Multivitamins may do more harm than good, new research warns

More than half of Americans regularly take multivitamins. Yet new research suggests these supplements may offer little benefit and could even pose risks for some groups. Health experts are now urging caution over their use. A multivitamin combines various vitamins and minerals into a single pill. However, the U.S. Preventive Services Task Force has found no clear evidence that these supplements prevent cancer or heart disease.

For men, the supplements do not reduce the risk of common cancers or death from cancer. Men aged 65 or older also gain no cognitive benefits from taking them.

For women, multivitamins do not extend life and may slightly increase the risk of early death. Some studies link certain dietary supplements to higher mortality in older women. Calcium supplements, in particular, may raise the risk of heart attacks in some individuals.

Pregnant women must be careful with high vitamin A intake, as it can cause birth defects. Smokers or former smokers should avoid multivitamins with high levels of beta-carotene and vitamin A, due to a higher risk of lung cancer. The U.S. Preventive Services Task Force states there is not enough evidence to support benefits from vitamin and mineral supplements for preventing major diseases. While some groups face specific risks, the general population may not gain the health improvements they expect from multivitamins.