Tuesday, June 17, 2008

Vitamin K2, menatetrenone (MK-4)

Weston Price established the importance of the MK-4 isoform of vitamin K2 (hereafter, K2) with a series of interesting experiments. He showed in chickens that blood levels of calcium and phosphorus depended both on vitamin A and K2, and that the two had synergistic effects on mineral absorption. He also showed that chickens preferred eating butter that was rich in K2 over butter low in K2, even when the investigators couldn't distinguish between them. Young turkeys fed K2-containing butter oil along with cod liver oil (A and D) also grew at a much faster rate than turkeys fed cod liver oil alone.

He hypothesized that vitamin A, vitamin D and vitamin K2 were synergistic and essential for proper growth and subsequent health. He particularly felt that the combination was important for proper mineral absorption and metabolism. He used a combination of high-vitamin cod liver oil and high-vitamin butter oil to heal cavities, reduce oral bacteria counts, and cure numerous other afflictions in his patients. He also showed that the healthy non-industrial groups he studied had a much higher intake of these fat-soluble, animal-derived vitamins than more modern cultures.

Price found an inverse correlation between the levels of K2 in butter and mortality from cardiovascular disease and pneumonia in a number of different regions. A recent study examined the relationship between K2 (MK-4 through 10) consumption and heart attack risk in 4,600 Dutch men. They found a strong inverse association between K2 consumption and heart attack mortality risk. Men with the highest K2 consumption had a whopping 51% lower risk of heart attack mortality and a 26% lower risk of death from all causes compared to men eating the least K2! Their sources of K2 MK-4 were eggs, meats and dairy. They obtained MK-5 through MK-10 from fermented foods and fish. The investigators found no association with K1, the form found in plants.

Perigord, France is the world's capital of foie gras, or fatty goose liver. Good news for the bon vivants: foie gras turns out to be the richest known source of K2. Perigord also has the lowest rate of cardiovascular mortality in France, a country already noted for its low CVD mortality.

Rats fed warfarin, a drug that inhibits K2 recycling, develop arterial calcification. Feeding the rats K2 completely inhibits this effect. Mice lacking matrix Gla protein (MGP), a vitamin K-dependent protein that guards against arterial calcification, develop heavily calcified aortas and die prematurely. So the link between K2 and cardiovascular disease is a very strong one.

Mammals can synthesize K2 MK-4 from K1 to some degree, so dietary K1 and other forms of vitamin K may contribute to K2 MK-4 status

The synergism Weston Price observed between vitamins A, D and K2 now has a solid mechanism. In a nutshell, vitamins A and D signal the production of some very important proteins, and K2 is required to activate them once they are made. Many of these proteins are involved in mineral metabolism, thus the effects Price saw in his experiments and observations in non-industrialized cultures. For example, osteocalcin is a protein that organizes calcium and phosphorus deposition in the bones and teeth. It's produced by cells in response to vitamins A and D, but requires K2 to perform its function. This suggests that the effects of vitamin D on bone health could be amplified greatly if it were administered along with K2. By itself, K2 is already highly protective against fractures in the elderly. It works out perfectly, since K2 also protects against vitamin D toxicity.

I'm not going to go through all the other data on K2 in detail, but suffice it to say it's very very important. I believe that K2 is a 'missing link' that explains many of our modern ills, just as Weston Price wrote. Here are a few more tidbits to whet your appetite: K2 may affect glucose control and insulin release (1, 2). It's concentrated in the brain, serving an as yet unknown function.

Hunter-gatherers didn't have multivitamins, they had nutrient-dense food. As long as you eat a natural diet containing some vegetables and some animal products, and lay off the processed grains, sugar and vegetable oil, the micronutrients will take care of themselves.

Vitamin K2, MK-4 is only found in animal products. The best sources known are grass-fed butter from cows eating rapidly growing grass, and foie gras. K2 tends to associate with beta-carotene in butter, so the darker the color, the more K2 it contains (also, the better it tastes). Fish eggs, other grass-fed dairy, shellfish, insects and other organ meats are also good sources. Chris Masterjohn compiled a list of food sources in his excellent article on the Weston Price foundation website. I highly recommend reading it if you want more detail. K2 MK-7 is found abundantly in natto, a type of fermented soybean, and it may be partially converted to MK-4.

Finally, you can also buy K2 supplements. The best one is butter oil, the very same stuff Price used to treat his patients. I have used this one personally, and I noticed positive effects on my skin overnight. Thorne research makes a synthetic liquid K2 MK-4 supplement that is easy to dose drop-wise to get natural amounts of it. Other K2 MK-4 supplements are much more concentrated than what you could get from food so I recommend avoiding them. I am generally against supplements, but I've ordered the Thorne product for a little self-experimentation. I want to see if it has the same effect on my skin as the butter oil (update- it does).


.^ said...

Okay, you make a strong case, but ... what I really want to know is does Oprah endorse K2?

Lee said...

Have you seen Anchor butter
from New Zealand? They advertise it as being free range. In the UK, it is widely available and the same price as other butter. But then it tastes much the same as other butter. I don't know about its vitamin content.

Stephan Guyenet said...

Haha, Oprah looks like she could use some K2 herself.

Lee, I haven't seen Anchor butter, but it looks like it's 100% grass-fed form their site. It should be more orange in New Zealand's spring and early fall if it's the real thing.

Unknown said...

I wonder if many vegans have had health issues related to K2 deficiency? Anyway, it's good to have more data showing how practices good for animals (except perhaps foie gras ducks) are also good for our health.

Stephan Guyenet said...


I don't know about vegans and K2 deficiency, but it would certainly make sense. The synthetic K2 MK-4 supplement would probably be a very helpful addition to their diet.

Dr. B G said...

This is great! Don't forget the other fat soluble vit -- E and the mixed tocotrenols...

esp on a high fat diet -- need the E to quench the ROS after lipid peroxidation! Usually E is find in the same foods as ADK2!

Raw milk also has a heat labile Wulzen factor (stigasterol --sp?) which is now manufactured into 'plant sterols' for cholesterol reduction. interesting huh??!!

Keep up the strong work Stefan!


Stephan Guyenet said...


Interesting. Price didn't talk about E but you're right that it tends to be in the same foods as A, D and K2. I suppose that suggests a meaningful role for it too.

Vitamin E is mysterious to me. Supplementing with alpha-tocopherol seems to be bad, but the E in foods isn't. It it the mixture of tocopherols/tocotrienols or maybe just the total amount? If it's the type of E, what's the right balance between types?

I doubt anyone has a convincing answer to all those questions, so I'll just continue taking the amount of E that nature hands me.

Dr. B G said...

When E is synthetic it causes problems (not accept donor electons, free radicals?). Most synthetic vitamins and hormones are toxic in fact.

