Daily Multivitamin Linked to Slower Biological Aging in New Clinical Trial

Multivitamins may correct subtle nutrient insufficiencies that quietly undermine cellular aging processes.

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Most people who take a daily multivitamin couldn’t tell you exactly why—but their bodies might know.

A new clinical trial suggests that there may be something measurable behind the routine: Older adults who took a daily multivitamin for two years showed slightly slower biological aging—equivalent to about four months—particularly among those whose biological age appeared older than their chronological age at the start.

Daily Vitamin, Younger DNA?

Biological aging refers to how well the body’s systems function relative to a person’s chronological age. Scientists can estimate biological age by reading chemical tags on DNA that change in predictable patterns as we get older—a measure known as an epigenetic clock.

The study, published in Nature Medicine, examined whether daily multivitamins, containing a broad mix of essential vitamins and minerals, or cocoa extract supplements could influence biological aging.

Researchers analyzed data from 958 randomly selected healthy older adults with a mean age of 70 who participated in the COcoa Supplement and Multivitamin Outcomes Study (COSMOS), a large, ongoing randomized clinical trial in the United States designed to test the health effects of both multivitamins and cocoa flavanol supplements in older adults.

Participants were randomly assigned to one of four groups: multivitamins plus cocoa extract, multivitamins plus placebo cocoa extract, placebo multivitamins plus cocoa extract, or both placebos.

Researchers analyzed blood samples taken at the start of the study and again at one and two years in, tracking changes across five epigenetic clocks, two of which are linked to mortality risk.

Compared with participants taking a placebo, those taking multivitamins showed slower aging in two epigenetic clocks linked to mortality risk. The effect translated to about four months less biological aging over two years. The other three also showed trends toward slower aging but did not reach statistical significance.

Previous analyses from the COSMOS trial have also linked multivitamin use to other health benefits among older adults, including slowed age-related memory decline and reduced risks of certain cancers and eye diseases—suggesting that the effects observed in the trial may be part of a broader pattern.

“We have uncovered a key mechanism that may underlie the clinical findings of multivitamins for cognition, cancer, and cataracts,” Howard Sesso, associate director of the Division of Preventive Medicine in the Massachusetts General Hospital Department of Medicine and lead author of the study, told The Epoch Times.

The results are encouraging, he said, noting that the findings emerged from a randomized clinical trial, which is a more rigorous standard of evidence than observational research.

Why Multivitamins Might Work

Researchers do not yet know exactly why multivitamins appear to influence biological aging markers. However, the study authors suggest one possible explanation: Multivitamins may simply be correcting subtle nutrient insufficiencies that quietly undermine cellular processes involved in aging, including inflammation, oxidative stress, and DNA repair.

Jordan Glenn, head of science at SuppCo, a supplement-tracking app that helps users manage their daily vitamin and supplement intake, said that even modest improvements in biochemical pathways across multiple systems can translate into small shifts in biological aging markers.

Micronutrient deficiencies are relatively common in older adults, with many falling short of recommended levels of vitamins B12, D, and magnesium.

“The combination of vitamins, minerals, and bioactives in the multivitamin tested in the COSMOS trial may be greater than the sum of its individual parts,” Sesso said, suggesting that the nutrients may act together in complementary ways, “perhaps reflecting the importance of a healthy and diversified dietary pattern.”

Multivitamins are among the most widely used dietary supplements in the United States and are often taken to help fill these nutritional gaps.

What the Results Mean–and What They Don’t

The COSMOS trial result was critically important as a validation that epigenetic clocks were modifiable and responsive to interventions, according to Daniel Belsky, an associate professor of epidemiology at Columbia University’s Mailman School of Public Health, who co-wrote an accompanying commentary on the study. However, he urged caution about what that actually means.

“Epigenetic clocks are well validated as predictors of health span and lifespan in observational studies,“ he told The Epoch Times. ”But we have very little evidence that a change in the clocks leads to meaningful differences in health span.”

The effect size is also modest—about one-fifth the size typically considered a “small” effect in scientific studies and about five times smaller than the effect of calorie restriction seen in the CALERIE trial, a landmark study that tested whether eating significantly less could extend healthy lifespan. That comparison puts the multivitamin finding in perspective: real but not dramatic.

Still, both researchers noted that the cost-benefit calculation here is unusual. A daily multivitamin is cheap, safe, and asks almost nothing of the person taking it—a very different proposition from sustained calorie restriction.

“On a population level, it would be much easier to take a simple, cheap, safe multivitamin supplement,” Sesso said.

Participants whose biological age appeared older than their chronological age at the start of the trial showed the greatest benefit. However, researchers said some of the benefits may reflect statistical factors rather than a genuine biological response.

Epigenetic clocks are actually the right way to measure something like multivitamin supplementation, Belsky said.

“Vitamin supplementation isn’t designed to prevent a specific disease—it’s intended to broadly support the function and resilience of the whole organism,” he said.

“For those taking a daily multivitamin, there is no reason to stop,” Sesso said, noting that whether someone should take one is a decision best discussed with a health care provider in the context of a healthy diet, good lifestyle habits, and appropriate health screenings.