Large analysis finds that for healthy adults, taking multivitamins daily is not associated with a lower risk of death

A large analysis of data from nearly 400,000 healthy U.S. adults followed for more than 20 years has found no association between regular multivitamin use and lower risk of death. The study, "Multivitamin Use and Mortality Risk in 3 Prospective US Cohorts" led by researchers at the National Institutes of Health's National Cancer Institute, was published June 26, 2024, in JAMA Network Open.

Many adults in the United States take multivitamins with the hope of improving their health. However, the benefits and harms of regular multivitamin use remain unclear. Previous studies of multivitamin use and mortality have yielded mixed results and been limited by short follow-up times.

To more deeply explore the relationship between long-term regular multivitamin use and overall mortality and death from cardiovascular disease and cancer, the researchers analyzed data from three large, geographically diverse prospective studies involving a total of 390,124 U.S. adults who were followed for more than 20 years. The participants included in this analysis were generally healthy, with no history of cancer or other chronic diseases.

Because the study population was so large and included lengthy follow-up and extensive information on demographics and lifestyle factors, the researchers were able to mitigate the effects of possible biases that may have influenced the findings of other studies. For example, people who use multivitamins may have healthier lifestyles in general, and sicker patients may be more likely to increase their use of multivitamins.

The analysis showed that people who took daily multivitamins did not have a lower risk of death from any cause than people who took no multivitamins. There were also no differences in mortality from cancer, heart disease, or cerebrovascular diseases. The results were adjusted for factors such as race and ethnicity, education, and diet quality.

The researchers noted that it is important to evaluate multivitamin use and risk of death among different kinds of populations, such as those with documented nutritional deficiencies, as well as the potential impact of regular multivitamin use on other health conditions associated with aging.