Calcium combined with vitamin D is known to benefit bones, and it's among the supplements worth considering, according to Consumer Reports ShopSmart. Other beneficial supplements include fish oil, with omega-3 fatty acids, and folic acid, for women who are pregnant or are planning to become pregnant.
But ShopSmart says there are other vitamins and supplements that anyone who's healthy should skip, including vitamin A and even multivitamins. Research shows that multivitamins don't benefit most people's health. They don't, for example, decrease the risk of heart disease or cancer.
Another vitamin warning: Don't take more than your doctor says you need. Megadoses can be dangerous. Too much vitamin E has been linked to a small but increased risk of lung cancer over time. And very high doses of vitamin D could damage kidneys. ShopSmart says that it's easier than you think to take too much. Pay attention to the dosage of each vitamin or supplement that you take, and go over the information with your doctor. And don't forget to factor in vitamin-enriched food and drinks.
Also, don't substitute supplements for the real thing. Centrum has a new ProNutrients Fruit & Veggie supplement. But on the back it says it's "not intended to replace your daily intake of fruit and vegetables."
ShopSmart has another caution about supplements: Combining them with prescription drugs can be dangerous. For example, there's evidence that vitamin C reduces the power of many chemotherapy drugs. And St. John's wort can interfere with some birth control. It's always a good idea to talk to your doctor about any vitamins or supplements you're taking.