Vitamin K2: Bones Part 1: Clinical Trial from The Netherlands
It appears that I have exhausted the research on vitamin K2 and heart disease that measures direct outcomes in humans. I will summarize that research soon.
In the meantime, I have just finished reading a 2013 double-blinded, randomized, placebo-controlled trial on the MK-7 version of vitamin K2 conducted in The Netherlands (1).
The study included 244 healthy postmenopausal women who received either 180 µg of MK-7 or a placebo in one daily dose for 3 years. Bone measurements were taken after 1, 2, and 3 years.
There were so many measurements of bone health taken in the study at various parts of the skeleton that it would be tedious to read a list of each of them and what was found. Suffice it to say that there were some statistically significant reductions in bone deterioration in the treatment group that tended not to appear until the 3rd year. There was also a trend towards fewer moderate vertebral fractures in the treatment group, but the numbers were too small to determine statistical significance. To me, the trends seem too strong to be due simply to taking so many measurements that by chance some benefits were found from the treatment.
One caveat is that the trial was funded by Nattopharma, a company that makes an MK-7 supplement.
It should be noted that 180 µg of MK-7 is a much higher dose than you can get from animal products. In the Prospect-EPIC study, MK-7 intake from animal products ranged only from 0 – 2.2 µg (2). In contrast, the fermented soybean product, natto, has much higher amounts of MK-7 (about 775 µg per 100 g (3)).
1. Knapen MH, Drummen NE, Smit E, Vermeer C, Theuwissen E. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporos Int. 2013 Sep;24(9):2499-507. | link
2. Gast GC, de Roos NM, Sluijs I, Bots ML, Beulens JW, Geleijnse JM, Witteman JC, Grobbee DE, Peeters PH, van der Schouw YT. A high menaquinone intake reduces the incidence of coronary heart disease. Nutr Metab Cardiovasc Dis. 2009 Sep;19(7):504-10. | link
3. Abstract of: Tsukamoto Y, Ichise H, Kakuda H, Yamaguchi M. Intake of fermented soybean (natto) increases circulating vitamin K2 (menaquinone-7) and gamma-carboxylated osteocalcin concentration in normal individuals. J Bone Miner Metab. 2000;18(4):216-22. | link