The study is provocative and "somewhat contrary to traditional thinking," said Dr. Adit Ginde, an assistant professor of surgery at the University of Colorado Denver School of Medicine. More work needs to be done to prove that vitamin D levels directly affect skin cancer development and to determine if increasing the levels will help people with melanoma, he said.
Vitamin D appears to be more than a cancer fighter. Low levels of vitamin D have been linked to a variety of health problems, including heart disease, infections and poor overall health. And adults with low levels may suffer from lower bone mineral density.
But researchers have noticed that vitamin D deficiency has been on the rise in recent decades. An earlier study led by Ginde found that more than 75 percent of Americans don't have high enough vitamin D levels, with African-Americans and Latinos at especially high risk.
Vitamin D is naturally present in few foods, and some researchers recommend supplements containing as many as 2,000 International Units (IU) of vitamin D for many people, and even more for those who are obese.
The current recommendations, however, are 200 to 600 units a day, depending on age.
The U.S. National Library of Medicine has more on vitamin D.
SOURCES: Julia A. Newton Bishop, M.D., professor, dermatology, University of Leeds, England; Adit Ginde, M.D., M.P.H., assistant professor, surgery, University of Colorado Denver School of Medicine; Sept. 14, 2009, Journal of Clinical Oncology
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