Can You Safely Get Vitamin D From the Sun?

A few minutes in the sun might have benefits, but risks include skin cancer, wrinkles and more

Kim Painter,

AARP

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En español

Published May 31, 2023

/ Updated April 29, 2024

woman with sun protection cream on her back in shape of sun sitting on the pool

Aleksej Sarifulin / Getty Images

If you eat well, it’s not hard to get enough of most vitamins. You can get plenty of vitamin C from all sorts of fruits and vegetables, vitamin E from leafy greens and nuts, and vitamin A from carrots and eggs.

“Vitamin D is different,” says Anastassios Pittas, M.D., a professor of medicine at the Tufts University School of Medicine in Boston. Because vitamin D is scarce in common foods, he says, Mother Nature provides a workaround: We produce our own vitamin D when our skin is exposed to sunlight. Many people could boost their blood levels, potentially protecting bones and getting other health benefits, by regularly exposing some unprotected skin to the sun.

But saying you could get your vitamin D that way isn’t the same as saying you should.

Most U.S. health authorities say the risks of skin cancer and skin aging outweigh the benefits of boosting sun exposure to get vitamin D. Groups including the U.S. Centers for Disease Control and Prevention, the National Cancer Institute and the American Academy of Dermatology say people should consistently use sunscreen, hats and sunglasses and should stay in the shade to protect themselves from the sun, especially at midday.

“If you expose yourself to the midday sun without sunscreen, yes, you can get your blood level of vitamin D quite high … but I don’t think the trade-off is good,” says JoAnn Manson, M.D., a professor of medicine at Harvard Medical School and the chief of preventive medicine at Brigham and Women’s Hospital in Boston. When you enjoy the outdoors safely, you still make some vitamin D, she says, and can get the rest from foods and supplements. (See Foods That Are High in Vitamin D.)

Manson helped write the vitamin D guidelines from the National Academy of Medicine (formerly the Institute of Medicine), a nonprofit advisory group. NAM guidelines say most people get some vitamin D from sun exposure, but they don’t recommend seeking it out. Instead, per the NAM, adults should use foods and supplements to get 600 international units of vitamin D daily up to age 70 and 800 IU daily after age 70. Food sources include salmon, canned light tuna and some mushrooms, along with fortified foods and drinks, such as milk and orange juice. Although it takes effort to get enough vitamin D from foods, supplements easily solve that problem, Manson says.

Some scientists say intentional sun exposure should be part of the mix. That’s common advice in the U.K., where public health agencies endorse the idea that a little regular sun exposure has benefits that balance with risks, says Ann Webb, a professor of atmospheric radiation at The University of Manchester in England. “You only need a short exposure for your vitamin D,” she says.

Pittas says that practice could be safely used in the United States. “When we think of sun exposure, we have been brainwashed, I am afraid, to only think of the bad effects,” he says. “But there are also benefits.” Those, he says, include not only vitamin D production but better mood and sleep.

“I think that the evolutionary appropriate way to obtain vitamin D is through our skin,” Pittas says.

The National Institutes of Health does not endorse intentional sun exposure, but it says older adults are at an increased risk for low vitamin D levels, partly because the skin’s ability to make vitamin D declines with age and older people spend more time indoors.

What’s a health-conscious person to do? Here are a few things to consider:

1. There’s no one-size sun prescription

Even scientists who endorse sun exposure can’t offer blanket advice on how much to get. That’s because skin tone, location, time of year, time of day, cloud cover, clothing and other factors play roles. In general, the lighter your skin and the closer you are to the equator, the faster you make vitamin D.

Webb says her research in the U.K. — farther north than any U.S. location — suggests that in the spring and summer, people with light skin who are wearing shorts, T-shirts and no sunscreen can get enough vitamin D with 10 to 15 minutes of midday sun on most days. People with dark skin need 25 to 40 minutes, she says, because the extra melanin that produces dark skin acts as a “natural sunscreen.”

For light-skinned people, the challenge is remembering to add sunscreen or clothing after a few minutes, she says. For dark-skinned people, the time commitment might be challenging. The payoff for many people, she says, could be storing up enough vitamin D to skip supplements, even in winter, when weak northern sunlight can’t trigger production.

Studies suggest that people vary greatly in how quickly vitamin D levels in their blood decline, over weeks and months, after effective sun exposure.

