Description: A new study of identical twins suggests that children who spend more time in the sun have a lower risk for developing multiple sclerosis (MS) as adults. "Evidence is building up that something in relation to sunlight and/or vitamin D exposure during childhood may play a protective role," said study co-author Dr. Thomas M. Mack, of the department of preventive medicine, Keck School of Medicine, University of Southern California, Los Angeles. "It's now been suggested by several different studies that this is the case, and if it's true, it would be important."