NOW Vitamin D-3 and K-2 veggie capsules combine two nutrients extensively researched for their contribution to the health of bones, teeth, and the cardiovascular system. Vitamin D-3 promotes calcium transport and absorption. Recent studies indicate that Vitamin D-3 may play a role in proper insulin action and glucose metabolism and has an important function within the immune system. Vitamin K is critical for the formation of a healthy, strong bone matrix. Vitamin K's role in arterial health revolves around its ability to support proper calcium metabolism in vascular structures. Vitamin K-2 is a readily active and biologically available form of Vitamin K. Natural color variation may occur in this product.