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Vitamin K2 aka The Grass Fed Vitamin

Updated: Jan 24

Vitamin K2 is a powerful anti-aging vitamin that is connected to reduced risk of Alzheimer’s, dementia, osteoporosis and heart disease as well as cavity free teeth and healthy skin with fewer wrinkles...

K2 used to be readily available in the average diet. This is no longer necessarily true.

When we talk about “Vitamin K” the distinction between vitamins K1 and K2 is commonly ignored but it’s important to understand that these are unique vitamins. They perform very different vital functions, and they are found in different foods. K1 is readily available, but certain modern food practises have all but eliminated K2 from many people’s diets.

The image below (from a google search) is an example of this common mistake:

Food sources of K1 and K2
To say "Vitamin K" is misleading. K1 is plant sourced, K2 is animal sourced.

Vitamin K1 – phylloquinone – is a key player in blood clotting. The human body doesn’t readily store K1 but because blood clotting is so essential, we have evolved to efficiently recycle it. Deficiency in K1 is quite obvious due to bleeding disorders but also quite rare because our requirements aren’t very high to begin with. Phyll means leaf in Greek and chlorophyll (green pigment in plants) is where you find phylloquinone.

Most plant foods provide some K1 and it is especially abundant in leafy green sources. It is also important to understand that K vitamins are fat soluble. This means they can only be found or transported in fat molecules. The cell membranes of plants are made of fat molecules and this is where we can find plant sourced K1. K2 is not found in the same sources as K1

Vitamin K2 – menaquinone – is an important cofactor in calcium metabolism. K2 helps gets calcium where it belongs in the body; in bones and teeth, and out of soft tissues and arteries. In a population lacking enough K2 we also see an epidemic of calcium related issues. Our bones are lacking enough calcium, and yet dangerous levels are also collecting in our arteries. K2 also has some unique antioxidant functions specifically in the brain and is considered to be an important anti-aging nutrient. In a deficient population we also see a rise in degenerative neurological disorders.

There are strong connections between vitamin K2 and reduced risk of Alzheimer’s, dementia, osteoporosis, heart disease and even cavity free teeth. In fact, K2 was first discovered by renowned Canadian dentist Weston A. Price when he observed that K2 nourished children consistently develop well-formed jaw bones, wide dental arches and straight teeth while the opposite could be observed in K2 deficient children.

Deficiency in K2 is fairly common and in many cases is quite invisible. We don’t see the onset of osteoporosis or atherosclerosis and often these chronic issues are only first diagnosed when they are already critical, like a broken bone or a heart attack. Just like K1 the body doesn’t readily store much K2, unlike K1 our body cannot recycle it. Gut microbes can make a small amount (if they are healthy) but otherwise K2 must be obtained from dietary sources.


Fruits and vegetables are not a source of Vitamin K2.

They will not provide enough K2 for optimal heart and bone health.


Just a sheep and a gander (Named Drake) who are in love...
Although Drake the gander and his girlfriend the sheep will never get eaten, they would technically be good sources of K2 because they have access to green food.

You can think about K2 as the grass-fed vitamin. When herbivore animals consume chlorophyll rich green foods, a significant amount of K1 is converted to K2 in direct proportion to the green food consumed. Humans can’t convert much. The speculation is, as we evolved as omnivores (higher on the food-chain) we didn’t need to convert because we had easy access to dietary sources of K2. For most of human history when we consumed green-fed meat, eggs and dairy we got ample K2 in the process.

When food production moved toward the modern industrialized grain fed model and the general population lost access to wild and pastured animal products, we also lost K2 before we really knew it existed.

The demonization of dietary fat in general has also contributed to our collective loss of K2. Low fat products are also low in fat-soluble vitamins. Years of substituting butter, cream, egg yolks and dark meat, for margarine, skim milk and lean protein has equated to years of missing out on fat-soluble vitamins.

We find K2 in the fat cells of animals that have had the opportunity to consume chlorophyll rich foods.

When we stopped eating the fat from green-fed animals we lost our dietary sources of K2. Nutrient supplementation can be helpful but remember that vitamins and minerals always interact with one another. and natural foods often contain complementary nutrients that work synergistically.

For example: Whole milk contains fat, protein, carbohydrates, digestive enzymes, minerals and fat-soluble vitamins A, D, E, K2. Fat and protein help to balance blood sugar, enables mineral absorption, contains fat-soluble vitamins. If the milk is raw/unpasteurized (illegal to sell in Canada) then it is a probiotic food and contains the digestive enzyme lactase, which enables digestion of milk sugars (lactose). Skim milk is missing natural fat-soluble vitamins, minerals are hard to absorb, mostly lactose (carbohydrate) so spikes blood sugar/insulin; pasteurized milk contains no enzymes to support digestion.

Vitamin K2 works best with other fat-soluble vitamins A & D and conveniently these are often found together in the same foods. Great sources of K2 include: egg yolks, full fat dairy, butter, liver paté, organ meats, bone broth, rendered fat, cod liver oil, etc. The reason that fish liver oil is also a good source is because of chlorophyl rich algae and sea vegetation within their food chain. Some microbes are excellent at making K2, so certain kinds of cheese, especially brie and gouda, have especially high levels. There is one extremely rich source of plant-based K2 called natto which is a kind of fermented soy – a vegan source!

Some great K2 sources include: egg yolks, full fat dairy, butter, liver paté, organ meats, bone broth, rendered fat, cod liver oil, etc (from animals that are able to consume some chlorophyll rich foods)

Where I live, on Vancouver Island, Canada, we are blessed with a long growing season and plenty of green space to raise farm animals. These factors likely contribute to generally higher K2 content in our local meat, eggs and dairy. One of the many benefits of buying local is you can ask your farmer about how their animals are treated and what they eat. On farms where green access for animals is made a priority, the K2 content will absolutely be superior. If anyone wanted another great reason to support local, ethical and sustainable farming practices, there you have it.


Vitamin K2 is an extremely complex topic that I have barely scratched the surface of here. Some say that K will go down in history as the most misunderstood vitamin ever and after probing the information available online I am inclined to agree this is true. There are lots of reputable sources presenting very incorrect and misleading information about K!


Vitamin K2 and the Calcium Paradox, By Kate Rhéaume Bleue, B.Sc., N.D. is an exceptional and in-depth book on the subject -

Effect of food composition on vitamin K absorption in human volunteers -

On the Trail of the Elusive X-Factor: A Sixty-Two-Year-Old Mystery Finally Solved -

Menaquinones, Bacteria, and Foods: Vitamin K2 in the Diet -

Vitamin K: food composition and dietary intakes -

Vitamin K status in human tissues: tissue-specific accumulation of phylloquinone and menaquinone-4 -

Why Grass-Fed Butter is good for you -

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