Of the 13 vitamins essential for human health, vitamin K is among the least familiar to most people. But that may change as researchers report new findings about the vitamin's key roles in the body, especially for bone health.
Like vitamin E, vitamin K is actually a group of structurally similar fat-soluble vitamins. It is necessary for the production of proteins needed for the coagulation of blood and other functions, and it works synergistically with vitamin D for bone health and possibly cardiovascular health. The K comes from Koagulation, German for coagulation, meaning the ability of blood to clot and thus prevent hemorrhage.