The Whole View, Episode 417: Vitamin K2, Hype, or Essential?

Welcome to episode 417 of The Whole View. In this week’s episode, Stacy and Sarah answer a listener’s question regarding vitamin K2 supplementation. What role does this nutrient play in the body? And can we meet our needs through diet alone? Find answers to these questions, and literally every vitamin K2 fact available, in episode 417 below! 

If you enjoy the show, please review it on iTunes!

The Whole View, Episode 417: Vitamin K2, Hype, or Essential?

Welcome back to the Whole View, episode 417, whereby Stacy and you get to be educated on K2. (0:27)

This is one of those, “I can’t say that I’m disappointed that we are talking about this” shows for Stacy.

Although she didn’t specifically ask the question, Stacy learned about K2 way back in the day and hasn’t learned much since.

Sarah is going to fix that today.

Before we jump in, we want to thank our returning sponsor Just Thrive.

Both Stacy and Sarah have used Just Thrive for years as their probiotic supplement, and swear by their product.

Stacy can’t encourage everyone to give it a try enough.

It is the only one that makes a difference that Stacy can actually feel.

Today Just Thrive is actually sponsoring with their K2-7 supplement.

If this is something you would like to try, you can get 15% off your order by entering in the code THEWHOLEVIEW when placing your order.

This code applies to anything on Just Thrive’s site.


Patreon Listener Comments

Before we dive into this week’s listener questions, we do have some fun comments to read in response to the first bonus audio content posted onto Patreon. (4:49)

For those who don’t know, this is a newly launched way that you can support us.

What we are doing to thank our Patreon family is posting bonus audio once a month, that is our behind the scene thoughts on each episode.

This audio is posted for our Patreon family only and is very uncensored.

It is uncensored from both the G-rated perspective, but also the level of unfiltered thoughts and viewpoints that Stacy and Sarah are sharing.

Kelby wrote, “First episode is 🔥! Love you ladies!”.

Jan wrote, I just finished listening to the content and I felt very reassured just to hear you all talking about your philosophy of nutrition.

It was a nice break from the science talk.

Don’t get me wrong, I love your scientific explanations, but it is often over my head and I struggle to wrap my brain around it!

It was nice to get a glimpse into your hearts and minds.

Thanks for being two of the lone voices of reason out there.

I’ve been so discouraged through this pandemic to hear many of my former functional medicine heroes give in to the conspiracy theories.

And I’ve seen even more of them fall down the dogmatic diet hole (particularly carnivore and keto).

So I feel a sense of calmness and much less anxiety when I listen to you two discuss life in an intelligent, rational manner.

THANK YOU for all you do, and stay strong!!”

If you haven’t yet checked out Patreon, you can do so here and check out the July content.

August content will be coming soon!


Listener Question

Mariel wrote, I’ve seen more brands starting to push vitamin K2 supplements as essential to take, especially if one is taking Vitamin D. (9:28)

I have a policy of avoiding supplements where possible unless they are whole food supplements or I have a medical reason for doing so, so I’m not sure what to make of company claims.

I’ve been scared into buying emu oil since I don’t think the Corganic liver capsules I take are going to give me enough daily K2 (and I don’t plan on eating 100 grams of liver or natto a day), but it’s pricey and I’m not sure if I’m wasting my money.

Help! Thanks!”

Stacy is feeling like Sarah is going to need to educate her on some of the details from that question.


Time & Place

Sarah shares a very similar philosophy to Mariel in the sense that she believes that first and foremost we should be attempting to meet our nutritional needs from diet. (10:21)

Supplements need to be taken with a reason.

We have this tendency to gives ourselves permission to not make the healthiest choices by relying on a multi-vitamin to fill in the gaps.

It is really important to not let a supplement be an excuse to not do the hard work of making healthy choices.

However, at the same time, even when we are making all of the healthy choices, there is a time and a place for supplements.

Sarah feels that supplements need to be taken intentionally and with a plan.

Mariel is right that there is some really important interplay between vitamin D and K2, and some growing science showing us that there is a compelling reason to take these supplements together.

First, refer to this podcast episode when looking for a deep dive into vitamin D.

We are going to start this with the assumption that everyone is on the same page.

That vitamin D is really important and that it is really important to get those levels tested.

We need to supplement accordingly from those results so that vitamin D can be in a functional range.


What is vitamin K?

So what does vitamin K do? (12:50)

Vitamin K is another fat-soluble vitamin.

The fat-soluble vitamins are A, D, E, and K.

The very first role of vitamin K that was discovered was in blood clot formation.

There are two main forms K1 and K2.

