| By Brenda W. Lerner, RN, ALB |
Significant findings about vitamin supplements have been released within the past few months, and their publication has created some confusion about whether Americans who take a daily multivitamin should continue to do so. Soon after a new evidence report prepared for the U.S. Preventive Services Task Force (USPSTF) appeared in the journal JAMA in late June, media headlines such as “vitamins don’t work” and “vitamins are a waste of money” followed, leaving many to wonder if a supplemental vitamin is necessary, or even harmful.
The answer, as in most matters of health, lies in the details and with the particular situation of the person involved. I’ll try to clear up confusion about where the current evidence lies for vitamins as supplements in this post, along with the current expert recommendations for their use. The Gale Health and Wellness database also covers the important role of vitamins and minerals in supporting nutrition and health; see the Nutritional Supplements portal, or search for vitamins or a specific vitamin in the search box for more information.
The recent report was a meta-analysis of evidence from 84 of the latest clinical trials and studies on vitamin use among healthy adults. The analysis was conducted by a panel of independent experts who sought to determine the benefits or harms of using vitamins to prevent heart disease or cancer. Since 2014, the USPSTF has recommended against the use of vitamin E and beta carotene taken as a preventive measure against heart disease and cancer, and also considered available evidence as insufficient to know if a regular multivitamin supplement could offer any protective effects. The recent report was made to provide the USPSTF with the latest available evidence to inform their newer recommendations.
The analysis showed that for a healthy adult, vitamin supplements, including beta carotene, folic acid, calcium, magnesium, selenium, and zinc, as well as vitamins A, B, C, D, and E, or daily multivitamins, do not offer protection against developing heart disease, and they offer little to no benefit in preventing cancer. As for harms identified by the analysis, beta carotene supplementation was also associated with a small increase in the risk of lung cancer and death from heart disease, and vitamin A use could possibly increase the risk of bone fractures.
Based upon the expert panel’s conclusions, the USPSTF stated in June that current evidence remains insufficient to recommend the use of multivitamin supplements for the prevention of cardiovascular disease or cancer. The recommendations against beta carotene and vitamin E use for prevention also remain intact.
Where does this leave the healthy adult who takes a daily multivitamin? In most cases, they are left with little benefit against heart disease and cancer, and they’re missing the money they spent on the supplements. Hence, the terrible joke among health-care providers that says when healthy people take vitamin supplements, they make expensive urine. (Americans spent more than $40 billion on vitamins in 2021―mostly out of pocket, as they’re typically not covered by insurance.) Many experts agree, however, that it will do no harm to take a multivitamin 1) in formulations found over the counter and 2) when used according to directions on the label; and if this bit of perceived self-care leads to additional healthy habits, that’s good. But eating a well balanced, heart-healthy diet, along with exercise, is still among the most efficient preventive measures people can take to deter vitamin deficiencies, cancer, and heart disease.
These USPSTF recommendations do not apply to some groups who receive separate and specific recommendations for supplements, including infants, children, persons who can become pregnant, chronically ill persons, or persons with a nutritional deficiency. Anyone who is planning a pregnancy or could become pregnant, for example, should take a daily supplement containing 0.4 to 0.8 mg (400–800 micrograms) of folic acid daily, according to the USPSTF. Additionally, both children and adults with vitamin or nutritional deficiencies are recommended to take the specific vitamins or nutritional supplements identified by their health-care providers.
It’s also important to note that the potential benefits from vitamin supplementation for many other conditions were not evaluated in this particular analysis. There is mixed evidence, for example, that vitamins could help prevent cataracts, slow the progression of age-related macular degeneration, and delay the onset of cognitive impairment.
The USPSTF called for more longer-term studies on the role of vitamins in cancer and heart disease outcomes, especially for vitamin D, and also for more studies to learn if these results are repeated in specific populations, such as people who experience food insecurity or across ethnically diverse groups.
1. O’Connor, Elizabeth A., et al, “Vitamin and Mineral Supplements for the Primary Prevention of Cardiovascular Disease and Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force,” JAMA 327, no. 23 (June 21, 2022): 2334–2347.
2. U.S. Preventive Services Task Force. “Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer: Preventive Medication” Final Recommendation Statement. June 21, 2022.