What's True About Multivitamins?

12/04/07 Are multivitamins necessary? The April issue of Mayo Clinic Women's HealthSource answers this and other common questions about multivitamins.

While multivitamins can easily supply needed nutrients, a recent report from the National Institutes of Health says that not enough evidence exists to make a firm recommendation for or against the use of multivitamins for disease prevention.

Who needs a multivitamin?

The best source of needed nutrients is a balanced diet. Doctors continue to recommend multivitamins for people whose health conditions, dietary choices, lifestyle habits or medications impede their bodies' ability to get or absorb proper amounts of key nutrients from foods. For example, people over age 60 are often encouraged to take a multivitamin. Aging can make it more difficult for the body to absorb vitamins such as B-12, a nutrient that may reduce the risk of anemia, and vitamin D, which helps maintain bone strength.

What kind of multivitamin is best?

Inexpensive brands that offer the basics are as good as more expensive options. Labels should indicate that the multivitamin includes 100 percent of the Daily Value (DV) of most essential nutrients. Large doses (more than the label recommends) of nutrients and extras such as herbs, enzymes and amino acids should be avoided because of possible health risks.

Is iron necessary in a multivitamin?

For premenopausal women, multivitamins with iron can help replenish iron lost during menstruation. Following menopause, iron obtained through diet is usually sufficient.

Are other supplements needed, too?

Not necessarily, but there are exceptions. Most multivitamins don't provide the amount of calcium women need, especially during and after menopause when bone loss accelerates. After age 50, women should be getting 1,200 to 1,500 milligrams of calcium daily. Calcium is absorbed best when taken several times a day in amounts of 500 milligrams or less.

Women during childbearing years should check with their care provider about taking folic acid, which reduces the risk of spinal cord defects in developing fetuses.

Is input from a doctor needed?

Yes. Physicians need to know about vitamins and supplements their patients take because some may not be recommended with certain health conditions. A doctor also can advise when certain supplements could provide health benefits based on the patient's age, health and diet.