Most people are able to meet their nutritional needs by eating a variety of nutrient-packed foods. While there is little evidence that the average person benefits from the daily use of a multivitamin-mineral supplement, there also is little evidence of harm from taking supplements that do not exceed 100% of recommended intakes of nutrients.

A multivitamin-mineral supplement may help to fill nutritional gaps in your diet. Don’t forget, however, that a multivitamin supplement is not a substitute for eating a balanced diet rich in unprocessed whole foods that are naturally full of thousands of potentially health-promoting substances that supplements don’t contain.

With a few exceptions, not enough evidence exists to recommend for or against the use of multivitamin-mineral supplements. That was the conclusion of a panel of experts convened by the U.S. government and reported in the Annals of Internal Medicine (Volume 145, page 364).

The experts reviewed data from well-designed trials that examined the use of multivitamin-mineral supplements in healthy adults. Overall, they found insufficient evidence that these multivitamin supplements offer benefits to the general population. Yet there were some data to suggest that supplements containing zinc and antioxidants slow the progression of age-related macular degeneration but only in those with a moderate form of this eye disease.

For individual supplements, the panel called the evidence "encouraging" for the bone density-building effects of calcium and vitamin D in postmenopausal women. They also found enough evidence to advise against the use of beta carotene in smokers, because of an increased risk of lung cancer.

But the firmest recommendations from the panel had to do with the need for better research on the benefits and composition of multivitamin-mineral supplements and the possible interactions they can have with medications. So for now, unless you have age-related macular degeneration or are at risk for or have low bone density, it's possible that taking a multivitamin-mineral supplement may offer no health benefits.