A new study by scientists at the U.S. Department of Energy's Brookhaven National Laboratory and colleagues in Norway suggests that the benefits of moderately increased exposure to sunlight - namely the production of vitamin D, which protects against the lethal effects of many forms of cancer and other diseases - may outweigh the risk of developing skin cancer in populations deficient in vitamin D. The study will be published online in the Proceedings of the National Academy of Sciences the week of January 7, 2008.