What You Should Know About Vitamin K2

know about vitamin k2

What Is Vitamin K2?

Also known as menaquinone, vitamin K2 contributes to the health of bones, arteries and blood vessels. It also helps with tissue renewal and cell growth. You may have also heard of Menaquinone 7, shortened to MK-7, a specific form of K2 readily found in certain foods. MK-7 is considered to be the best form of vitamin K2.

It’s important to understand that vitamin K2 is distinct from other forms of vitamin K. There are actually three different forms: K1, K2 and K3. Vitamin K1 is found in leafy green vegetables. K2 is produced by bacteria and found mainly in fermented foods and organ meat. Vitamin K3 is a synthetic product that is typically not found in dietary supplements.

Sometimes the different forms are discussed as one nutrient, simply “vitamin K”. You may have heard that vitamin K, generally speaking, helps with blood clotting. However, K2 has its own distinct merits, and is absorbed by the body more easily than is K1.

Calcium is an extremely important mineral. It is more than just building material for bones and teeth, as it plays a role in many biological functions. The main function of Vitamin K is modifying proteins to give them the ability to bind calcium. In this way, it “activates” the calcium-binding properties of proteins.

Here’s where the roles of Vitamin K1 and Vitamin K2 are quite different. Vitamin K1 is mostly used by the liver to activate calcium-binding proteins involved in blood clotting, while Vitamin K2 is used to activate proteins that regulate where calcium ends up in the body.

We want to signal calcium to go to the bones, not the arteries.  Notice that as the population ages, there is a tendency for bones to become softer and brittle, while arteries become hard.

Abnormal deposition of calcium occurs in the vascular system in three places: the inner lining of the arteries (the intima), where atherosclerotic plaque builds up; the muscle layer of the arteries (“medial calcification”); and heart valves. Vitamin K2 signals calcium to go to the bones and avoid the arteries and valves.

In the Rotterdam study, those who had the highest intake of Vitamin K2 were 52% less likely to develop calcification of the arteries, and had a 57% less chance of dying from heart disease over a 7-10 year period.



The University of Oregon’s Linus Pauling Institute reports that “There are few studies on associations between menaquinones and bone health, perhaps because of the limited number of dietary sources…in Western diets.” However, scientific information is out there.

For example, two studies of Japanese populations linked consumption of natto, a fermented soy product common in Japan, with improved bone health for men and postmenopausal women.

According to the Marshall Journal of Medicine, “Vitamin K is known to play an essential role in the coagulation cascade; however, a growing body of research has found that a subtype of this vitamin, vitamin K2 (menaquinone) may have a beneficial effect in osteoporosis, cardiovascular disease, and cancer.”

Additionally, a three-year study of 244 postmenopausal women shows that K2 can help decrease bone loss in mature women and instead encourage bone strength! The study ultimately concluded that “supplementation significantly decreased the age-related decline in bone mineral density and bone strength.”



The Pauling Institute also notes that certain people could be at increased risk of vitamin K (not just K2) deficiency. This is especially true for those with significant liver damage or disease; or those with fat malabsorption disorders, including inflammatory bowel disease (Crohn’s disease and ulcerative colitis) and cystic fibrosis.

Symptoms of vitamin K2 deficiency may include excessive bleeding and bruising, cartilage calcification, and vascular calcification (“hardening of the arteries”).


Where To Find It

K2 is produced by certain bacteria during the fermentation process. Examples of foods high in vitamin K2 include sauerkraut, chicken livers, certain yogurts or kefir, certain types of cheese, raw butter, miso and natto.

Unfortunately, fermented foods and animal livers don’t suit everyone’s taste; and the latter is definitely out for vegetarians.

Furthermore, not all fermented foods contain it. For example, most commercial yogurts contain negligible amounts, if any. According to the National Institutes of Health, diets in the U.S. are simply low in K2 compared with other cultures.


Other Ways To Obtain Important K2

You can ferment your own vegetables with a beneficial probiotic bacterial culture called bacillus subtilis natto. This helpful bacterium, designed to produce vitamin K2, is available from some natural health stores. (Only certain bacteria produce the vitamin.)

You might also look for Natto Powder, which can be added to foods such as yogurt, milk, or soup. I recommend this Natto Powder from Amazon.

If that sounds like too much work or too much time, you can do what most of my patients and I do….get your K2 from a pure, high-grade supplement source.

According to researchers at Oregon State University, women should get at least 90 μg/day and men should get around 120 μg/day. The National Institutes of Health adds, “These guidelines are termed adequate intakes (AI) because the Institute of Medicine concluded in 2001 that there were insufficient data available to generate a precise recommendation for vitamin K.”

You may find vitamin K2 grouped into one pill with other ingredients with related benefits. I For my patients, I recommend taking K2 with Vitamin D3. Together, vitamin K2 and D3 make a truly efficacious bone and cardiovascular supporting supplement.

I recommend Diamond Nutritionals’ Vitamin K2 with D3. This ultra-pure formula provides a great source of both vitamin K2 (in the best form of MK-7) and vitamin D3, which promote both bone health and cardiovascular health.

As both K2 and D3 are fat soluble vitamins, they should be taken with a meal for optimal absorption.

I always recommend taking a professional-grade vitamin and mineral formula as a “foundation” to which other products are added. For many years, I have recommended Foundation Vitamins as part of a well-balanced health plan.

Always consult with your physician for any additional questions. You can always feel free to schedule a telemedicine (phone) consultation with Dr. Maxwell to get health questions answered! You may reach us at 513-741-8653 or 513-741-4404 to schedule a call or visit with us at our Integrative Medical Center.

Photo credit: sierpniowka / bigstock.com


Please enter your comment!
Please enter your name here