Comparison of Efficacy of Different Dosages Vitamin K2

• The concentration of the circulating biochemical markers matrix-Gla protein and osteocalcin. Both proteins will be measured in their active form (carboxylated form) and their inactive form (undercarboxylated form). [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
  The main purpose of the study is to investigate the efficacy of different dosages bacterial vitamin K2 and vitamin K1 on carboxylation degree of the vitamin K-dependent proteins osteocalcin and matrix-gla protein.
  
  

• the number or type of bacteria in the stool [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]
  The second purpose of the study is to monitor whether the increased vitamin K intake will change the composition of the intestinal flora, as measured from the collected stools. Vitamin K, notably K2 is produced by a number of colonic bacteria and our principal is interested to learn whether the intake of extra vitamin K will affect the number or type of bacteria in the stool.
  
  

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).