You've probably heard that exposure to the sun's ultraviolet radiation increases the risk for skin cancer. But did you know that a little bit of sunlight is good for you? The sun's UV rays stimulate vitamin D production in the skin. Vitamin D helps the body better absorb calcium, the building block for healthy bones.
If you have light skin, aim for 5 to 10 minutes of sunshine on your arms and legs two to three times a week without wearing any sunscreen, advises Dr. Michael F. Holick, a professor at Boston University's School of Medicine and director of the Vitamin D, Skin and Bone Research Laboratory. African-Americans or others with dark skin need 5 to 10 times as much sun exposure than those with lighter skin, because darker skin pigment is equivalent to a sunscreen with an SPF of 15.
Always wear sunscreen on your face, Holick adds.
During the winter, it's unlikely that Americans who live anywhere other than the southernmost states will be able to produce vitamin D through sun exposure. But you can easily make enough during the other seasons to fill up your vitamin D tank, Holick says. It doesn't matter whether you live in Alaska or by the equator, you can take advantage of the effects of sunlight on vitamin D production.
Getting plenty of vitamin D is good not only for the bones. Studies indicate it reduces the risk of numerous diseases, including type 1 diabetes, some common cancers, multiple sclerosis and rheumatoid arthritis.