Calcium and vitamin D have long been the preferred micronutrient supplements grouped together to combat osteoporosis, despite the well-known roles that vitamin K plays in bone metabolism. The effectiveness of vitamin K supplementation to combat osteoporosis remains questionable due to conflicting results from various studies. The potential benefits of vitamin K supplementation to promote bone formation and reduce fracture risk are particularly important for postmenopausal women, as they constitute the largest group suffering from osteoporosis. Since vitamin K is often a minor topic in osteoporosis prevention, it is necessary to first examine how exactly it acts on bones at the molecular level. After focusing on vitamin K at the micro scale, research articles directly focusing on the potential positive effects of vitamin K supplementation in the postmenopausal target range will be analyzed. Following the discussion solely on vitamin K, the relationships between vitamin K and other nutrients involved in bone health will be called into question. Regardless of the controversies and debates surrounding vitamin K supplementation, it will prove beneficial in combating the onset of osteoporosis in postmenopausal women. Vitamin K is a fat-soluble vitamin that, at the time of its discovery, was thought only to influence blood clotting. Since then, our knowledge about the vitamin or group of vitamins has expanded significantly. We now know that vitamin K is an important cofactor in the activation of proteins belonging to the gla family (1. Vermeer C.). About 17 gla proteins have been discovered, including prothrombin, osteocalcin, and matrix gla protein. Pro...... middle of document ......on and research needs to be done to soften the edges, but the potential to stop osteoporosis is still there. It can often be difficult to know if a person is vitamin K deficient after menopause, especially since there are regulations regarding osteocalcin carboxylation. The low amount could be from diet, poor intestinal absorption, or perhaps even a need for a higher RDA for older populations. There are probably several reasons why osteoporosis occurs in a person, so eliminating any of the problems with an adequate amount of vitamin K will surely help. Two studies have shown the benefits of vitamins K1 and K2 as well as the usefulness of a vitamin K supplement in a group package so that it works to its maximum capacity. There is still a long way to go, but supplementation with vitamins K1 and K2 has the definite possibility of stopping the onset of osteoporosis in postmenopausal women...