What you need, and how to get it ; Vitamins and minerals are essential to any diet, and research suggests that may help prevent cancer and heart disease, not to mention other health problems. But reality check: Many studies have been made on foods containing vitamin, but not necessarily supplements. In fact, if you eat a diet rich in fruits, vegetables and fortified foods, it is likely to get everything you need. But the supplements offer an easy insurance, just in case of health. Do you need? Here's a quick guide of beneficial nutrients and what they can do for you. Beta-carotene ; It is found in carrots, sweet potatoes and green peppers, among other foods, the antioxidant becomes the body to vitamin A and is important for good vision, immune system function, and good skin. However, the evidence is not really there to recommend to ward off cancer. In fact, a 2004 study found that supplements may actually increase the risk of lung cancer in s...