UC HEALTH LINE: Sun's Rays Can Be Beneficial

CINCINNATI—For many people, the Memorial Day holiday marks the unofficial beginning of summer. Across the Tristate, families host holiday cookouts and neighborhood pools open their gates for kids and sunbathers alike.

But while the sun’s rays can be dangerous without proper skin protection, University of Cincinnati (UC) physician Nelson Watts, MD, says the sun has some benefits, too.

“Small doses of sunlight can help trigger vitamin D synthesis in the skin,” says Watts, professor in UC’s endocrinology, diabetes and metabolism division. “This is key for aiding in the absorption of calcium for our bones.”

Vitamin D is a fat-soluble vitamin found in some foods and can be made in your body after exposure to ultraviolet rays from the sun. It helps the body maintain normal blood levels of calcium and phosphorus and promotes calcium absorption to help form and maintain strong bones.

Watts, director of UC’s Bone Health and Osteoporosis Center, says insufficient levels of vitamin D can be dangerous, preventing bone tissue from hardening and even contributing to the development of several types of cancer, heart disease and diabetes.

Watts suggests taking caution to protect your skin from sun damage, but he says don’t avoid sunlight altogether.

But how much vitamin D do you need?

·       From birth to age 50, people should get 200 international units (IU) of vitamin D a day. You can get 200 IU, for example, from a can of tuna or two 8-ounce glasses of milk.

·       Adults ages 51 to 69 require 400 IU daily, and those over 70 require 600 IU.

·       Watts recommends that patients with osteoporosis get at least 800 to 1,000 IU of vitamin D daily.

·       To get the maximum benefit of vitamin D from the sun’s rays, Watts recommends 15 minutes of sun per day, three days a week, on the face, neck and arms.

“For people like me, who get up before sunup and put on sunblock first thing, a supplement of vitamin D is usually required,” says Watts.  “These are readily available without a prescription.”

It’s possible to get too much vitamin D. Watts says the safe “upper limit” is 2,000 IU daily, but he adds that it’s impossible to get vitamin D toxicity from sun exposure and toxicity from over-the-counter doses is unlikely.