This is a really good K2 post. I was just reading your comment on Peter's thread:
'People at risk for developing vitamin K deficiency include those with chronic malnutrition (including those with alcohol dependency) or conditions that limit absorption of dietary vitamins such as biliary obstruction, celiac disease or sprue, ulcerative colitis, regional enteritis, cystic fibrosis, short bowel syndrome, or intestinal resection (particularly of the terminal ileum, where fat-soluble vitamins are absorbed). In addition, some drugs may reduce vitamin K levels by altering liver function or by killing intestinal flora (normal intestinal bacteria) that make vitamin K (for example, antibiotics, salicylates, anti-seizure medications, and some sulfa drugs).'

Just like cows have 3 stomachs (right? have to verify w/Peter) and ferment their own source of K2, I think our own intestinal gut flora do the same. However, if we consume wheat, this may change bile acids, pH, or something where perhaps may be have less K2 produced. Just likes broadspectrum antibiotics kill off the normal intestinal flora and subsequently reduce fermentation of K2, maybe wheat is just as toxic by affecting the gallbladder and dysregulated bile acid secretion? Triple hit for heart disease! Bile acids from the gallbladder allow absorption of fermentation products which bind FXR and LXR in the nucleus for potent changes in cholesterol and antiinflammatory effects. Like K2... (and vit A and E and D2 from 'shrooms)... And Butyrate (4-C fatty acid) from butter... and butyrate from bacterial fermentation... Did you know that Butyrate binds PPAR?

Butyrate probably activates PPAR in the brain (which I haven't verified but suspect that it does)and affect many potent changes such as reduced anxiety/depression, ADHD, bipolar, etc.

I love how you discuss topics here!
Thanks, G

Stephan Guyenet said...

Thanks G,

The K2 that our intestinal bacteria produce isn't MK-4 and it doesn't function in the same way as MK-4 does. Cows are good at synthesizing MK-4 but we're bad at it so we have to eat cow. Unfortunately the food sources we depended on so much for MK-4 as hunter-gatherers aren't eaten much anymore.

But you anticipated my next post with the intestinal absorption comment!

Yuneek said...

"A recent study examined the relationship between K2 (MK-4) consumption and heart attack risk in 4,600 Dutch men."

Stephan, specifying MK-4 is an oversimplification of the study:

"Concentrations of phylloquinone and menaquinone (MK-4 through MK-10) in a large series of Dutch foods were assessed at the laboratory of one of the authors...


Menaquinone was present in meats and eggs (MK-4 only), fish, sauerkraut, cheese, and other dairy produce (MK-5 through MK-10)..."


Now I'm not bringing this up to be critical but rather with the hope that it will energize your talents to research and enlighten us on the entire class of Menaquinones (not just MK-4) and what their specific values are in our health.

Yuneek said...

Sorry for the double post. Got an incorrect password message on the first one (oddly enough since it posted).

Stephan Guyenet said...


You're right, I should have looked at that one more carefully. I've edited the post a bit to reflect it. Thanks for pointing it out. I've deleted your second (duplicated) comment, hope that's all right.

Dr. B G said...

HHHhhhmmm...pate! Sounds like a great source of K2 (and A, E and D)... sounds I feel like Hannibal... where's the chianti and favabeans?

Your skin looks so great -- now we know the secret :)

Let us know how the butter oil works -- if it's easy to get at Whole Foods, I shall try it as well in scrambled eggs. Sounds delish!

btw K2 from natto apparently builds very strong bones and has improvements in coronary calcifications, according to Davis. It appears every nation/ethnicity has a form of fermentation food-product. For Taiwanese, there is something that just smells HORRID called 'stinky tofu.' I've been curious to wonder if its the Chinese source of K2 ? Or could it be found in fermented 1000 yr eggs? or fermented jarred tofu?(since you're right, our colon coliform don't form too much of this good stuff). The French have their hard cheeses, Greeks feta, etc. What about the Asians?? Stinky tofu tastes GREAT btw!


Stephan Guyenet said...


You must have a palate of steel. I tried stinky tofu once and I'm lucky to be here to tell the tale. My olfactory bulb almost exploded. I pride myself on enjoying various ethnic and fermented foods, but that stuff tastes like dumpster!

You're right about K2 MK-7 and the other bacterial menaquinones. They do seem to overlap in function with MK-4 somewhat, most notably in bone health. I bet they play some role in health, but I'm still not convinced they're a good replacement for MK-4. After all, Weston Price searched for but did not find a strict vegetarian culture with excellent health. This suggests to me that the menaquinones gotten from fermentation aren't the whole package.

I would be willing to believe that bacterial menaquinones have unique benefits, but I haven't seen any evidence to support that so far. Many of our organs seem to have a distinct preference for MK-4. It doesn't last very long in the bloodstream, presumably because our starved organs pump it up immediately. MK-7 has a longer serum half-life. This is a benefit according to its proponents, but I'm skeptical. MK-4 is the form mammals synthesize for their own use and for feeding to their youngsters by way of milk and eggs.

Sue said...

In your opinion is this an okay supplement:
"Each capsule of K2C contains Vitamin K2 Menatetrenone: 5 mg, Vitamin K2 Menaquinone-4 or 7: 1 mg and Vitamin C 900 mg so can be used for Vitamin K deficiency, ageing skin and cellulite."

Stephan Guyenet said...

Hi Sue,

Menatetrenone and menaquinone-4 are the same thing (MK-4), so that's a bit confusing. MK-4 has been used at doses of up to 45 mg with no notable side effects. You can get 1 mg of MK-7 from natto so that doesn't bother me.

My opinion on highly processed or synthetic supplements is that they are best avoided. Better to get the nutrients from good quality food.

While 45 mg MK-4 appears to be safe, it's probably more than you can get from food. It's also isolated from the other nutrients it would normally occur with. You're taking a risk anytime you put something in your body that's outside its normal operating parameters.

Stephan Guyenet said...

Sorry, replace "45 mg" with "5 mg" in that last paragraph.

Dr. B G said...


You're too funny! MR. Zimmern on Bizarre foods eats nearly ALL foods that he encounters. The stinky tofu in Taiwan stopped him in his tracks -- or should I say -- stopped his CHOPS. He nearly hurled on screen which is a nearly rare event to behold! I'm not surprised your reaction as well ;D

Sea urchin -- can't stand that stuff -- but I actually do have a nearly iron stomach like my Dad :)

You know our liver activates (and de-activates) many of the vitamins and chemicals we encounter from food/supplements. Perhaps many of the MKs metabolites have different and longer biological half-lives than the parent? Keep up the strong work!!


Stephan Guyenet said...

You have a stronger palate than I! Although I do like sea urchin.

There are some metabolites of MK-4 (and perhaps others) that could play a role in health. Some people have hypothesized that the high levels of MK-4 given in the osteoporosis trials could have acted in part through one or more metabolites. There's lots yet to uncover here I think.

For now I'll stick with what I know works: MK-4 from well-raised animal products!

Unknown said...

