The early 20th century was the Golden Age of vitamin research. Scientists identified previously unknown compounds and named them in order: vitamins A, B, C and so on. The B vitamins turned out to be a family: vitamin B1, vitamin B2, vitamin B3, for example, all the way through vitamin B12. A Danish scientist, Henrik Dam, identified a fat-soluble compound critical for blood clotting in 1929. The German journal that published his research termed the discovery Koagulationsvitamin, aka vitamin K. Most people are unaware that in addition to vitamin K1, which controls clotting, scientists are also studying vitamin K2 and vitamin K3. What does vitamin K2 do?
Will Vitamin K2 Do Anything for Your Health?
Q. I became interested in vitamin K2 about a year ago when my nurse practitioner told me to take it for my joints. Curious, I started researching it to see what it could do. And boy, what it can do! I take it every day now for general overall health and my joints.
I found two clinical trials on vitamin K2 with very encouraging results. Vitamin K2 supplementation increased bone density in older women in one trial (Osteoporosis International, July 2007). In another trial it reduced stiffness in women’s arteries (Thrombosis and Haemostasis, May 2015). Granted, women took supplements daily for three years to achieve these effects, but they are impressive results nonetheless.
What Does the Research Show?
A. Thank you for highlighting research on this compound. A review of the medical literature on vitamin K2 (menaquinone) suggests that it may play an important role in getting calcium into bones and keeping it out of arteries (Frontiers in Cardiovascular Medicine, Feb. 5, 2019). That could help explain both benefits you describe. Fermented foods such as cheeses or natto provide vitamin K2 in the diet.
Danish investigators are currently conducting a trial of menaquinone-7 supplements to see if they can alleviate aortic valve calcification (BMJ Open, Aug. 23, 2018). That would certainly be a significant health benefit. However, another recent study found that such supplements might actually increase calcification of blood vessels (American Journal of Clinical Nutrition, online Aug. 6, 2019). The researchers didn’t report any adverse effects, but it seems we still need more clinical trials to understand what this compound can and cannot do.