Do You Need a Vitamin D Supplement?

They aren't necessary for everyone

By Janet Lee

November 2, 2022

rows of vitamin D capsules on pink background

Chances are you have a bottle of vitamin D pills sitting on your kitchen counter or in your medicine cabinet right now. Your doctor may have recommended you take them to help improve bone health, lower your risk of falling, and even reduce the likelihood of cancer, heart disease, or respiratory problems (including those caused by COVID-19). In recent years, vitamin D supplements and testing have become “a billion-dollar industry,” says Pinchas Cohen, MD, dean of the USC Leonard Davis School of Gerontology in Los Angeles.

But while you definitely need enough of the nutrient—600 IU between the ages of 51 and 70, and 800 IU for those over 70—for calcium absorption, fighting inflammation, and more, new research is finding that supplements may not be warranted.

Looking at the Research

The focus on vitamin D began in the early 2000s, when a large study published in the Archives of Internal Medicine found that rates of vitamin D deficiency in the U.S. had tripled. “Many chronic conditions, particularly diseases of aging ... are linked with lower levels of vitamin D in the blood,” Cohen says.

Several studies showed a connection between vitamin D and an increased risk for a variety of health problems, but they were observational, meaning experts couldn’t say for certain that being low in D caused those conditions or that supplements lowered the risk. In fact, it could be that the conditions themselves contributed to the low levels. Newer, controlled studies—where researchers randomly assign people to take vitamin D supplements or a placebo and track differences in the risk of getting a condition (or worsening one) between the groups—haven’t found benefits from taking vitamin D.

The largest of these is the VITAL study, which followed 25,871 men and women ages 50 and older for about five years. During that time, the participants took 2,000 IU of vitamin D a day or a placebo. The first results, published in 2018, found that those who were taking vitamin D didn’t have a lower risk of cardiovascular disease or cancer compared with those taking the placebo.

A subsequent VITAL report, published in July in The New England Journal of Medicine, found that supplements didn’t protect against fractures. “Age, sex, and race didn’t modify the outcomes,” says the lead author, Meryl LeBoff, MD, director of the Skeletal Health and Osteoporosis Center and Bone Density Unit at Brigham and Women’s Hospital in Boston. “We’re rethinking recommending vitamin D for bone health in generally healthy midlife adults. It’s a paradigm shift.”

In three studies published in September that looked at frailty and respiratory infections, researchers got similar results. (Frailty is an age-related decline in functioning that causes fatigue and increases the chances of a variety of health problems.) Taking vitamin D didn’t prevent frailty or keep it from worsening, according to a study in JAMA Network Open, even in people who started out with low levels and saw them increase. And two studies published in The BMJ found that D supplements had no effect on the risk of getting a respiratory infection or COVID-19.

The bottom line: “None of the common chronic diseases of aging seem to benefit from taking vitamin D,” Cohen says.

What to Do Now

While it may not be as easy as taking a pill, experts say that most people will get more protection against chronic conditions of aging by making lifestyle changes. Start by exercising regularly and eating a Mediterranean diet that includes good sources of vitamin D—eggs, salmon, tuna—and D-fortified foods such as milk or milk substitutes and certain cereals.

There’s no harm in taking 600 to 800 IU of vitamin D in supplement form daily, experts say, but this latest evidence suggests you probably don’t need to spend the money. Generally speaking, healthy people appear to get all the vitamin D they need from their diet and being outdoors, because sunlight on skin triggers the body’s production of the vitamin. Still, it’s important to check with your doctor because people with osteoporosis and those 75 and older may need a supplement.

Editor’s Note: A version of this article also appeared in the December 2022 issue of Consumer Reports On Health.

Janet Lee

Janet Lee, LAc, is an acupuncturist and a freelance writer in Kansas who contributes to Consumer Reports on a range of health-related topics. She has been covering health, fitness, and nutrition for the past 25 years as a writer and editor. She's certified by the National Academy of Sports Medicine and Yoga Alliance, and is a trained Spinning instructor.