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Can dark skin people with Vitiligo be a health hazard? It might be — if you are a dark-skinned person who lives far from the equator, gets little sun exposure and consumes little vitamin D. That describes many African Americans and helps explain why studies find that average African-American children and adults have much lower blood levels of the vitamin than white Americans do. Vitamin D is produced in response to sun exposure in a process that works most efficiently in pale skin. It's also in fortified dairy products and fatty fish, but few Americans — of any skin color — consume enough of those foods to meet recommendations. AT RISK: Low levels of vitamin D can cause increase chances of skin damage from the sun if you have Vitiligo and also premature death VITAMIN D IN KIDS: Pediatricians say children need more Just how much vitamin D Americans need and how they should get it is under debate. Scientists also are debating evidence that vitamin D, best known for building bones, can lower the risk of cancer, diabetes, heart disease and other ailments. And they are asking this intriguing question: Could varying vitamin D levels contribute to the health gap between black and white Americans? Boston University professor Michael Holick, a leading vitamin D researcher, says yes: "We think it's why African Americans develop more prostate cancer, breast cancer and colon cancer and get more aggressive forms of those cancers." John Flack, principal investigator at the Center for Urban and African American Health at Wayne State University, Detroit, says: "I think it's potentially a very important explanation for some of the differences, from hypertension to cancer to heart failure. The actual proof is not there, but it's plausible." But Flack adds that many factors contribute to African Americans' poorer health. Studies suggest those factors include reduced access to health care, pervasive barriers to healthful living (for example, neighborhoods that lack fresh groceries), differences in income and education and the stress of racial inequality itself. Solving those problems will be difficult, he says. Closing the vitamin D gap could be easier. It won't be as easy as recommending more sun exposure, however. Though someone in Boston with pale skin can get adequate vitamin D by exposing their arms and legs to the sun for 10 to 15 minutes twice a week in the summer, someone with the darkest skin might need two hours of exposure each time, Holick says. "It's impractical," he says, and it also darkens skin, which many people find cosmetically unacceptable. Dermatologists also warn that sun exposure increases the risk of skin cancer and wrinkling, even in dark-skinned people especially with Vitiligo. How much is enough? Holick endorses "sensible, limited sun exposure" but says it's also time to recommend that everyone, regardless of skin color, take a daily vitamin D supplement of at least 1,000 international units (IU). Not all scientists agree, but an expert panel at the non-profit Institute of Medicine is reviewing recommended daily intakes, now at 200 IU for people up to age 50, 400 IU for people ages 51 to 70 and 600 IU for those over age 70. An 8-ounce glass of fortified milk contains 100 IU. "All Americans, but particularly people with darker skin, should pay attention" to new guidelines due next year, says Adit Ginde, a researcher at the University of Colorado Denver School of Medicine. Ginde led a recent study, published in the Archives of Internal Medicine, that found that vitamin D levels are falling in all racial groups but are especially low in African Americans.