K1 is the dominant form that we get from food, which is the dominant form in vegetables and makes up most of what we are getting from our diet.

There are actually 13 different isoforms of K2. 

For example, Just Thrive K2 is actually MK-7, so there are 7 repeats of the 5-carbon units in the side chain.


Where do we get it from?

Compared to other fat-soluble vitamins, vitamin K is not stored very readily. (15:36)

Without regular dietary intake, vitamin K stores are rapidly depleted.

So it is more similar to a water-soluble vitamin in the sense that we need to be continually consuming it in order to have enough of it.

Vitamin K1 or phylloquinone is synthesized by plants and is the predominant form in the diet.

The K1 content of plants depends on how much chlorophyll is in their cells.

So leafy greens are the richest sources of vitamin K1: kale (472 micrograms/cup), Swiss chard (299 micrograms/cup), and spinach (145 micrograms/cup) are amazing examples.

The adequate intake level of K1 for men is 120 micrograms per day, and for women, it is 90 micrograms per day. 

So on the surface, it looks like vitamin K is very easy to get from diet.

However, there are two things happening here.

One is absorption, and the other is the adequate intake may be set way too low.

Sarah explained the difference between adequate intake levels and recommended daily values.

There is actually some evidence that we want a lot more vitamin K than this, and that K1 is very poorly absorbed into the body.

We are only actually absorbing 5 to 10% of the vitamin K1 we are consuming.

You can double the amount that you are absorbing if you also consume fats with your dark leafy greens.

What is very easily absorbed is K2, which we absorb about 100% of what we are eating.

K2 is synthesized by human intestinal microbiota and found in fermented foods and in animal products.

So while 90% of the vitamin K we consume is K1, about 50% of the vitamin K measurable in the body is vitamin K2.

This varies in different tissues; for example, human liver stores normally comprise about 90% menaquinones and 10% phylloquinone.

We don’t understand how the biological activity of the different forms of vitamin K differs.

What we do know is that all vitamin K can do the same job.

However, since we do see different forms of K2 in different tissues, it does imply that there is something important about that.

Right now in terms of scientific discovery, we don’t understand what that important thing is.


What does vitamin K do?

All of these different forms basically do the same thing. (22:20)

Vitamin K’s top-level function is that it is necessary for the activity of an enzyme called γ-glutamylcarboxylase (GGCX).

This enzyme catalyzes the carboxylation of the amino acid glutamic acid (Glu) to γ-carboxyglutamic acid (Gla). 

Remember that post-translational modification, like carboxylation, are essential for turning on or off many proteins.

Vitamin K-dependent γ-carboxylation that occurs only on specific glutamic acid residues in identified vitamin K-dependent proteins (VKDP) is critical for their ability to bind calcium.

So all of vitamin K’s roles in the body, which are really diverse, are basically related to calcium metabolism through really being able to activate different proteins that require binding to calcium in order to do the thing that they do.

Where this is applied in human biochemistry is in three main areas.

One is in blood clotting.

The other one is the regulation of a protein called Gas6.

Lastly, vitamin K basically controls where calcium goes into the body and stops it from going into the wrong places in the body.


Blood Clotting

In terms of blood clotting, vitamin K is really interesting here. (25:42)

The blood clotting is a really complex process that is performed in what is called the coagulation cascade.

This is a series of chemical reactions, where each step makes the next step possible.

Several of those steps require vitamin K.

So then with each of those steps, you are basically creating the proteins that make up the clot.

Vitamin K is needed to activate Clotting Factors II (prothrombin), VII, IX, and X, which make up the core of the coagulation cascade.

These proteins undergo a post-translational modification (vitamin K dependent ϒ carboxylation of glutamic acid residues) which enables them to bind calcium and participate in the clotting cascade.

Without vitamin K you couldn’t clot, and you couldn’t anchor that clot where it is supposed to be.

Vitamin K is also necessary for these other proteins that are anticoagulant.

We need vitamin K both to clot and to regulate clotting so we don’t clot all the time.



Vitamin K regulates a protein called growth arrest-specific gene 6 (Gas6). (32:57)

This protein is involved in many cellular functions, including phagocytosis, cell adhesion, cell proliferation, and protection against apoptosis.

Because of these functions, scientists think this is a key protein for the development and regulation of aging.

Through that, vitamin K has been associated as an important anti-aging vitamin.

Gas6 is found throughout the body; the nervous system is its main cellular home, but it is also in the heart, lungs, stomach, kidneys, and cartilage!

Defects or improper functioning of Gas6 has been linked to some serious health issues, including clot formation, atherosclerosis, chronic inflammation, and cancer growth.


