 That multivitamin in your medicine cabinet may not be doing a whole lot for you. Federal researchers looked into the health of thousands of people who took their vitamins over 20 years, trying to determine if they lower risks for things like heart disease or cancer. The NIH concluded that multivitamin use to improve longevity is not supported. The big caveat here, of course, some people do have vitamin deficiencies, so be sure to consult with your doctor before you stop taking any multivitamins or supplements. That's ABC's Ariel Reshev.