22 Strange Ways the Sun May Affect Your Body

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You know that the sun’s ultraviolet (UV) rays can cause skin cancer and premature aging, and that wearing sunscreen is an important way to protect yourself. But research has shown that sunlight also seems to affect health in a lot of other ways, both positively and negatively.

Strange Ways the Sun May Affect Your Body

“One American dies every hour from skin cancer, and the overwhelming majority of these cancers are caused by overexposure to UV light—there’s no question about that,” says Darrell Rigel, MD, clinical professor of dermatology at New York University Langone Medical Center. “But that doesn’t mean you should stay inside all day or that there aren’t plenty of health benefits to being outdoors. You just have to balance everything and use common sense to protect yourself.” Here’s what you need to know so you can make smart choices when you step outside.


Sunlight triggers the release of the feel-good brain chemicals serotonin, so spending time outdoors has been shown to boost mood and relieve stress. And for some people, not getting enough sun during winter months can even trigger a type of depression known as seasonal-affective disorder. (Note: In rare cases, sunlight can trigger depression.)

sun exposure

Luckily, you can fight the effects of SAD, or even a bad mood, without exposing yourself to harmful UV rays, says Dr. Rigel. “You don’t need ultraviolet light to feel better, you just need visible light,” he says. “Just being in a bright room can help.” Special light boxes, which don’t give off UV rays, may also help.

Vitamin D levels

Sunlight helps the body make vitamin D—an important nutrient for healthy bones, brains, and more. Vitamin D is found naturally in very few food sources, so people need to get it either from sun exposure, supplements, or fortified foods, like milk. (Fatty fish, such as salmon, naturally contain vitamin D.)

Sun exposure vitamin D

You don’t need much sunlight to get adequate vitamin D, especially if you have pale skin or red hair; for most people, just 5 to 30 minutes twice a week, with your face, arms, legs, or back exposed without sunscreen is enough. But still, many Americans don’t get enough. And because of very real skin-cancer concerns, the American Academy of Dermatology recommends getting your vitamin D from a healthy diet and/or supplements—not from the unprotected sun exposure.

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