Dietary supplements aren't intended to be a food substitute because they can't replicate all of the nutrients and benefits of whole foods, such as fruits and vegetables. So if you're generally healthy and eat a balanced diet, daily dietary supplements may not be worth the expense. However, if you can't eat enough healthy foods or have certain conditions, you may benefit from taking a daily dietary supplement
Whole foods: Your best source of micronutrients
Whole foods are your best sources of vitamins and minerals. They offer three main benefits over dietary supplements:
- Greater nutrition. Whole foods are complex, containing a variety of the micronutrients your body needs — not just one. An orange, for example, provides vitamin C plus some beta carotene, calcium and other nutrients. A vitamin C supplement lacks these other micronutrients.
- Essential fiber. Whole foods provide dietary fiber. Fiber, as part of a healthy diet, can help prevent certain diseases, such as type 2 diabetes and heart disease, and it can also help manage constipation.
- Protective substances. Whole foods contain other substances recognized as important for good health. Fruits and vegetables, for example, contain naturally occurring food substances called phytochemicals, which may help protect you against cancer, heart disease, diabetes and high blood pressure. Many are also good sources of antioxidants — substances that slow down oxidation, a natural process that leads to cell and tissue damage.
Who needs dietary supplements?
If you're generally healthy and eat a wide variety of foods, including fruits, vegetables, whole grains, legumes, low-fat dairy products, lean meats and fish, you likely don't need dietary supplements.
However, if you can't eat enough healthy foods, you may benefit from taking a daily dietary supplement. Dietary supplements may be appropriate if you:
- Don't eat well or consume less than 1,600 calories a day
- Are a vegan or a vegetarian who eats a limited variety of foods
- Are pregnant, trying to get pregnant or breast-feeding
- Are a woman who experiences heavy bleeding during your menstrual period
- Are a postmenopausal woman
- Have a medical condition that affects how your body absorbs, uses or excretes nutrients, such as chronic diarrhea, food allergies, food intolerance or a disease of the liver, gallbladder, intestines or pancreas
- Have had surgery on your digestive tract and are not able to digest and absorb nutrients properly
Talk to your doctor or a dietitian about which supplements and what doses might be appropriate for you. Be sure to ask about possible side effects and interactions with other medications.
Choosing and using dietary supplements
If you decide to take a vitamin or mineral supplement, consider these tips:
- Check the supplement 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 supplements that provide 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. The exception to this is calcium. You may notice that calcium-containing supplements don't provide 100 percent of the DV. If they did, the tablets would be too large to swallow.
- Look for USP on the label. This ensures that the supplement meets the standards for strength, purity, disintegration and dissolution established by the testing organization U.S. Pharmacopeia (USP).
- 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.
- Store all vitamin and mineral supplements safely. Put supplements in a locked cabinet or other secure location out of children's reach. Don't leave supplements on the counter or rely on child-resistant packaging. Store dietary supplements in a dry, cool place. Avoid hot, humid storage locations, such as in the bathroom.
- Check alerts and advisories. The Food and Drug Administration keeps a list of dietary supplements that are under regulatory review or that have been reported to cause adverse effects. Check its website periodically for updates.
Last Updated: 2010-06-05