Be Tenacious About Soaking Up Vitamin D
Even in an age of fortified milk and cereal, some doctors worry that we're short on vitamin D--to our detriment.
Historically, most people have gotten their quota from the sun, which stimulates the cells in the skin to produce it. But now that we're either slathered in sunscreen or parked in front of the computer, vitamin D deficiency appears to be fairly common. One study in Boston found that of 307 adolescents tested, 75 were vitamin D deficient. African-American kids were more likely to be low, since the pigment in dark skin acts as a sunblock.
The National Academy of Sciences' Institute of Medicine currently recommends that adults get 200 international units, or IU s, a day of vitamin D, which the body needs to absorb calcium. But some scientists argue for even more, since studies now suggest that extra might help prevent fractures in elderly people and that a shortage could even play a role in cancer, type 1 diabetes, and multiple sclerosis.
Most light-skinned people can get enough sun in just a few minutes a day outdoors without sunscreen. But that might not do it for people who live farther north or who have darker skin. And even short periods without protection make dermatologists nervous; such exposure may increase your risk of skin cancer. Endocrinologist Bess Dawson-Hughes, a professor at Tufts University, recommends supplements to her patients, for a total of 1,000 IU s a day. Don't go overboard--too much D can be toxic.
This story appears in the December 26, 2005 print edition of U.S. News & World Report.