Vitamin K is a cofactor required for post-translational gamma-carboxylation of vitamin K-dependent proteins, including coagulation and anti-coagulation factors; osteocalcin (OC), essential for bone metabolism; and matrix Gla proteins (MGP), an inhibitor of artery calcification. In addition to activation of OC, vitamin K2 induces collagen accumulation in the bone matrix. The principle effects of vitamin K on bone health are not to increase bone mineral density but to promote bone quality and bone strength. Vitamin K2, as menaquinone-7 (MK-7), is the only major vitamin K homolog which can activate OC at nutritional doses. The higher efficacy of MK-7 is due to its better bioavailability and longer half-life compared to other vitamin K homologs. Furthermore, a normal nutritional intake of MK-7 has been shown to activate MGP, which inhibit artery calcification, and has been associated with prevention of cardiovascular diseases. Thus, MK-7 is thought to contribute to calcium homeostasis in arteries as well as bones

In recent years, more people worldwide have suffered from diseases such as cancer, myocardial infarction, hypertension, osteoporosis, and diabetes mellitus. Diabetes mellitus and osteoporosis, well known as lifestyle-related diseases, have been considered serious problems in particular because full recovery is difficult. In 2007, the number of diabetes mellitus patients worldwide was reported to be approximately 200 million. Osteoporosis patients also amounted to approximately 200 million people worldwide. Against this background, many kinds of minerals have been used in the treatment and/or prevention of these lifestyle-related diseases. In particular, though the abundance of zinc in the body is very large, thus it is presumed to have a wide safety margin. Known as the second messenger, zinc has a wide variety of physiological functions, and attracts attention as an alternative to drug biological components. In this review, we outline the effect of zinc on the lifestyle-related diseases diabetes and osteoporosis.