2. Sunscreen doesn’t block all vitamin D production … but windows do

Studies show that sunscreen use is not associated with low vitamin D levels, says Henry Lim, M.D., a dermatologist at Henry Ford Health in Detroit and a former president of the American Academy of Dermatology and American Dermatological Association. The likely reason: Most people don’t slather on enough to fully block the ultraviolet B rays that trigger vitamin D production, he says.

Rigorous use of recommended amounts of high-SPF sunscreen (a full ounce — enough to fill a shot glass — applied at least 15 minutes before heading outside) and other sun-protection measures could substantially limit vitamin D production, he acknowledges. But, Lim says, most people who spend time outside get at least a little vitamin D, even if they generally follow sun-safety advice. FYI: You won’t make any vitamin D sitting in front of a window. The UVB rays don’t get through the glass.

3. Sun damage is cumulative

Dermatologists who frown on unprotected sun exposure stress that the damage that can lead to skin cancer is cumulative. “Small amounts do add up,” says Elizabeth Hale, M.D., a clinical associate professor of dermatology at NYU Langone Medical Center in New York City and senior vice president of the nonprofit Skin Cancer Foundation. Cumulative sun exposure is closely associated with the most common skin cancers, basal cell carcinoma and squamous cell carcinoma, Lim says. Those cancers can be disfiguring or cause other problems if not caught and removed early.

The link between lifetime sun exposure and melanoma, a more deadly skin cancer, is not as clear, Lim says. But, he says, in light-skinned people, melanoma is clearly linked with multiple sunburns.

In the U.S., the lifetime risk for skin cancer is about 1 in 5; the risk of melanoma is 1 in 27 for men and 1 in 40 for women, according to the American Academy of Dermatology.

Cancer isn’t the only concern: Cumulative sun damage causes wrinkles, spotting, sagging and other signs of skin aging, dermatologists say.

4. Supplements are quite safe

Manson is the lead researcher on a study of nearly 26,000 healthy older adults, half of whom took 2,000 IU vitamin D supplements for an average of 5.3 years. “There were no appreciable side effects,” she says. Though findings on benefits have been mixed (see box), the supplements are so safe that people should feel comfortable taking 1,000 IU to 2,000 IU of vitamin D daily “as a form of insurance,” she says. People with some conditions might need higher doses but should take them under medical supervision, she says.

Multivitamins with 1,000 IU of vitamin D are a cheap, easy way to get enough, Lim says.

5. Indoor tanning is always a bad idea

Indoor tanning lights raise skin cancer risks without boosting vitamin D because they contain too little UVB, Lim and Hale say. “Indoor tanning is directly carcinogenic,” Hale says.

6. No one wants you to be a hermit

Pittas says too many people “are afraid of the sun” and lead sedentary indoor lifestyles.

No one is in favor of that. “I strongly encourage everyone, especially older adults, to have regular physical activity and to spend time outdoors,” Manson says. “I think that’s extremely important for good heart health, cognition and emotional well-being.” Wearing sunscreen doesn’t diminish those benefits, she says.

Why care about vitamin D?

Vitamin D helps your body absorb calcium and is crucial for strong bones, a healthy immune system and well-functioning muscles and nerves, says the National Institutes of Health. There’s some controversy about ideal vitamin D levels, but the National Academy of Medicine says most U.S. adults have adequate levels for bone health and can maintain them by consuming 600 to 800 international units daily.

Studies on higher-dose vitamin D supplements have produced mixed results. One large U.S. trial found no overall decrease in cancer, heart disease or even bone fractures when healthy older adults took 2,000 IU a day, says researcher JoAnn Manson, M.D. But the supplement takers were less likely to develop advanced cancer, die from cancer or develop autoimmune diseases such as rheumatoid arthritis or psoriasis. Researchers are looking at whether the vitamin can treat or prevent COVID-19. Pittas says it would be difficult to study whether intentional sun exposure would produce more benefits than supplements. “I wish I had those studies,” he says, but right now, “I don’t think there is any evidence to show daily exposure to the sun versus daily exposure to a supplement is any different.”

Studies targeting people at high risk for certain conditions may produce the most promising results, Pittas says. He led a study published in February 2023 that suggested high doses of vitamin D lowered the risk of diabetes in people with prediabetes.

Editor’s note: This story, first published May 31, 2023, has been updated to include new information.

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Kim Painter is a contributing writer who specializes in health and psychology. She frequently writes for AARP's Staying Sharp and previously worked as a health reporter and columnist at USA Today.

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