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Published on Monday, 08 April 2013 06:53

High vitamin K activity of menaquinone-7 In a study that was recently published as an advanced publication in the Journal of Thrombosis and Haemostasis (Theuwissen E, Teunissen K, Spronk H, Hamulyák K, Cate HT, Shearer M, Vermeer C, Schurgers L.J. Effect of low-dose supplements of menaquinone-7 [vitamin K2(35)] on the stability of oral anticoagulant treatment: dose-response relationship in helathy volunteers. Thromb Haemost. 2013 Mar 26. doi: 10.1111/jth.12203. Epub ahead of print), the efficacy of menaquinone-7 (MK-7, brand name MenaQ7) was tested in healthy volunteers the vitamin K status of whom was decreased by giving them a daily dose of vitamin K-antagonist (VKA). VKA treatment resulted in the production of undercarboxylated (i.e. inactive) forms of coagulation factors, osteocalcin and matrix Gla-protein (MGP). Subsequently the participants received increasing doses of MK-7 and it was monitored how the various proteins regained activity. Consistent with a similar previous study in which much higher doses were used (Schurgers, L.J., et al,.Blood 109 (2007) 3279-3283), we found that also at low daily intake MK-7 preferentially normalized the coagulation system, and that higher doses were required for also normalizing osteocalcin and MGP synthesis. It is concluded that patients using VKA as oral anticoagulant medicines should not take MK-7 supplements without consulting their hematologist. This is common practice for all other forms of vitamin K. A second conclusion is that MK-7 has a much higher potency than other forms of vitamin K that are commercially available. This holds true for proteins synthesized in the liver (clotting factors), bone (osteocalcin) and vessel wall (MGP). Therefore, MK-7 is the preferred form of vitamin K for those who want to optimize bone and vascular health. Unfortunately, this paper demonstrates that this option is not open for the limited group of patients using oral anticoagulant medication.