There’s a surprising amount of controversy surrounding something almost 40% of older Americans do every day: take a multivitamin.1 These supplements are marketed as health-boosting nutritional insurance policies—but some studies have found they don’t do much, beyond wasting consumers’ money.

New data only add to the back-and-forth. Researchers found that multivitamins may offer a small benefit for something that matters enormously with age: maintaining the ability to function well day-to-day.2

These findings are preliminary, as they haven’t yet been published in a peer-reviewed journal. But they add a new twist to the multivitamin debate, said Liron Sinvani, MD, a geriatrics and healthy aging physician with Northwell Health who was not involved in the new research.

“This is definitely interesting,” she told HEALTH. But “the jury’s still out.”

A Daily Multivitamin Was Linked to Better Function After 3 Years

The new research was presented at a conference in July 2026, but because it hasn’t been published in a peer-reviewed journal yet, its findings should be taken with a grain of salt for now.

The researchers used data originally collected for the COSMOS trial, through which more than 21,000 healthy older adults were randomly assigned to take a multivitamin, a cocoa supplement, both, or two placebos every day for several years. Researchers tracked their health to see whether people who took supplements had lower risks of developing cancer, heart disease, and other serious conditions.

The new study used data from the COSMOS trial to answer a different question: Whether taking a multivitamin affects “how people feel and function every day,” explained study co-author Bayu B. Bekele, PhD, a postdoctoral research fellow at the Georgia Prevention Institute of the Medical College of Georgia.

The answer? After three years, people taking multivitamins had better functional health than those taking placebos, with fewer health symptoms and better physical ability scores, the researchers found. Those differences could translate to slightly greater ease performing daily activities such as walking, climbing stairs, and doing chores.

How Big Was the Benefit?

Here’s the caveat: “The overall benefit was modest,” Bekele said—small enough that it might not be meaningful or noticeable, particularly among people who are generally healthy.

The findings were based on participants’ responses to a questionnaire meant to measure quality of life and physical function among people with heart failure.

Objective measurements would be more convincing than survey responses, especially since the survey might not translate perfectly to a general population without heart failure, Sinvani said. Previous research has shown that people taking multivitamins tend to report better health than those who don’t, even when their objective test results don’t back up their feelings.3

The results are “definitely positive and definitely exciting,” Sinvani said. But they don’t mean “now everybody should take a multivitamin, and don’t look back.”

This Isn’t the First Potential Healthy-Aging Benefit Seen With Multivitamins

Sinvani’s caution goes back to the years of scientific disagreement about multivitamins. Plenty of studies have found few, if any, benefits associated with using them.

The original COSMOS trial, for one, didn’t find reduced risks of cancer or cardiovascular problems associated with multivitamin use.45 Other studies also haven’t found meaningful benefits when it comes to lifespan, vision, and other health outcomes.67

“For the longest time, people were told multivitamins have no role,” said Jay Luthar, MD, a longevity-focused physician and instructor at Harvard Medical School who was not involved in the new study. But in recent years, Luthar told HEALTH, some studies have pointed toward potential benefits for older adults, specifically.

Earlier this year, another study using COSMOS data found that multivitamins might help slow biological aging. Older adults who take them also seem to be at lower risk of cognitive decline and memory problems than those who don’t, according to other COSMOS analyses.8

There’s still a lot of contradictory data out there, and more research is needed. But the new study fits into an emerging trend, Luthar said—one suggesting that multivitamins may have some part to play in healthy aging.

So, Should You Take a Multivitamin as You Get Older?

“There’s no official recommendation to take a multivitamin across the general population,” Sinvani noted.

She, like the National Institute on Aging, said it’s ideal to get needed nutrients from food. If that’s a struggle, though, she said a multivitamin might be worthwhile. Just look for one that doesn’t contain huge doses of particular nutrients, since overdoing it can be harmful, she said.

Luthar is even more open to older adults using multivitamins. “People want to feel well and be active and doing things independently” as they age, he said. Accumulating evidence suggests a multivitamin might help reach those goals.

The key word, though, is “help.” It’s “safe and reasonable” for older adults to take a multivitamin, but using one should “complement, not replace” medications and healthy lifestyle habits, Bekele emphasized.

Remember, a multivitamin is not a cure-all. Any benefits that these supplements provide are dwarfed by those of good nutrition, physical activity, sleep, social support, and staying up-to-date on recommended medical care. “You can’t even compare it,” Sinvani said.