Recent advances in vitamin K-dependent Gla-containing proteins and vitamin K nutrition

Vitamin K is a multi-functional nutrient and various tissues modify their function in response to vitamin K bioavailability mainly through post-translational modification of vitamin K-dependent (VKD) proteins. In this review, we discuss five clinical topics of vitamin K nutrition and vitamin K-dependent Gla-containing proteins. Although the physiological roles of these VKD proteins need further elucidation, study of these proteins may open new avenues for therapy in the clinical field. The topics discussed in the review are focused on des-gamma-carboxyprothrombin (DCP) in relation to the pathogenesis of hepatocellular carcinoma, osteocalcin (OC) and undercarboxylated OC (ucOC) in relation to bone fractures and insulin sensitivity, matrix Gla protein (MGP) in relation to vascular calcification, and growth arrest-specific protein-6 (Gas6) in relation to inflammation and platelet aggregation. Finally, interaction among vitamins were discussed.