There are so many nutrients that contribute to bone health, but one that fascinates me is a form of Vitamin K2 called MK-7. This “super nutrient” is found in select foods and is a great compound to help improve bone health and — as more and more research shows — heart and arterial health.
MK-7 rivals bone drugs — without the toxicity
First, let’s talk about MK-7 for bone. A study last year (Zhu et al, 2017) found that MK-7 stimulates bone tissue and osteoblast precursors; so clear-cut are the effects that one Canadian researcher (Schwalfenburg 2017) noted that vitamin K2 “may be a useful adjunct for the treatment of osteoporosis, along with vitamin D and calcium, rivaling bisphosphonate therapy without toxicity.”
Notwithstanding my own perspective on whether bisphosphonate therapy is effective, this is a pretty extraordinary statement for a medical researcher to make!
MK-7 for healthy hearts and arteries
The benefits of MK-7 for reducing arterial hardening and cardiovascular disease are being explored by researchers at the same time. The results so far have been extremely encouraging.
As a recent three year clinical trial using 180 mcg of MK-7 reported, “long-term use of MK-7 supplements improves arterial stiffness in healthy postmenopausal women, especially in women having a high arterial stiffness” (Knapen et al., 2015). More recently, a 2017 study in kidney transplant patients — who commonly suffer from vitamin K2 deficiency — found that 8 weeks of MK-7 supplementation reduced arterial stiffness (Mansour et al. 2017).
As the Zhu study of MK-7’s effects on bones noted, MK-7 assists calcium in becoming mobilized out of the blood vessels and into the bone. Less calcium build up in blood vessels can mean less arterial stiffness. Vitamin K, it turns out, is crucial to as many as 17 different proteins that maintain bone and cardiovascular health (Wen et al., 2018).
Vitamin K2 requires a healthy microbiome to thrive
But there’s another interesting facet to this story. Another 2017 study (Ponziani et al., 2017) showed that people with small intestinal bacterial overgrowth had higher risk of arterial stiffness.
Here’s the thing: Vitamin K2 is produced by our intestinal bacteria, and a healthy microbiome will produce enough to support both bone and heart health. People with bacterial overgrowth, however, have altered vitamin K2 metabolism. That is, the body’s microbiome can’t produce what’s needed to maintain health if the gut is experiencing bacterial overgrowth.
Where to find vitamin K2
So let’s suppose you want to increase your vitamin K2 supply, and you’re not sure whether your microbiome is up to the task. Where do you look for a booster of K2?
One simple answer: Cheese.
Long-chain menaquinones like MK-7 are quite often found, in the Western diet, in true aged cheese, particularly hard cheeses like cheddar or Swiss, which are richer in menaquinones than soft cheeses. However, as one researcher notes, “the actual menaquinone content varies substantially and is dependent on the type of cheese, the time of ripening, the fat content and the geographic area where the cheeses are produced” (Vermeer et al., 2018).
With vitamin K status as a risk factor for cardiovascular disease and osteoporosis, for those who can handle dairy, cheese (and also yogurt) can prove a valuable adjunct to maintaining heart- and bone-supporting vitamin K2 status.
If dairy is not something you can tolerate, look at fermented vegetable foods like natto, sauerkraut, kimchee, and the like. Just as the bacteria in your gut produce vitamin K2, the bacteria in fermented foods do the same. Additional high quality, natural MK-7 is available as a high quality nutrient supplement.
Knapen MHJ, Braam LAJLM, Drummen NE, et al. Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women: double-blind randomised clinical trial. Thromb Haemost 2015; 113(05): 1135-1144.
Mansour AG, Hariri E, Daaboul Y, et al. Vitamin K2 supplementation and arterial stiffness among renal transplant recipients—a single-arm, single-center clinical trial. J Am Soc Hypertens 2017;11(9): 589-597.
Ponziani FR, Pompili M, Di Stasio E, et al. Subclinical atherosclerosis is linked to small intestinal bacterial overgrowth via vitamin K2-dependent mechanisms. World J Gastroenterol 2017;23(7):1241-1249.
Vermeer C, Raes J, van’t Hoofd C, Knapen MHJ, Xanthoulea S. Menaquinone content of cheese. Nutrients 2018;10: 446; doi:10.3390/nu10040446
Wen L, Chen J, Duan L, Li S. Vitamin K‑dependent proteins involved in bone and cardiovascular health (Review). Mol Med Rep 2018;1:3–15. DOI: 10.3892/mmr.2018.8940
Schwalfenburg GK. Vitamins K1 and K2: The emerging group of vitamins required for human health. J Nutr Metab 2017: 6254836. DOI: 10.1155/2017/6254836.
Zhu M, Ma J, Lu S, Zhu Y, Cui Y, Tan H, Wu J, Xu Y. Vitamin K2 analog menaquinone-7 shows osteoblastic bone formation activity in vitro. Biomedical Research 2017; 28 (3): 1364-1369.
I’m Dr. Susan Brown. I am a nutritionist, medical anthropologist, writer, and speaker. Get my free weekly newsletter here.