No wonder this butter tastes so wonderful!! Also, this may be a coincidence (not a big enough sample size yet to know for sure), but the days I've eaten that butter, I've felt notably better (morning sickness-wise) than days I haven't eaten it. Hmmm... thanks!!

Stephan Guyenet said...

Hi Cristi, thanks for stopping by! Keep me updated on the morning sickness, I'm very interested!

JBG said...

Stephan, you said, "Finally, you can also buy K2 supplements. The best one is butter oil, the very same stuff Price used to treat his patients. I have used this one personally, and I noticed positive effects on my skin overnight, not to mention the delicious flavor."

I'm curious what the effects were that you were able to notice so quickly. Also, what butter oil you use.

I'm about to go buy some Purity Farms Organic Ghee to try myself.

Stephan Guyenet said...

Hi John,

The butter oil I use is made by Green Pastures. Just to clarify, butter oil is not the same as ghee. Butter oil is a concentrated version of butter that's rich in fat-soluble vitamins. Ghee is great too though; I highly recommend it for sauteing.

I notice the texture of my skin changes depending on my intake of K2 MK-4. If I eat a lot of grass-fed butter, my skin is smoother in the morning. It looks almost like my pores shrink, like some level of inflammation has disappeared. If I take butter oil, the same thing happens. I've been experimenting with the Thorne MK-4 supplement, and it does it too. I can only conclude that MK-4 improves my skin texture.

JBG said...

Stephan, thanks for the cue about ghee not being the same thing as butter oil.

Following up, I seem to find that...

Butter oil is made by centrifuging cream until the fat separates out and then extracting the fat.

Ghee is made by careful heating of unsalted butter until the water has been driven off and the non-fat residues have separated to the point where they can be removed by skimming.

It would seem, then, that the results are the same except that butter oil has been subjected to considerable physical stress, and ghee has been subjected to controlled but prolonged heat. If it is true that the two products are closely similar, there are important practical consequences.

I'm quite ready to believe that there are healthful components of cream/butter that are harmed by heat (the "Wulzen factor", eg). But if the focus is K2, ghee should be about as effective as butter oil, since K2 is reputed to be heat stable.

And whereas butter oil costs about sixty bucks for eight ounces, high quality ghee (Purity Farms) is available at retail for about $10 for 13 ounces, nearly an order of magnitude lower price. (Purity Farms is certified organic, and they have assured me by email that their ghee is made strictly from grass-fed butter.)

Reading some online forums, some users say that the taste of butter oil makes them gag, whereas it seems everybody likes ghee. My own test with a scant teaspoon of ghee on a slice of whole wheat bread and microwaved for a few seconds was favorable, taste-wise.

But I am completely new with all this, Stephan. Your thoughts in response would be very welcome.

Stephan Guyenet said...

Hi John,

Butter oil is a form of butter that is highly concentrated in vitamins. Weston Price used to make it by slowly solidifying melted butter. The longer-chain sat fat solidifies, leaving a layer of unsaturated and short-chain sat fat plus concentrated vitamins at the top. The butter oil from green pastures is also made from grass-fed butter (although I'm not certain if they use the exact same process WP used- I do believe it's unheated though). So it's much more concentrated in vitamins than ghee.

I find butter oil delicious. If you like butter, you'll like butter oil. It has a really intense buttery flavor.

I use ghee for cooking, and butter oil as a nutrition supplement.

JBG said...

Thanks, Stephan!

So butter oil, unlike ghee, consists of only *part* of the fat in butter (and is liquid at room temp)?

What sort of dose of butter oil do you use or advise?

Thanks greatly for your counsel!

Stephan Guyenet said...


Yes, butter oil is only part of the original butter. It is liquid at room temperature.

I'm not sure about the recommended dosage of butter oil, but I think it's 1/2 or 1 tsp.

Glad I could help!

JBG said...

Well, I've been using the Purity Farms ghee for about a week and a half.* It seems to give my skin a slight oily patina. Does that sound similar to the effect you noticed with butter oil, Stephan?

I think the ghee has also made my fingernails stronger. I've decided to let them grow a while just to see how strong the effect is.

*Specifically, I carefully melt an ample teaspoonful of ghee in the microwave and pour it onto a piece of wholewheat bread from the co-op.

Stephan Guyenet said...

Hi John,

That sounds pretty similar to what I see. My skin gets smoother and a bit more shiny. It looks almost like my pores get smaller, that may reflect a loss of skin inflammation. I haven't noticed an effect on my nails, although I did notice that when I was on cod liver oil, as well as when I took hemp oil.

By the way, the one teaspoon dosage I recommended is for butter oil. You can eat larger amounts of ghee, and in fact, I'd recommend it!

JBG said...

I should have mentioned that for some time I've been following a diet and supplement regime designed, among other things, to maximize bone health. It includes ample vitamin A (from sweet potatoes, greens, etc) and ample vitamin D (from controlled sunning in summer and supplements in winter). Thus, the ghee/K2 is something added "at the margin", and the effect on my fingernails, if it holds up, is quite striking.

Stephan Guyenet said...

Hi John,

I hope your diet meets your goals. I'm interested to hear if the fingernail effect persists.

JBG said...

> I'm interested to hear if the fingernail effect persists.

OK, Stephan, here we are 18 days later, and the answer is: definitely! I lost (the tip of) one nail a couple days after my previous response in the usual way -- a small tear at the edge eventually catching on something. Also, a few shavings off the end of one thumbnail.

Beyond that, all are still growing, and strong as bone! Yesterday, I did a bunch of mechanical and home repair stuff, but, amazingly, no fingernail casualties.

Soon, though, I expect to declare the experiment a success and trim them. Long nails complicate many things, from typing to wiping the butt. I've begun punching holes in my sox...

Stephan Guyenet said...

Haha, OK well I guess it's time to declare the experiment over so you can stop destroying your socks. Thanks for the update!

Anna said...

Glad I came back to the K2-files. Quite an interesting discussion going on, folks.

I bought a jar of GP butter oil from a local dealer (home office nutritionist who is a member of the local Nourishing Traditions-WAPF chapter). Super expensive stuff and seemingly not available except by order or from a local dealer.

I love butter, but wasn't wild about the butter oil flavor. Yes, sort of gaggy if taken straight, but only slightly more than coconut oil. I don't eat toast or anything like it, but that sounds more palatable, than the straight spoonful I was taking. My son

Couldn't bear to toss the bottle when I hadn't used much of it 'cause of the cost, so for a while it was shuffled around in a fridge door compartment with condiments. Must check to see if it is still there (I didn't toss it, but I've had a cleaning lady who is ruthless in the fridge - my kombucha SCOBY, red wine vinegar "mother" & my homemade sauerkraut were early casualties right after I hired her, for instance, sigh). If I still have it, I wonder if it is still good from being chilled all this time? Hmmm. Don't really want to take chances with rancid oils, though, cost be damned.

