Now Vitamin K-2 100mcg Capsules 100'sAlthough vitamin K is historically known for its role in normal blood clotting function, we now know that vitamin K is also essential to bone, cardiovascular, and nervous system health. As a biologically active form of vitamin K, K 2 is important for the formation of healthy, strong bone matrix. Vitamin Ks role in arterial health revolves around its ability to support proper calcium metabolism in vascular structures.