Long-Term Daily Multivitamin Use Does Not Extend Lifespan, Study Finds

Researchers found those taking a daily multivitamin actually have a 4% greater risk of death than those who do not take them.

Many consumers have been led to believe that taking a multivitamin supplement every day will help improve their health, and potentially lead to a longer life. However, the findings of a new study raises serious questions about the benefits of multivitamins, suggesting that daily users may actually be more likely to die.

About a third of all Americans report taking multivitamins, which are dietary supplements meant to provide a daily supply of various vitamins when consumers cannot get adequate levels from their diet.

There is no standard formulation for multivitamins, and each manufacturer decides what to put in their specific products, as well as where to source the ingredients. In addition, the products are sold in a variety of different forms, including tablets, capsules, powders, and liquids.

Unlike prescription medications and medical devices, the U.S. Food and Drug Administration (FDA) does not have the authority to regulate dietary supplements in the United States. Therefore, the agency does not approve supplements to determine they are safe before they are sold, and it does not review ingredients to ensure products contain what is listed on the label.

Multivitamin use began to decline in 2022, after the U.S. Preventive Services Task Force reviewed data on multivitamin supplementation and death, and found that there was not enough evidence to conclusively determine whether taking the supplements reduces or increase the risk of death.

In new findings published this week in the medical journal JAMA Network Open, researchers from the National Cancer Institute at the National Institute of Health examined data from three different study groups to evaluate the actual benefits provided by multivitamins, concluding that daily use does not help prevent death from cancer, cardiovascular disease, or other diseases.

A team of researchers, led by Dr. Erikka Loftfield, examined data on 390,000 healthy adults with no history of cancer or other chronic diseases. Data was taken from three prospective studies in the United States from 1993 to 2001, including the National Institutes of Health-AARP Diet and Health Study, the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, and the Agricultural Health Study. Patients were followed up for 20 or more years.

After analyzing the data, Loftfield’s team found no evidence linking regular multivitamin use to a reduced risk of death from major causes of death like heart disease, cancer, or cerebrovascular disease. In fact, there was no sign that multivitamin use decreased the risk of death from any cause and may potentially increase the risk of death.

“In this cohort study of 390 124 generally healthy US adults with more than 20 years of follow-up, daily MV (multivitamin) use was not associated with a mortality benefit,” Lottfield’s team concluded. “In contrast, we found that daily MV use vs nonuse was associated with 4% higher mortality risk.”

The researchers concluded that while taking multivitamins does not conclusively lead to any harm to humans, the best way to get sufficient vitamins is to get them from food sources instead of supplements. They recommend eating a well-balanced diet with enough fruits and vegetables to provide vitamins.