Science / Study - 6
menatto® achieves more stable and higher blood levels of vitamin K than vitamin K1


Taking menatto® vitamin K2 (MK7) resulted in more stable and higher blood levels of vitamin K (7-8 fold higher) than vitamin K1. In addition, menatto® supported the carboxylation of osteocalcin, a protein that helps calcium bind to bone and thus keeps bones strong.*


Most vitamin K supplements are made from synthetic vitamin K1. menatto® is a natural form of vitamin K2 derived from natto, a traditional Japanese dish of fermented soybeans. In this study, researchers compared the effects of vitamin K1 with menatto® on various physiological parameters.

Study details

The study had 4 phases, to measure 1.) bioavailability, 2.) dose dependence, 3.) osteocalcin carboxylation, and 4.) interference with anti-coagulation medications. There were 10-18 participants in each phase, all men and women aged 25 to 35.

In the first phase, absorption and bioavailability were measured by taking blood samples at baseline, and again 2, 4, 6, 8, 24, 48, and 72 hours after a single dose of vitamin K1 or menatto®. In the second phase, dose dependence was tested with blood samples taken 4 and 24 hours after single doses of 50, 100, 150, 200, 250, 300, and 500 mcg of menatto®, with a 2-week washout period between each dose. In the third phase, participants took vitamin K1 or menatto® for 6 weeks, and researchers compared how the ratio of carboxylated (cOC) to uncarboxylated osteocalcin (ucOC) changed. In the final phase, participants were treated with an anticoagulant drug and then various doses of menatto®.


Both forms of vitamin K were absorbed well and reached peak concentrations about 4 hours after ingestion. However, menatto® had a much longer half-life than vitamin K1, which allowed it to achieve more stable and much higher blood levels (7 to 8-fold higher) after prolonged intake. menatto® also supported the carboxylation of osteocalcin more than K1.

Schurgers LJ, et al. Blood. 2007 Apr 15;109(8):3279-83.