Also reminds me I need to get back into the habit of using raw grass fed butter. I've got a couple pounds in the freezer. I keep it in the freezer for longer storage (plus the store is often out of stock for weeks at at time when I want to buy it). I take out a couple days' worth to store at room temp, but during the warmer months when butter left out melts into a mess, I forget all about the frozen raw mutter and just use stick organic butter (which is softer at fridge temp than raw butter).

But we eat a *lot* of the other foods that provide K1 & K2s, too.

I checked one local store this week, which only had cheap K1, somewhat more costly K2 (with no further explanation), and Jarrow Formulas MK-7 from non-GMO natto, 90mcg/60 softgels/2 mo supply for big bucks - $22+ (though cheaper than Mercola's MK-7, $39.95 for 30 days).

A quick online search seems to say that supplement sellers promote MK-7 (from natto) as prefereable to MK-4 (synthetic).

Stephan, thanks for this info on the Ks. I've known the WAP - Vit K connection for a while, but not in this great detail. I live how you deconstruct it for those of us who need the Cliff Notes. :-)

Stephan Guyenet said...

Hi Anna,

It should be pretty stable if you've kept it in the fridge. I'm amazed you don't like the flavor, to me it tastes great! But that was years ago; maybe they've changed something.

Butter oil is not exactly necessary for a healthy diet, it's just a convenient way for people to get important vitamins. It sounds like your diet is good so I wouldn't worry about it.

About the MK-4 vs MK-7 supplements, yes the people who sell MK-7 like to say it's better. Mostly because it has a longer plasma half-life. I find that argument totally unconvincing. As Chris Masterjohn has said, the shorter half-life of MK-4 may have to do with the fact that many tissues prefer it to MK-7 so they take it up more rapidly.

MK-4 is the form of K2 that mammals synthesize for their own use and their offspring. MK-7 isn't something that hunter-gatherers would necessarily have gotten much of. MK-7 may have its own benefits, but I think it's unlikely to be a replacement for MK-4.

I can't support any supplement that has more than 1 mg K2 in it. That's about the upper limit of what you can get from food. Any more than that and you're taking pharmacological doses and the long-term effects are unknown.

Anna said...

Sure enough, the butter oil jar was tucked undisturbed in the back of the fridge. It didn't have a rancid oil odor, either . I spread some on a grain-free coconut-nut snack bar (a recent experiment based on a WAPF recipe for healthy school lunch ideas), tasted it, and it was fine.

By the spoonful is ok, I guess, but as much as I like, no, love fat and butter, 100% fat such as butter oil or coconut oil is not as pleasant on it's own as when loaded on a "vehicle transport system". That's what I miss about bread and crackers - they're so darn handy for holding the good stuff.

I don't know if I'll buy another bottle of this super pricey butter oil (there only seems to be one brand and few sources from which to buy it), but I will make sure that this bottle gets used up.

Thanks for all the posts and comments, Stephan.

JBG said...

Stephan, back in July you mentioned that you had been experimenting with the Thorne MK-4 supplement. Have you come to any conclusions?

The Thorne data sheet for the vitamin k2 liquid product says each drop contains a mg of K2 and to take 15 drops 3 times a day. That seems like a lot!

FYI, here is reference to a product that puts D and K2 (menatetrenone) in the same pill:


Stephan Guyenet said...

Hi John,

I've been using the Thorne supplement for several months now. I take a dose of one drop a few times a week. I agree that their recommended dosage is enormous. The reason they suggest it is that's the dosage they used in some of the Japanese bone density trials.

I notice a similar effect on my skin from the Thorne supplement as I did from the butter oil. Therefore, I think it's probably the K2 in butter oil that's causing the effect.

I probably won't continue using it long-term because I prefer getting my nutrients from food rather than supplements. But I may continue to add small amounts to my ghee or cod liver oil.

That product you linked to looks pretty good. I like that it has both D and K2 MK-4 together, but in reasonable amounts.

Elizabeth G said...

Hi Stephan,
Wow. I appreciate the information you are providing about the K2. I am writing a book about indigenous knowledge with a focus mainly on Native Americans. The things they called a "blessing from the Creator" always had a nutritional benefit. Such as the liver of the buffalo, which was eaten raw at the kill site. Hmmm, Indian people had a purpose and an intent moreso than we realized.
Appreciate it!

Elizabeth G

Stephan Guyenet said...


I agree. They didn't know about vitamins and minerals but they knew which foods built and maintained strong bodies. Now we're in the opposite situation, where we know all about nutrients but nothing about which foods actually sustain health. I really do believe that non-industrial people like pre-contact native Americans had knowledge that, while less extensive than what we know now, was more practical and effective in some ways.

Dr. Neustadt said...

The only dose of MK4 shown to decrease fracture risk 45 mg/day. In fact, it's prescribed in Japan as an osteoporosis treatment. It can decrease fracture risk by up to 81%, according to the Archives of Internal Medicine, which is greater than all of the medications, without the risks. The only product that has 45 mg of MK4 is Osteo-K (www.nbihealth.com).

Stephan Guyenet said...


I'm not going to delete your comment even though it's an ad, because it sounds like you might have actually read the post. But I will point out that

a) non one has shown that 45 mg is the optimal dose

b) you can get 45 mg/day using the Thorne drops as well

James said...

Thanks again. As Yuneek discovered there was the Dutch study that I stumbled upon by accident. I am especially grateful because of the material presented here. My wife graduated from Wageningen with a degree in Nutrition, but ever since they opened a special "leerstoel" (area of studies) sponsored by the National Dairy Board we did not really have too much faith any longer in their scientific independence and objectivity in the area of anything dairy related. Agriculture is a big thing at Wageningen. The fact that it was a co-operation between four completely different intitutions lent it quite a bit more credibility.
However I am still reluctant to let the menaquinone content of cheese count too heavily. Cheese is not only sat.fat but high in protein too and since most cheese is from pasteurised milk, which wipes out the enzyme activity, I have strong reservations with regards to the casein (which hardly better than glue)
I won't heap any more praise on your shoulders;you might get light headed, but I enjoy it a lot and evenhas me revisit old haunts like the Nurses Study and Willett's more recent comments. Granted he has a tough job there and is going about it very tactfully.

Stephan Guyenet said...


You can buy raw milk cheese that retains its enzymes, and the fermentation process adds enzymes as well. Raw milk cheese has supported healthy cultures in the past, but I don't think it's necessary for health. No dairy is necessary for health, but I think pastured butter or ghee is a good addition to most peoples' diets for the fat-soluble vitamins.

Unknown said...

Some Indians were vegitarians. Did you really do your research??

This K2 thing is just like B-12. I didn't need to take B-12 and I don't need this. Where do the cows, chickens and pigs get it?

So animal products prevent tooth decay??? Why is tooth decay so big in the USA then???

Jason said...

Hi, Stephan.

Just recently found your blog and love all your posts regarding K2 (activator X).

