Vitamin K2: The Complete Guide

Could this fat soluble vitamin be the key to your long term health?

For nearly 100 years it’s been known that vitamin K is necessary for blood clotting. Now this nutrient is making waves for its other roles in supporting bone health, preventing dental decay, supporting cardiovascular health and many other new findings [*][*][*][*].

Specifically, the K2 form of Vitamin K is taking the spotlight in much of this research.

 

Let’s take a deeper look into vitamin K, specifically vitamin K2.

 

What is Vitamin K2?

Vitamin K is 1 of the 4 fat soluble vitamins - A, D, E and K. Fat soluble means these vitamins need fat to be absorbed and to be utilized in the body. Fat soluble vitamins are stored in fat tissues and are required for functions in the body involving fat.

Vitamin K is broken down into two different forms - K1 and K2. Vitamin K1 is the plant form of vitamin K called phylloquinone. Think of chlorophyll, the pigment that gives green leaves and vegetables their color. Vitamin K1 is mostly commonly found in green leafy vegetables like spinach, kale and collards.

Vitamin K2 is found in animal tissue, so it is the animal form of vitamin K and called menaquinone. There are several forms of menaquinone denoted by the length of their prenyl side chains. They are named MK-n, where M means menaquinone, K is for vitamin K and the n is is the number of the prenyl side chains. Examples are MK-4 , MK-7, MK-8 and MK-9.

Digging deep into science and the biochemical reactions of the body, vitamin K2 primary job is to work with compounds called GLA proteins (gamma-linolenic acid). GLA protein is involved in coagulation factors, thus vitamin K2’s role in blood clotting. There is also a GLA protein called osteocalcin that we’ll talk about more in depth later on, but know that you want it in your bones, not your arteries.

Another important GLA protein is 'matrix GLA protein'. It helps to prevent the calcification of the tissues you don’t want calcified (i.e. your arteries), while making sure that your bones and teeth do get calcified (stronger bones).

Also there is the GLA protein called "growth arrest specific protein 6' (GAS6) that is secreted when you’re injured to help with healing.

Vitamin K2 works with all of these different GLA proteins and helps them to function at full capacity.

 

The History of Vitamin K2

Vitamin K was discovered in 1929 as an essential component for blood clotting, which is known as coagulation. This initial research was done as a by-product of a study on fat in chicken feed. Yes, you read that right!

A Danish scientist was doing a study on fat, specifically cholesterol, in chicken feed by seeing what happened when you removed fat from their diet completely. The poor fat deprived chickens began to bleed out from their tag sites and other areas. He discovered not only is fat necessary for the chicken health, but vitamin K, which is fat soluble, is needed for blood coagulation.

Somehow the chicken fat study is credited for discovering vitamin K, but the vitamin had appeared in a German scientific journal a bit earlier asKoagulationsvitamin. This is how it came to be known simply as "vitamin K".

Fast forward to 1943 and the same Danish scientist who did the chicken feed fat study, Henrik Dam, and a scientist from Saint Louis University, Edward Adelbert Doisy, won the Nobel Peace Prize for the work they had done on vitamin K, including the discovery that there is both a vitamin K1 and a vitamin K2.

 

Vitamin K Daily Intake Recommendations

The current recommendations for vitamin K are set at "AI" levels - Adequate Intake. This is the absolute minimum to consume rather than the ideal amount. This "AI" type of recommendation is rolled out when there isn’t sufficient information scientific information to set a RDA - Recommended Dietary Allowance.

Typically this means a couple of things -- deficiency induced studies would be unethical because of severe health complications it would cause, or that science is still exploring this nutrient. Both of these prove true for vitamin K, whether it’s vitamin K1 or vitamin K2.

Aside from rare allergies to supplementation, no adverse effects have been reported from large supplemental doses of either vitamin K1 or vitamin K2[*][*].

Current Adequate Intake (AI) vitamin K recommendations for adults are:

It is thought these levels are woefully short of where they need to be. This is because when they were put into place scientists were exclusively looking at vitamin K’s role in blood coagulation by way of liver function.

Now it is known vitamin K plays an important role in many more functions including bone health and teeth health, as well as cardiovascular health.

All of this adds up to the current recommendations falling way short of where they need to be. What we now consider as being high doses may soon considered the norm.

Recent research on the MenaQ7® form of Vitamin K2 (the premier supplemental form) shows that dosages of 180mcg taken by women helped to reduce arterial stiffness [*].

Here's a link to our K2 supplements, we strictly use MenaQ7 in our products.

 

Signs and Symptoms of Vitamin K2 Deficiency

The first sign or symptom of vitamin K deficiency that probably comes to mind is not being able to coagulate your blood well and thus excessive bleeding. This is correct and will show up not only in cases of wounds, but also in the cases of nosebleeds, excessive menstrual bleeding, bleeding gums, blood in urine, and even blood in stool [*].

All of these are conditions to speak to your health care provider about because they could all be signs and symptoms of other conditions. If you experience these problems, please get it checked out by your healthcare professional right away.

Other signs and symptoms require a closer look as this is a nutrient needed for long term health. Over time, vitamin K2 deficiencies can lead to serious health conditions. 

 

3 Amazing Health Benefits of Vitamin K2

 

1. Vitamin K2 Helps Support Bone Health

Yes, vitamin K2 helps in blood clotting, and that’s because of its role in dictating where calcium goes. If it’s not needed for the series of calcium dependent reactions that clot your blood when you get a cut, then it needs to be in your bones creating strong bone mineral density. It’s vitamin K’s job to do that.

Vitamin K takes calcium from the bloodstream and with the help of another fat soluble vitamin, vitamin D, it packs the calcium into your bones by way of bone building protein called osteocalcin.

