Supplements: Nutrition in a pill?

Supplements aren't for everyone, but older adults and others may benefit from specific supplements. By Mayo Clinic Staff

The Dietary Guidelines for Americans make it clear that your nutritional needs should be met primarily through your diet. For some people, however, supplements may be a useful way to get nutrients they might otherwise be lacking. But before you go shopping for supplements, get the facts on what they will and won't do for you.

Supplements vs. whole foods

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 depending on your situation and your eating habits, dietary supplements may not be worth the expense.

Whole foods 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, such as whole grains, fruits, vegetables and legumes, provide dietary fiber. Most high-fiber foods are also packed with other essential nutrients. 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 important for good health. Fruits and vegetables, for example, contain naturally occurring 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 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 supplements.

However, the dietary guidelines recommend supplements — or fortified foods — in the following situations:

  • Women who may become pregnant should get 400 micrograms a day of folic acid from fortified foods or supplements, in addition to eating foods that naturally contain folate.
  • Women who are pregnant should take a prenatal vitamin that includes iron or a separate iron supplement.
  • Adults age 50 or older should eat foods fortified with vitamin B-12, such as fortified cereals, or take a multivitamin that contains B-12 or a separate B-12 supplement.

Dietary supplements also 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 a woman who experiences heavy bleeding during your menstrual period
  • Have a medical condition that affects how your body absorbs or uses 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 any medications you take.

Jan. 19, 2013 See more In-depth