it is effective for doing that, said Dr. Kristen Bibbins-Domingo, U.S. Preventive Services Task Force panel member.

A new report from the U.S. Preventive Services Task Force updates its 2003 findings, stating there's still not enough evidence for or against supplementation for preventing heart disease and cancer.

This time there was enough evidence for experts to say without a doubt vitamin E and beta-carotene do not prevent these diseases. In fact, the report finds beta carotene can increase the risk for lung cancer among smokers.

This is one area where the studies are there and are clear that there are harms in this high risk group, said Dr. Bibbins-Domingo.

Representatives for the vitamin industry say many Americans rely on multivitamins, not for disease prevention but to make up for what they don't get from their diet.

A multivitamin can fill those nutrient gaps and provide us all the essential nutrients we need, said Douglas Mackay, ND, Council for Responsible Nutrition. It really is a good insurance policy.

Experts say patients should talk to their doctor about which supplements -- if any -- they should take.

Read or Share this story: http://www.king5.com/story/news/health/2014/08/05/13347764/