Many adults take daily multivitamins in hopes of bettering their health. But a new study is calling their usefulness into question.

In the study, published in JAMA Network Open Wednesday, researchers analyzed data from nearly 400,000 healthy U.S. adults followed for more than 20 years and found no association between regular multivitamin use and lower risk of death.

The study was led by researchers from National Institutes of Health’s National Cancer Institute, who noted the participants studied were generally healthy, meaning more research is needed for populations with nutritional deficiencies.

“What we’re seeing is whether it’s death from cancer, from heart disease, from stroke, we’re not seeing a benefit from taking multivitamins,” Dr. Céline Gounder, CBS News medical contributor and editor-at-large for public health at KFF Health News, said of the study on “CBS Mornings” Thursday.

In general, it’s better to get vitamins from whole foods like fruits and vegetables, she added. But the potential benefits of taking a multivitamin also depend on the person.

“There are some people who are at risk for vitamin deficiencies, so people with chronic kidney disease, people who might not absorb vitamins because they’ve had bariatric surgery or because they have GI issues,” she said.

People who are pregnant, for example, should be taking a multivitamin with folate to prevent defects, Gounder said.

“There are certain populations where it makes sense, but not everybody,” she said.

In a statement to CBS News, the Council for Responsible Nutrition, a trade organization for vitamins, said the study fails to recognize the range of health benefits of multivitamin use.

Gounder noted the study looked only at risk of death, not other potential benefits.

“There is data, for example, that taking a multivitamin can reduce your cognitive decline as you get older, so your memory and so on. There’s also evidence, for example, macular degeneration, that you can head off with certain vitamins,” she explained. “So it depends on what you’re looking at. Are you looking at mortality, risk of death? Are you looking at certain other specific disease outcomes? I think that’s where, again, for certain populations, it may make sense to be taking a vitamin.”