Sun exposure and taking vitamin D supplements are the only proven methods, he said. "We were designed to live in sunshine ... Every year we go through this five-month stress test." Because the study followed patients after their vitamin D levels were measured, it is more rigorous in design than other research that merely found a retrospective link between vitamin D levels and cardiovascular disease, said Denise Teves, an assistant professor of medicine at the Medical College of Wisconsin in Wauwatosa who was also not involved in the study. Full Article at RedOrbit