Vitamin K is a group name for a number of compounds: K1 is present in chloroplasts in green vegetables, K2 is of microbial origin. Lactic bacteria produce a mixture of higher menaquinones, including menaquinone-7, menaquinone-8, and menaquinone-9. Higher menaquinones not only have very long half-life times (over 3 days rather than 1 hour for vitamin K1); K2 vitamins are also transported to extra hepatic tissues such as bone and vessel wall whereas K1 is preferentially transported to the liver. Nothing is known yet about the efficacy of bacterial K2 vitamins for in vivo K function (carboxylation of essential proteins). This study describes a dose-response experiment for different dosages of bacterial K2 which are compared with one selected dose of K1 and placebo. The efficacy is concluded from the carboxylation of the bone Gla-protein osteocalcin and of the vascular Gla-protein matrix-Gla protein (MGP).
Vitamin K is a group name for a number of compounds: K1 is present in chloroplasts in green vegetables, K2 is of microbial origin. Lactic bacteria produce a mixture of higher menaquinones, including menaquinone-7, menaquinone-8, and menaquinone-9. Nothing is known yet about the efficacy of bacterial K2 vitamins for in vivo K function (carboxylation of essential proteins). Therefore, this study was undertaken to study effects of different dosages of bacterial vitamin K2 on carboxylation of extrahepatic proteins.