JAMA study: Multivitamins don’t help people live longer

New population cohort research suggests that multivitamin users did not live any longer on average than their nonuser peers.   

The new study was published yesterday in JAMA Network Open Nutrition, Obesity and Exercise. It was the work of three researchers associated with the National Institutes of Health (NIH). 

Data lumped together from three large cohorts 

The authors analyzed data from three large population cohort studies that all began in the mid-1990s. After applying their exclusion criteria, the authors were left with data from more than 390,000 participants. Exclusion criteria included any diagnosed diseases, obesity or excessive caloric intake. 

The authors screened the data for multivitamin use, which included everything from monthly to daily use. The data was parceled into three buckets: nonusers, nondaily users and daily users of multivitamins. 

The daily multivitamin users were more likely to be women and college educated than their peers in the three cohorts. The daily multivitamin users were also slightly less likely to be smokers. 

Over the course of the follow up to the three population-based studies, more than 164,000 subjects died. (Many were older when first enrolled in the various groups, with media ages ranging from 42 to 62 years.) 

Authors: No evidence to support lifespan benefit from multivitamins 

Of the deaths, about 50,000 were attributed to cancer, another 35,000 died from heart diseases, about 9,000 died from cerebrovascular diseases, and the rest from unspecified causes. When parsing the data associated with the deaths, the authors said they could find no indication that multivitamins had helped any of the subjects to live longer than they might have otherwise. 

“We did not find evidence to support improved longevity among healthy adults who regularly take multivitamins,” the authors concluded. “However, we cannot preclude the possibility that daily MV use may be associated with other health outcomes related to aging.” 

A commentary on the study was also published on the same day as the research in the same JAMA journal. The authors of the commentary — three medical doctors from the U.S. and the Czech Republic — noted that vitamins have some very specific proven health benefits, such as preventing deficiency diseases like scurvy and beriberi.   

In addition, they said some vitamin products can help slow age-related macular decline, might be helpful in slowing cognitive decline and can benefit people who have had bariatric surgery. 

But overall, they said there is little support for use of multivitamins for general health support or as a prophylactic measure. 

“Considerable evidence now shows that, apart from the aforementioned roles for vitamin supplementation, there is little health rationale for the use of multivitamin supplements. Micronutrients come most healthfully from food sources,” the commentary authors wrote. 

CRN: Looking at mortality in isolation misses big picture 

Andrea Wong, Ph.D., senior vice president of the Council for Responsible Nutrition (CRN), said focusing just on mortality misses the point to some degree. Supplementation has long been aimed at increasing the number of years that people can enjoy good health, as opposed to merely making them live longer. 

“There is substantial evidence supporting the role of multivitamins in addressing nutritional needs, reducing the risk of specific diseases and health conditions, and supporting overall health,” Wong said in a CRN statement issued Wednesday. “Analyzing mortality rates in isolation fails to recognize the range of health benefits of multivitamin use identified in rigorous scientific studies, including the reduction of birth defects, reducing cancer risk, slowing cognitive decline, and many others.” 

In the statement, CRN noted that data from other large population-based studies can be used to make a convincing case for the importance of multivitamins in supporting health. 

“According to the National Health and Nutrition Examination Survey (NHANES), substantial percentages of the population fall short in their intake of vitamins A, C, D, E and K, as well as calcium, magnesium and potassium. In addition, the 2020-2025 Dietary Guidelines for Americans report that most people do not consume enough of certain nutrients such as vitamin D, calcium and potassium,” CRN added in the statement. 

NPA: Americans clearly fall short in micronutrients 

Daniel Fabricant, Ph.D, president and CEO of the Natural Products Association (NPA), said combining all the potential products that could be covered in the decades’ worth of data included in the study (with products undergoing reformulation from time to time) would tend to dilute the findings. 

“We don’t know the quality of the multivitamins. We don’t know what [consumers in the study] actually took,” he said. 

Fabricant noted that the recommendation in the study for people to get all their micronutrients from their diet makes sense on its face but seems out of step with the modern American food system. 

“We have lower soil quality, so the fruits and vegetables aren’t as good,” Fabricant said. “And no one argues that when looking at the standard American diet, we’re overfed and undernourished. Those two points alone would be enough for me to recommend a daily multivitamin.”