I read the comments above about the perceived effect of K2 MK-4 on your and other's skin. I also saw that one other noted a noticeable difference in their nail growth.

I began supplementing with K2 MK-7 (source naturals) - not MK-4 - a few weeks ago and I can report that I have noticed the same effects that you and the other reported, especially the nail growth and much improved integrity. I can honestly say that my nails are growing the best they have, probably ever. The other individual noted that his nails were hard like bones, and mine are also very strong and sturdy now since supplementing with K2 MK-7.

So, my point is that I believe that this may substantiate the fact that MK-7 does produce beneficial effects that parallel that of MK-4; However, to what degree, I am uncertain, of course. But, it seems to be doing me good!

Just a general note, I also eat beef and veal liver frequently (plenty of good natural vitamin A and other nutrients) and also get plenty of DHA omega-3 and vitamin D3, calcium and many other minerals in my diet and light supplementation.

Hope this is of interest!
Best regards.

Stephan Guyenet said...


Thanks for your observations, I'll keep that in mind.

Stephan Guyenet said...


Are you talking about American Indians? That's a pretty tall claim, you're going to have to back that one up for me.

Chickens and pigs naturally get B12 from animal foods because they're omnivores. Ever seen a chicken in a field? What's one of their favorite foods? Worms. Insects. In livestock operations, they supplement B12 in the feed to mimic this. Both species eat insects and small animals in the wild.

Cows get it from bacteria in their huge fermentative guts. Humans don't have that so we have to eat B12. It takes a long time to develop B12 deficiency (because the liver hangs on to B12) but it's extremely dangerous when it occurs. If you're not going to eat animal foods, you would be wise to supplement.

Animal products don't inhibit tooth decay when you also eat white flour and sugar all the time, don't eat organs, and raise your feed animals unnaturally.

Jason said...


I just noticed that in one of your earlier replies/comments you noted that Price made no mention of Vitamin E in his works (06/18/08):

"Price didn't talk about E but you're right that it tends to be in the same foods as A, D and K2. I suppose that suggests a meaningful role for it too."

I don't believe this is accurate. I recall Price referring to Vitamin E on several instances. I remember that he made mention of the fact that it was involved with the pituitary gland and had an influence in growth factors (or something to that extent) in Nutrition and Physical Degeneration.

In the Index at the back of the book, references to Vitamin E can be found on pages 304-305 & 331, where he discussed the connection with pituitary deficiency. He also mentions sources of the vitamin on page 331.

Best regards.

Stephan Guyenet said...


Thanks for the correction. You are a true Weston Price scholar!

Nick said...

Hi Stephan,

You said in your August 8 comment above:

"I haven't noticed an effect on my nails, although I did notice that when I was on cod liver oil..."

I am curious if you are still on cod liver oil, or if you determined that there is a better source for vitamin A (maybe your diet)?

Thank you for pointing out the synergism of vitamin K2, D3 and A. I plan to add butter oil to my diet right away and had my first raw milk this morning (it hasn't killed me).

By the way, I read the reference you made to K2 and glucose control and insulin release. In this respect, I suspect I have benefited greatly from moving toward a more paleo-like diet during the past several months (including omitting all grains). I thought the changes would be much more gradual, but now I see they can occur in just weeks.

I learned I was prediabetic and found that I was having unacceptable blood sugar spikes. My fasting blood sugar has plummeted and my OGTT came back completely normal, though my insulin and glucagon levels were measured far below the reference levels given (which I am still trying to get a handle on).

Still in awe of your Blog!

Stephan Guyenet said...


Awesome, I love success stories! There really is something powerful about a paleo-type diet. Or maybe a better way of putting it is that there's something profoundly damaging about the modern diet.

I have a post brewing about K2 and the pancreas. Apparently in mice, a K2-dependent protein is required for beta-cell (the cells that secrete insulin) proliferation.

I am still taking cod liver oil fairly regularly. I don't think CLO is necessary at all, it's just a convenient source of A, D and omega-3. I also just learned it's a source of iodine. I don't take it on days I eat liver.

Lee said...


I have been looking at the German food database German food database, which is available in English.
It is interesting since it gives values for amounts of vitamin K in a wide range of animal products.

Here is my summary of the amounts. The amounts are cals in 100g, mcg K in 100g and mcg K2 in 2000 calories of the food. Hope it makes sense.

Food 100g   cal K2 K2 in 2000kcal
egg (raw)
 chicken   154 48 623
 duck   183 45 492
 goose   179 45 503
 yolk   348 147 845
cooked liver
 pork   123 61 992
 beef   147 81 1102
 chicken   147 87 1184
 veal   146 97 1329
 liver pate   299 49 328
 C'bert/brie   362 35 193
 cream 40%   373 40 214
 milk,boiled   65 4 123
 hard cheese   356 25 140
 proces'd cheese   327 30 183
 sour cream 10%   117 10 171
 Edam 45%   354 30 169
 butter   741 60 162
 Corned beef   141 20 284
 Salami   365 14 77
 pork belly   469 8 34
 beef rib   146 13 178
 Ox tail   221 15 136

Other fats, offal, seafood and most meats contain none.


Stephan Guyenet said...


Thank you for posting that resource. Do I understand correctly that the second number is the mg of K2 per 100g of food?

Lee said...

It is mcg of K2 per 100g of food. So 48 for chicken eggs.

Stephan Guyenet said...


Very interesting. It says butter contains 60 mcg per 100 g, which is 4 times as much as a different lab found. That corroborates Weston Price's finding that the K2 content of dairy is highly variable. He found that pastured dairy is much richer in K2 than grain-fed dairy, with differences up to 50-fold. That finding hasn't been confirmed more recently, and his assays weren't quantitative so we don't know exactly how much K2 was in the samples he analyzed. It would be really interesting if someone analyzed pastured dairy.

Thanks again for posting those numbers. I wish I spoke German!

Lee said...

Click on the United Kingdom flag and everything will be translated into English. As far as butter goes, British cows are pasture fed when possible and brought inside over winter. I would guess that German cows are the same.

Lee said...

My German is not too good either but fortunately clicking on the British flag translates everything into English.

As far as butter goes, I think European cows are generally pasture fed when possible and brought inside over winter. As I mentioned before, New Zealand Anchor butter is pasture fed year round. After doing some comparisons with European butter, I have concluded it is better - yellower and with a stronger flavour.

Anna said...

Seen the Anchor butter adverts? Here's one, but there are gobs more online.


Here's the co's website about health benefits of grassfed butter:


Fonterra, Anchor's parent company has a cute little "story of milk" feature which is actually fairly informative, though their other page has nonsense about fat, calories, and health.


I saw on one of the gmail ads that Tropical Traditions is selling Anchor Butter online, too.

Stephan Guyenet said...


I went to the database and it looks like the numbers they list are for total vitamin K rather than K2 specifically. Am I missing something?

Lee said...

