Why You Should Move Your Workout Outdoors

February 13, 2013

Winter blues are reason enough to seek out the sun. But here’s another: People with adequate levels of vitamin D—produced when your skin is exposed to the sun’s rays—have about half the risk of developing type 1 diabetes, according to a new study in the American Journal of Epidemiology.

Unlike type 2 diabetes, which is linked to obesity, type 1 is an autoimmune disorder. (Though it was once called juvenile-onset diabetes, actually develops in adults about 60 percent of the time.) If you have it, your body destroys the beta cells in your pancreas that produce insulin. But the new research suggests the sunshine vitamin may interfere to save those cells. “Vitamin D can decrease the immune response that supports the development of autoimmunity, and may protect the insulin-producing cells from death,” says study author Kassandra Munger, Ph.D., of the Harvard School of Public Health.

It’s too soon to recommend vitamin D supplements as a way to prevent type 1 diabetes. “However, there is a great deal of evidence suggesting that having adequate vitamin D levels is important to overall health,” Munger says.

You can get vitamin D in fortified milk, eggs, and fatty fish, in addition to brief exposure to sunlight (about 10 minutes daily can do the trick). But if you have darker skin or regularly cover up in the sun, your levels are more likely to be low, Munger says; consider asking your doctor for a vitamin D test. “For most people, dietary intake of 1,000 to 4,000 IU per day—easily achieved by supplement use—will increase their vitamin D levels into the adequate range,” she says.