Calcium Regulation

Vitamin D and vitamin K work together in a really important way with calcium regulation. (34:24)

This is really central to bone health, bone mineralization, and skeletal health.

Vitamin D both enhances the absorption of calcium from food and also controls the amount of calcium in the blood.

So if you are not getting enough calcium from your food, vitamin D will basically activate the cells that breakdown your bone in order to draw calcium from your bones.

Calcium does a bajillion things in the body.

We operate under a very controlled amount of calcium in our blood, and it is vitamin D’s job to control the amount of calcium that is there however it needs to.

The other thing that vitamin D does is promotes the production of a whole pile of proteins that need vitamin K in order to function.

This is where there is this really important synergistic action between vitamin D and vitamin K.

Where vitamin K really takes over in this calcium metabolism piece is vitamin D makes sure there is enough of it around in the blood, and vitamin K controls where it goes.

Sarah referred listeners to this vitamin D review article.


More on the Process

So it does this in a couple of different ways. (36:02)

Vitamin K activates osteocalcin a protein that promotes the accumulation of calcium in bones and teeth.

Osteocalcin (also known as bone Gla protein) is synthesized by osteoblasts (bone-forming cells).

Vitamin K activates matrix γ-carboxylated glutamate protein (MGP), which prevents calcium from accumulating in soft tissues such as kidneys (kidney stones) and blood vessels (calcification, or hardening, and atherosclerosis/plaques which eventually cause stroke, myocardial infarction, DVT, pulmonary embolism, etc.).

Vitamin K-dependent γ-carboxylation is essential to for several other bone-related proteins, including anticoagulation factor protein S, matrix γ-carboxylated glutamate (Gla) protein (MGP), Gla-rich protein (GRP), and periostin (originally called osteoblast-specific factor-2).

Sarah explained the way some studies highlight why you don’t want to have high vitamin D and low vitamin K.

There have been a bunch of studies in humans where they have done things like given vitamin D and vitamin K together, and they have shown that together they help to regulate blood pressure, improve the elasticity of arteries, and they have also shown that high vitamin D in the absence of vitamin K can drive this calcification.

This is an impact of what is called vitamin D toxicity, which can possibly be mitigated by increasing vitamin K.


Other Ways Vitamin D & K Work Together

While this is just emerging evidence where more science is needed, but it looks like these two vitamins may work together to help regulate glucose metabolism. (41:04)

There is some science showing that they may improve insulin sensitivity through a variety of different actions together where they are impacting the pancreatic beta-cell function.

Also, there is some emerging evidence that they are working together as immune regulators in some ways.

We know that both vitamin D and vitamin K interact with the immune system, and it appears that their joint action is an overall antiinflammatory reduced oxidative stress action.

Again, more science is needed on this.


Insufficiency Prevalence

So that is everything vitamin K does, so you kind of go – wow! (41:52) 

If you think about it as simplistically as helping to turn on proteins that are really important for regulating what calcium is doing in the body, then you understand how important this nutrient is for all the things.

When you look at the adequate intake level, it looks like it is really easy to get enough vitamin K.

However, it turns out that because vitamin K1 is not as easily absorbed, and there may be situations where our need for vitamin K is much higher than that adequate level, that vitamin K insufficiency prevalence might be high.

What is interesting though, is that this has actually not been well studied.

In normal healthy adults, 8-31% have vitamin K deficiency.

However, especially in older adults, more data is needed.

Sarah shared examples of why more research is needed on this and how our lack of information doesn’t provide a clear picture.

Two studies that Sarah referenced can be found here and here.

We are at this point where we are still learning about functional vitamin K insufficiency and what the implications are and how this relates to cardiovascular disease.

But what is really interesting is that the other area where vitamin K levels are monitored is in newborns.

There have been studies that have looked at vitamin K deficiency in newborns.

At this point, there doesn’t appear to be racial disparities in vitamin K levels, but that has only been tested in newborns because it is a new thing to look at in a functional way in adults.

Sarah’s guess as to what is causing our deficiency has to do with our intake of traditional foods, such as fermented foods and organ meats.

The average American diet is a terrible diet for the gut microbiome.

It is full of refined carbohydrates, there isn’t enough fiber, the fats are in the wrong amounts and are the wrong kind, and there are not enough phytochemicals.

Our gut microbiome is also extremely sensitive to the nutrient density of our diet.

So if we are eating a nutrient-deficient diet typically the gut microbiome suffers.

It is the sum total of all of the ways that the modern food system has hurt us is being reflected in vitamin K status.