That's correct. The figures are for total vitamin K. I assumed that this is not a problem since we know whether a food contains K1 or K2.

Stephan Guyenet said...


I believe part of the vitamin K will be K1 in most if not all of those foods.

Sascha said...

This is all most fascinating. I thought I'd try a supplement and bought the Carlson stuff since it's cheap and comes in capsules that you can open to create smaller, more natural doses. However, the crystalline menatetrenone the capsules contain doesn't seem to dissolve in oil, at least not in a reasonable time frame. That is an unpromising circumstance. Now I'm hunting for genuinely grass-fed butter, which is not all that easy to obtain...

Anna said...


As Stephan has mentioned, the Thorne Research K2 oils drops are useful for smaller individual doses. A bottle is pricy (about $50) but goes a l-o-n-g way (there are probably well over 600 drop doses per 30 ml bottle, based on the 11 ml/365 drop Carlson bottle of D3 . I bought two bottles of K2 online which qualified for a 10% discount and perhaps free shipping. The shelf life of an unopened bottle is a long time and the oil is MCT from coconut oil.

I find the Thorne K2 drops are easy for adding to smoothies, in my coffee, to homemade ice cream (the heavy cream I buy at Trader Joe's is possibly not grassfed), to scrambled eggs, etc. I also like to travel with the tiny bottle (1 oz), because our butter intake goes down quite a bit away from home and I doubt we are encountering much grassfed anything then.

Also, look for these grass-fed butter options in your stores or online - I know they probably aren't local but in this case I'd chose them if your other options weren't grassfed. Personally, I think grassfed butter is worth the extra expense compared to commodity butter, and I'd scrimp on something else if necessary to be able to buy it.

Anchor brand from NZ (I saw it at Whole Foods and online) -

Kerrygold Irish butter from Ireland (it doesn't say grassfed on the label, but the website indicates their cows are on pasture). Trader Joe's has the best price I've seen on this, the best price on any grassfed butter I've seen, $2.69 for an 8 oz block wrapped in foil. Costco sells the salted version only in a three pack (3 x 8oz) for about the same per pound price as TJs). Other warehouse clubs might sell it, too.

Organic Valley (a co-op of family farms) has Pasture Butter in the green foil wrappers (8 oz bar) that is produced May -September from cows on pasture. They must make a ton and freeze it, because I see it in the market for at least 3/4 of the year, if not longer. It tends to sell for about $4 per bar, I think.

I've also seen a tub of whipped grassfed butter (8 oz) that I think is branded Made by Nature (I have a photo, but the "by Nature" part is all I can see). It was probably about $4-5 per container.

If you are in CA, there is Organic Pastures raw cream butter, too, but they are no longer allowed to ship or sell outside the state of CA. About $9 per pound in 8 oz & 16 oz tubs. Sold online, at their LA outlet, and in various "natural food" stores in CA (WF, Wild Oats, etc.).

Yesterday at a local farmer's market I found Spring Hill Cheese brand farmstead artisan butter from jersey cows on pasture in Petaluma, Sonoma county, CA. REALLY yellow! Haven't opened the package yet to taste it though. $5 for a vacuum packed block that weighs 8-3/4 oz. (I see it on their website store www.springhillcheese.com for $5.99) The website says the cows are on pasture January to July and they grow and ferment their own forage for the rest of the time. In CA, there isn't much green grass for the other half of the year, so forage for the dry season makes sense.

Also, there is Purity Farms Organic Ghee (clarified butter) in 6 or 7 oz and 13 oz jars. I buy the 13 oz jar and store it in the cupboard for quite a while with no rancidity problem, though it's in the cooler case with other butters at the store. I've seen this butter at WF and similar stores and their website indicates the cows are fed grass. I like the wide mouth straight-sided jar great for reuse with sauerkraut storage, etc.

I've never been able to find butter that I can identify as grass-fed, therefore high in K2, at conventional supermarkets, unfortunately. But I rarely shop at those, so that's no hardship. But it must be tough for locations without a variety of store types and only conventional options. I think online is the way to go then, stocking up and freezing. Well-wrapped butter stores well in the freezer (must be wrapped to avoid absorbing odors and drying out).

Sascha said...

Thanks, Anna, for the options. I have in fact ordered the Thorne stuff and just picked up some Kerrygold butter from a gourmet food shop (though I had to drive 45 minutes to get there). I see Organic Valley products in stores now and again, but I have yet to find their pasture butter. Unfortunately I'm not in CA...

Unknown said...


I wasn't able to find any butter in my area so I bought a capsule product by AOR it states each capsule has 120 mcg of K2 MK-4. It states 1 capsule per day. I'm thinking I should be taking more than one. What do you think of the product and how much of it could I take safely. Also Canadians may like to know I contacted Green Pastures and they put me in touch with a Canadian distributor called ST. Francis Herb Farm. 1-613-756-6279.

kauaimu said...

I must say that I have greatly enjoyed reading this whole K2 blog. Thanks a lot Stephan! ;-))
Now, I hope this is not taken as an ad, but there's been a lot of mention of GP's butter oil. However, no one seems to know that you can buy directly from them online at much cheaper prices by almost half if you buy in quantities of 6 products/items or more. They even have a blend of fermented cod liver oil and butter oil that Price had reportedly used to treat his patients. I'm not going to post their URL, but it should be easy to google.
A word of honesty though, I have not personally bought from them yet. I live in Saudi Arabia, and my attempt to place an order this weekend failed. So, I can hardly wait till Monday to call them by phone to see if we can resolve this problem. Happy hunter-gathering, everyone! ;-)

AnnieB said...

Ok, I've been reading and reading and reading, and most of what I've seen touted is the K2 menaquinone-7 form. So why is everyone talking now about the K2 MK-4 form? This is confusing the heck out of me.

Do you use both, or just one? What I got from my reading was that it was the menaquinone-7 that was used in the research studies. and the form that is in the 45 mg prescriptions used in Japan. Or is everyone else lying?

And, sorry to be so blunt, but I gotta tell ya, if you guys can afford 50.00 and 60.00 a pop for this stuff in this economy you're a lot better off than I am right now.

Stephan Guyenet said...

Hi Annie,

The K2 MK-4 is about the cheapest supplement you can buy, per dose. One of those bottles will last you over a year easily, if you take a normal amount (500 micrograms or less a day).

I don't know what kind of rumors have been floating around the internet, but all the studies showing lowered fracture risk with K2 supplementation used MK-4, not MK-7. MK-7 has never been directly shown to reduce fracture risk in humans.

All that said, I don't really recommend K2 supplements anyway: getting it from food is better.

Anna said...


