Choosing and using supplements

If you decide to take a vitamin or mineral supplement, consider these factors:

  • Check the label. Read labels carefully. Product labels can tell you what the active ingredient or ingredients are, which nutrients are included, the serving size — for example, capsule, packet or teaspoonful — and the amount of nutrients in each serving.
  • Avoid megadoses. In general, choose a multivitamin-mineral supplement that provides about 100 percent of the Daily Value (DV) of all the vitamins and minerals, rather than one which has, for example, 500 percent of the DV for one vitamin and only 20 percent of the DV for another.
  • Check expiration dates. Dietary supplements can lose potency over time, especially in hot and humid climates. If a supplement doesn't have an expiration date, don't buy it. If your supplements have expired, discard them.
  • Watch what you eat. Vitamins and minerals are being added to a growing number of foods, including breakfast cereals and beverages. If you're also taking supplements, you may be getting more than you realize of certain nutrients. Taking more than you need is expensive and can raise your risk of side effects. For example, too much iron can cause nausea and vomiting and may damage the liver and other organs.

Keep up with supplement safety alerts

The Food and Drug Administration (FDA) keeps a list of dietary supplements that are under regulatory review or that have been reported to cause adverse effects. If you're taking a supplement, it's a good idea to check the FDA website periodically for updates.

Oct. 18, 2014 See more In-depth