Having optimal levels of Vitamin K2 and D3 are crucial for maintaining your bone health.

Because of this and the mountain of evidence supporting vitamin K’s role in support bone health, the Ministry of Health in Japan has recommended vitamin K supplementation since 1995.

Stateside, vitamin K supplementation is just beginning to be considered for supporting bone health. Studies are underway to see if it’s effective in support normal bone growth. Specifically, the MK-7 form of K2 is showing great promise in studies [*].

 

2. Vitamin K2 Helps Support Cardiovascular Health

When someone is deficient in vitamin K, high concentrations of osteocalcin - the protein used to build strong bones - are found in arterial tissue and calcium gets packed into arteries instead of bones. This leads to calcification of the arterial walls.

Hardened arteries don't fair well with the constant pumping of the heart. Over time they rupture because they are unable to go with the flow.

What’s more is high levels of osteocalcin are found around the edges of arterial plaques. This is of great concern because arterial plaque buildup can lead to stoppage, a major health concern.

Eating vitamin K rich foods and supplementing with K2 have been found to lower the concentrations of osteocalcin in cardiovascular tissue and increase it in bone tissue - this helps to build strong bones and teeth instead of hardened arteries.

But what about the calcification that has already occurred in the arteries? Can vitamin K2 reverse arterial calcification?

Wow. That’s a great, but seriously loaded, question. Scientists do in fact get fired up about things and this is one of those topics. The studies that have been done on this have had serious flaws in them leading the results to be faulty at best.

For now the answer in theory is "positive", but scientists are still waiting on the results from properly conducted studies to come to a conclusive "yes".

In the meantime, there is no sense in letting improper calcification run rampant in your body or the body of your loved ones. The health benefits of vitamin K, especially when paired with vitamin D, are pronounced.

Eating vitamin K rich foods like leafy green vegetables and taking a quality vitamin K2 supplement paired with vitamin D are recommended ESPECIALLY if you already are experiencing weak bones and rigid arteries.

At Utzy we offer a K2 + D3 formula, click here to learn more.

3. Vitamin K2 Helps With Blood Clotting

Vitamin K’s original health benefit of blood clotting is still true and incredibly important. Unless you’re on blood thinning medications, you’re going to want to make sure you’re getting enough vitamin K in your diet.

If you’re experiencing any excessive bleeding and wanting the above mentioned health benefits you’re going to want to supplement with vitamin K as well.

For women who are dealing with excessive bleeding during menstruation you’re definitely going to want to eat vitamin K rich foods, take a probiotic supplement to help with the endogenous conversion of vitamin K1 to K2, and to take a vitamin K2 supplement.

 

Sources of Vitamin K2

Vitamin K1 (phylloquinone - plant form) is found in green vegetables, namely green leafy vegetables. Even green tea leaves have some vitamin K1. Dietary sources of vitamin K1 include asparagus, broccoli, Brussels sprouts, cabbage, collards, endive lettuce, green beans, green leaf lettuce, kale, mustard greens, parsley, peas, romaine lettuce, spinach, Swiss chard and turnip greens.

Remember that vitamin K1 is turned into vitamin K2 (menaquinone - animal form) by a health gut microflora. This requires both the consumption of vitamin K1 rich foods and a healthy gut bacteria to be present.

Vitamin K2 is made endogenously by animals, so it is found in animal products. It is also found in a couple of fermented foods like natto, a Japanese fermented soybean condiment. It’s also found in dairy products like the very distinct cheeses Swiss Emmental and Norwegian Jarlsberg.

Other dietary sources of vitamin K2 include organ meats and egg yolks.

 

Supplementing with Vitamin K2

Vitamin K2 is made endogenously (by the body) by converting vitamin K1 to K2. This process is done via good bacteria found in the body.

This conversion process takes place in the colon which means you’ve got to have a healthy colon, healthy bacteria in your colon, and be eating vitamin K rich foods on a regular basis.

High stress, poor diet, and antibiotics will kill off healthy bacteria in your gut. It’s a great idea for overall health to take a probiotic supplement, specifically one containing at least oneBifidobacteria and oneLactobacilli bacteria.

If you plan on getting your vitamin K intake solely from food, it is recommended that you look into taking a probiotic supplement.

Taking a vitamin K supplement is a great alternative, it makes it easy to get the vitamin K that your body needs.

If you plan on taking a vitamin K supplement, look for a vitamin K2 supplement specifically, not K1. Additionally, look for one that is in the MK-7 form, as it is showing great promise in bone, heart, and dental health.

Additionally, vitamin K needs vitamin D to do its work, so taking a K2 + D3 supplement is a great way to get all of your vitamin needs in one supplement.

K2 is often compared to nattokinase due to their simialr effects. You can read our breakdown of vitamin K2 vs nattokinase here. 

Vitamin K2 Safety Concerns

If you have a blood clotting disorder and/or are on any medication like Coumadin to prevent blood clots, vitamin K supplementation is not recommended for you.

Speak with your primary healthcare provider about dietary vitamin K intake specific to your health.

Vitamin K2 Infographic

In Closing

With so many benefits, it’s highly recommended to start consuming vitamin K rich foods on a regular basis and pick up a vitamin K2 supplement.

If you’re already in the care of a doctor for conditions related to weak bones or hardened arteries, speak with your healthcare provider about ways to incorporate more vitamin K2 into your holistic health care plan - diet, dietary supplements and possibly medication.

Sheila Amir is a health and nutrition writer in love with Durham, North Carolina and the Sheila of NutritionSheila.com. After spending several years as a nutritionist, she turned in her office keys for laptop life to research, write and present while on the go. When she puts the laptop down she's either on her yoga mat or out enjoying life in the Bull City.