Vitamin K's function is underappreciated by both MDs and patients. It regulates calcium metabolism and protects against osteoporosis, arteriosclerosis, aortic valve calcification and regulates clotting. Adequate levels of vitamin K move calcium out of soft tissues such as arteries and heart valves and into bones, where we need it. Even people on Coumadin need small amounts of vitamin K to protect against osteoporosis and heart attacks and strokes. Coumadin doubles the risk of artery and heart valve disease as well as osteoporosis within three years!