Your body needs vitamins and minerals to perform essential functions, grow and develop, and repair itself. Research on whether they prevent cancer continues, with mixed results. Some vitamins, minerals, and other nutrients help protect your body against damage from oxidants.
In a laboratory study, selenium supplements did not prevent a second skin cancer in people who already had the disease. But it did lower the new cases of prostate, lung, and colorectal cancers. In some studies, selenium has been linked to an increased risk for diabetes. So be cautious about considering supplements that contain selenium.