Early last year I bought two bottles of the Thorne Research MK-4, which put me over an order price threshold for a 10% discount and free shipping. Pricey up front, yes, but it has a lonnnngggg shelf life and our family of three is still only at the halfway point in the first bottle. I think the per dose cost is quite reasonable for a very important nutrient that is probably not abundant in supermarket foods. I don't use it every day, nor do I have a regular dosing schedule, but I put a drop in our food here and there, especially if we aren't consuming as much grassfed butter as usual (such as when I'm on a coconut oil and coconut milk kick). I pack the little MK-4 bottle when we travel because I know our butter consumption drops a lot and it's unlikely what butter we do consume is from grassfed herds. We each get at least a couple drops a week when we are away from home.

Unknown said...

I'm from South Korea and my wife is on MK-4 45mg-a-day therapy. it does wonder to her bone and skin. But I need to mention that MK-4 therapy is generally not a good idea for men since MK-4 does contribute to coagulation factor and for this reason, MK-4 45mg-a-day therapy is not approved for men. It significantly raises ischemic stroke episodes for men.

Couves said...

Thank you for all the info on Vitamin K. My doctor found that vitamin D deficiency was largely to blame for some mysterious chronic pain that I’ve experienced. However, correcting that deficiency has not completely alleviated the symptoms. I haven’t had any luck with pasture butter, but it sounds like a K2 supplement is worth a shot. I’ll be sure to get one that has both MK-7 and MK-4.

Lisa said...

I just found your info on K2. Amazing. I thought I understood nutrition. Do you know of anybody who has been able to reverse arteriosclerotic damage to arteries once it has begun? Or refer me to someone? I ask because I tried to be vegetarian because I thought that would help prevent heart disease. Now my health has suffered. My LDL high and I have started getting heart pains. I suspect some long term nutritional deficiencies. Thanks for any more info you can sent me to. Lisa

Unknown said...

I have -2.8 t score on the dexa in my neck. I was wondering where to get 45 mg of MK-4 without mega doses of calcium mixed in? I had a very poor reaction to bisphosphonates and am looking for something else. Thanks!

Dr. Neustadt said...

Hi Stephanie. I'm not sure what you mean by megadoses of calcium, but Osteo-K (www.nbihealth.com) has the 45 mg MK4, with 1000 mg calcium (citrate) and 2000 IU vitamin D3.

Puddleg said...

Pharmacologic doses of vit K have unknown long term side effects? you mean, such as - reversing liver tumour - preventing liver cancer in persons with cirrhosis - these are the only side effects of 45mg K2 listed so far. They sound like side effects I can live with.
I don't buy into this "toxicity of synthetic vitamins" theory. As long as it exists in nature in that form (not l-tocopherol, for example) and other deficiencies are avoided it's OK with me. Some of the world's oldest and most active citizens are long-term takers of vitamin megadoses; if these were toxic, in any meaningful sense of that word, this could hardly be the case.

Unknown said...

To me, using Dr Weston Price's advice of getting mk-4 from the natural source 'fast growing grass fed butter oil' seems ideal, esp mixed with high vit cod liver oil for a good A,D,K mix.

Problem is, the recommended serving of a brand like Green Pasture, Blue Ice butter oil is just 2.5ml. I can't find any information on how much mk-4 would be in this small amount of oil. Does anyone have any idea please?

Dr Price documented using one off doses up to 20ml, but to use this product at that level on a daily basis would cost around $40 every 10 days! :(

Gerald said...

I like the idea of strengthening teeth and even removing cavities by Vitamin K2 intake. I have already bought some Green Pasture products, in this case the fermented butter oil and cod liver oil blend. However, I still lack knowledge of the necessary doses and types of exact treatment, be it K2 MK4, K2 MK7 and other vitamins like any types of vitamin d blends.

As a consequence, I would like to know the following:
What does science or research say about the doses necessary to remove caries cavities, and what kind of doses of what kind of vitamin would be necessary to perform this feat? And how long would it take to do that?

As far as the required doses are concerned, is it, for example, some amount of MK 4 only, or some dose of vitamin mk 4 combined with vitamin d, or is it MK 7... and how much and for how long would we need it... ?

So far I have not found sufficient information to answer this question anywhere else in the net, so maybe someone in this forum might be able to answer. Thanks!

Unknown said...

Hi Stephan,

How much K2 are you taking daily, and in what form do you currently use (butter oil or the drops?).


Unknown said...

Great conversation, thanks for all the info on the benefits of K2 and grass-fed dairy.

If you are not sure how much grass a dairy producers' cows are eating, ask them. "Pastured" does not equal 100% grass-fed, a label showing a cow eating grass does not equal 100% grass-fed (or ANY grass for that matter) and a video on a website showing cows grazing does not mean they eat a 100% grass-fed diet. Health benefits from grass-fed dairy drop off quickly as soon as cows are moved off 100% grass, and many "pastured" cows eat 30% - 70% grain as a supplement to increase milk production.

PastureLand Cooperative in Minnesota offers some of the only 100% grass-fed butter and cheese in the US. Our products are available in stores in the Midwest, and online at http://www.pastureland.coop/buy/direct

Thanks for letting us participate in the discussion!

Mark said...

Hey Stephan,
I don't know if you still monitor this but I have a quick question. I have been using Kerry Gold butter to get the vitamin-K benefits but I'm just not sure how much is needed to get the benefits? For supplements I take cod liver oil, iodine, vit-D3, magnesium and zinc. I'm trying to lose some fat so I'm counting calories and therefore it's hard to use a lot of butter but 1-2 tbsp would be easy to fit in. Any insight would be great. Thanks for your great site, much appreciated. -Mark

Mark said...

Subscribing to comments. Thanks again.

Jack said...

I was taking the Oslo Orange FCLO and the original flavor Butter Oil for a while. I don't know if it was just my bottle or if others feel the same way, but that 'orange' flavored CLO tasted absolutely putrid. I HATED it. I would squeeze some lemon juice into the spoon first and that would help a lot, but I still wanted to puke every time. The butter oil was delicious. But now I just take the cinnamon tingle gel blend of both and I'm so happy to say that it's very pleasent. It seriuosly tastes like cinnamon gummy bears. Odd though, that I have seen no positive effect on my skin as Stephan has. Maybe I wasn't taking enough.

Anyway I made homemade ghee for the first time the other night. Sooooooo cool.

For those of you not familiar with ghee, it is essentially clarified butter (milk solids 'lactose' and 'casein' removed). The end result is a golden yellow oil that is extremely high heat stable (excellent for cooking and even frying). I was going to purchase a batch from Pure Indian Foods, but instead decided to just venture out and make my own. It was SUPER easy and a total success on the first try.

Here's a link with some good pics. I chose method #1, which is to skim off the milk solids as you go.

Here's the site with pics I used for reference

All I did was:
-melted six 4 oz sticks of pasture butter in a sauce pen on med-low heat
-skimmed off and removed the gathering milk solids from the top of the melted butter with a spoon (as it was simmering)
-let it cool a bit
-strained with cheesecloth over a strainer into a bowl
-transferred from bowl into jar with a seal tight lid

Bam! perfectly yellow crystal clear grass fed ghee. It is delicious.