Deficiency vs. Insufficiency

Stacy shared how this information really hones in the message repeatedly to her to be thinking as much as we can how to continue to inject that nutrient deficiency and put a nutrivore mindset into action.

It is not in a vacuum – it is not about one thing, and we see an example of this with vitamin D.

If that is the only thing you are doing, we see examples of how this can have repercussions on other things.

Sarah thinks it also highlights how hard it is to really meet the body’s nutritional needs in our current environment.

It shows how much effort needs to go into a nutrivore’s mindset in order to truly meet all of our nutritional needs.

This is something where we are going to go back to our ‘vote with your dollar’, which is the response that we have because we don’t have another option.

It takes a grassroots movement in order to be able to show companies that there is really a demand for these nutrient-dense foods that can fill in this nutritional gap.

Stacy mentioned at the top of the show that she started taking K2 early on into quarantine and it was because she was on the Just Thrive site poking around.

She is loving learning about why this nutrient is important but also realizes that she needs to be testing her vitamin D levels regularly as well.

Most people don’t have overt symptoms of vitamin K deficiencies.

Deficiency means your levels are so low that you are showing symptoms.

However, vitamin K insufficiency is much more insidious because the problems with this are seen over a really long timescale.

It is not the kind of supplement where you can feel a change when you start taking it.

The main long-term issues that low levels of vitamin K are associated with are osteoporosis and cardiovascular disease.

These are a direct result of vitamin K’s roles in calcium.



There is a growing body of evidence basically saying that we want to optimize both vitamin D and vitamin K together.  (59:41)

However, there is not enough science showing how much vitamin K to take relative to vitamin D.

Studies have basically shown that if you are taking less than about 800 IUs per day of vitamin D, that that level does not require additional vitamin K.

Over 8oo IU per day, more scientists are basically saying that vitamin D should actually be packaged with vitamin K if you are taking more than that per day.

There is this call for more big studies to look at how the higher doses of vitamin D.

Vitamin D supplementation needs to be customized to your personal needs.

It is important to measure your vitamin D and if it is insufficient, supplement, and retest.

Make sure that you are taking enough to get your vitamin D high enough and not too much that your vitamin D is going too high.

With vitamin K it is really interesting though because there is no upper limit.

There is no actual evidence of a toxic level of vitamin K.

The higher vitamin D is, the more we need vitamin K to help basically work in concert with vitamin D to control calcium.

If we are taking a large amount of vitamin D in order to get our levels into the normal range, that is increasing our needs for vitamin K and what we don’t really know is how much vitamin K.

What we know is that the adequate intake level needs to be reevaluated.

However, we can say that there doesn’t seem to be any risks when taking large amounts of vitamin K.


Why is 7 the Magic Number?

So why do we want to take K2-7? (1:03:10)

It boils down to a couple of things.

We know that seven is the dominant form of K2 that is produced by our gut bacteria.

Data suggest that vitamin K2 (menaquinone, esp. MK-7) has advantages over vitamin K1 (phylloquinone).

MK-7 form is the best-absorbed form for dietary supplements.

And, it has a long half-life of MK-7 resulted in much more stable serum levels, and 7- to 8-fold accumulation higher levels compared to K1 during prolonged intake.

Among the several vitamin K homologs, only MK-7 (vitamin K2) can promote γ-carboxylation of extrahepatic VKDPs, OC, and the matrix Gla protein at a nutritional dose around RDI.

We know that MK-7 does all the important things that we want vitamin K2 to be able to do, and it has been the best-studied over three years of supplementation.

Studies have shown that supplementation with MK-7 does the things that you would hope taking a vitamin K supplement would do – like improve the elasticity of our arteries and improves bone mineral density.

This is why it is so cool that the Just Thrive K2 is the best-studied form of vitamin K that checks all of these boxes.

They package it with magnesium and zinc to help actually increase absorption.


Closing Thoughts

Stacy is excited to hear from Sarah that this is a supplement that she would see the benefits from over the long-term use of it.

Bone health in general is something that Stacy tries to prioritize.

If this supplement is something you would like to check out, please visit this site here.

Don’t forget to use the code THEWHOLEVIEW to get 15% off your order, which can be applied to any and all of their products.

This code is good for subscriptions as well!

Thank you to our sponsor Just Thrive, whom we use and love.

And thank you to our listeners for listening to Sarah’s deep dive into the science.

If you have follow up questions, please feel free to reach out via social media or contact forms on both of their individual sites.

Stacy and Sarah will also dive a little deeper into this subject on Patreon.

Thanks for listening and we will be back again next week! (1:09:48)

You Might Also Like