The body requires an “alphabet soup” of vitamins, some of which get more attention than others. We all know vitamins A, C, and D, and lately vitamin B12 has become a household term. One vitamin that hasn’t received the attention it deserves is vitamin K2, also known as menaquinone (men-uh-QUINE-own).
Vitamin K1 is well known for its role in blood clotting, but the mainstream application of this knowledge is incomplete. Daily Recommended Values for vitamin K are based only on the known effects of vitamin K1, phylloquinone. Research suggests that vitamin K2 is even more important than K1 in the prevention of heart disease (Beulens et al., 2013).*
Vitamins K1 and K2 are both essential, but for different reasons. While K1 has an important role in blood clotting, K2 strengthens the bones and keeps the arteries from hardening. Research suggests also that vitamin K2 could be helpful in preventing or treating prostate cancer because it hampers the growth of certain kinds of prostate cancer cells (Samykutty et al., 2013).*
Where can we get this relatively obscure nutrient? Vitamin K2 is a product of microbes, so cheese and other fermented foods like natto (a Japanese fermented soybean product) are good sources. Other good sources are grass-fed meats, grass-fed butter, and pastured eggs, and also found in dietary supplements.
The jury is out on exactly how much vitamin K2 we need but I usually recommend 25 to 50 micrograms a day for healthy bones, heart, and prostate risk. *
Beulens, J. W., Booth, S. L., van den Heuvel, E. G., Stoecklin, E., Baka, A., & Vermeer, C. (2013). The role of menaquinones (vitamin K(2)) in human health. Br J Nutr, 110(8), 1357-1368. doi: 10.1017/s0007114513001013
Samykutty, A., Shetty, A. V., Dakshinamoorthy, G., Kalyanasundaram, R., Zheng, G., Chen, A., . . . Gnanasekar, M. (2013). Vitamin k2, a naturally occurring menaquinone, exerts therapeutic effects on both hormone-dependent and hormone-independent prostate cancer cells. Evid Based Complement Alternat Med, 2013, 287358. doi: 10.1155/2013/287358
* Statements on this website have not been evaluated by the Food and Drug Administration. The products offered here are not intended to diagnose, treat, cure, or prevent any disease.