It's a huge savings to spend the 20 minutes to make it yourself. So excited about this :)

paymanz said...

its good information on that germany site but its very diferent than other sites like nutritiondata.com.im confused.what you think?

Unknown said...

Good blog, discussion and gathering of intelligent people helping and sharing. Kudos!

I grew up on ghee, as do most South Indians (from the Indian subcontinent). The flavor is delicious on almost anything. The Indian religious/mythological literature is filled with mentionings of ghee. Infants and children are especially fed ghee and its preparations. Would not be a stretch to say that Ghee is almost worshipped. Probably because of its wonderful vitamin ensemble.

Now the part about the "modern" findings that ghee is full of saturated fat not good for one's heart, and the high cholesterol (which reportedly has not been conclusively linked to heart disease but the bad association persists).

Anyway, since 20 years ago, I almost stopped eating ghee, and do in small qty. while acutely aware of this association, though I am healthy.

So, does anyone here have any clear information on ghee's sat.fat/heart health/cholesterol or info debunking/supporting this long standing "cardiac" industry's claims?

I will appreciate your input. Thanks.

Puddleg said...

To debunk the sat-fat, cholesterol myth, read Gary Taubes " good calories/bad calories" or Jeff Volek's research work. A diet high in sat fat but low in carbs will lower high cholesterol and elevate HDL more effectively than a low-fat diet.
There is a small link between high cholesterol and heart disease, but a similar link between low cholesterol and cancer. Which would you rather have?

it's not the ghee, its the sugar and flour and fruit juice and potato products that push up blood lipids.

The Galatian Free Press said...

Any thoughts about EDTA as a means to decalcify the blood and reduce plaques?

How does it compare to K2?

Char said...

Brand new to this site. Great information. I've been using certified organic expreller pressed coconut oli for my skin and for cooking. What is your opinion Stephan. I take many of the supplements mentioned and plan on buying Thorne's liquid MK-4 for my -3.4 dexa scan results. Also very interested in the Butter oil. Thanks for all the great posts. Char

pet said...

Two Q's: 1) Does high doses of k2 mk4 cause constipation? I take 5 mg/day and have been experiencing this. 2) Does mk4 help heal gingivitis? I had been taking 120 mcg of mk7 (natto) and had no constipation or improvement in my gums...still had lots of dental plaque too at my last cleaning.

radekisner34 said...

Haven't heard about such deficiency but if their some deficiency like that so thanks for giving advise what to do.

jewiuqas said...


I have a serious doubt; maybe there is someone out there who can provide some useful information. So, I have decided to do something about my vitamin K2 intake, as part of my program to prevent, stop, reverse tooth decay. In-stead of taking supplements, I intend to get my dose from the richest known natural source of K2 (MK4): foie gras. The problem is that foie gras is a common term for fatty goose liver and fatty duck liver. Some sources specify that the rich source of K2 is fatty goose liver, without any reference to duck liver. I wonder, if they simply overlooked the existence of these two kinds of foie gras, or they really meant only goose liver. The reason why I am inquiring into this detail is that in France, where I happen to live, fatty duck liver is much more readily available than the goose variety is. In addition, what is not a negligible circumstance either, it is much cheaper (it is not that very cheap though). I couldn’t find any information as to this on the Net, most sources citing only foie gras, or goose liver. The two species being so closely related to each other, and the way of breeding them to produce fatty liver being largely identical, I would find it reasonable that their livers be similar in nutritional values, composition. I would be grateful to anyone who could confirm or dis-prove my supposition (citing the sources, providing links).

Silva K said...

Weston Price - Chris Masterjohn's Chart



Affiliate Marketing said...


There is no study that indicates that high doses of K2 (mk-4) causes increased health risk in men as you stated. The Japanese study makes no reference to your subjective opinion either. An exhaustive internet search does not support your claim. In fact, there are specific studies that report NO SIDE EFFECTS at even over 200 mg per day (other than antagonist effects on warfarin and other blood thinners). The reason men are not in the Japanese study that you referenced is that men are not inclined to develop osteoporosis, like women do post menopausal due to associated hormonal changes and their apparent effects on K2.

I take Carlson brand supplement which has 5mg (mk-4). I will have to disagree with Stephen, respectfully, on his dosage warning. Indeed, there are long term studies which demonstrate no ill effects of K2 (mk-4) supplementation in above 45mg. The only warning produced on K or K2 dosage is for those people taking anticoagulants (Warfarin, etc). But, now there are even current studies that support high dosage of K2 with anticoagulants with the anticoagulant adjusted for stability. These studies are important due to the calcification of arteries effect produced by anticoagulants. Additionally, each individual needs to assess their needs as an individual. Some people may have to obviously supplement more if they have a poor diet and are in health crisis showed to be impacted by K2 (MK-4). Higher dosages should not be so cavalierly dismissed or advised against, as sub-optimal dosages will adversely impact the desired effect.

Also, I eat eggs and various meats rich in K2 at various intervals, as suggested by Stephan for natural form food source.

To a commenter regarding MK-7: MK-7 is produced in humans by bacteria in the gut. Studies do not demonstrate great absorption of MK-7. Positive effects of MK-7 consumption is most likely due to conversion to MK-4. Some K1 is also converted to MK-4. K1 is derived from vegetable sources.

montmorency said...

This thread is now quite old, but I see it's still "awake", so I will venture to add a comment:

Someone (in an old comment) said that it wasn't stated on the packet whether Kerrygold butter was grass-fed. Well, I've recently noticed on the packets on sale in England, it is definitely stated that it is grass-fed.

Interestingly, they seem to have re-packaged it recently. For a longish time it came in plastic tubs, which I wasn't keen on for environmental reasons. It's now back in gold-coloured foil-coated paper (also currently at a good price here). I'm guessing that their marketing people have cottoned on to the fact that people now pay attention to things like "grass-fed", which may not always have been the case.

Anchor, New Zealand butter (grass-fed all year round, as has been stated), has become very expensive in the last year (I assume because of the price of oil driving up transport costs). It used to be one of the cheaper butters on sale here. I worry about all the sea(?)-miles (air-miles?) getting it here though.

I tried the German database, and was getting values for Vitamin K a lot lower than reported above. e.g. butter, 7 microgrammes per 100g. Can that be right?

Anonymous said...

I have been reading a lot of comments about stronger nails via ghee or butter. If you want stronger nails that grow fast use MSM powder with freshly made veggie juice and see what happens to your nails! And now my wife and I discovered butter oil and cod liver oil and our health and energy are soaring to new levels. Thanks Dr Price where ever you are!!!

stephers said...

Look what I found.

A 2011 Patent Application Publication for a patent filing by a Big Pharma corp. for a time release version of K2 for osteoporosis.

Gee, do you think doctors will soon start pushing expensive, patented versions of K2 now that Fosamax and other osteoporosis meds have expired patents?

Alexandra said...

I've been taking the cod liver/butter oil blend and my skin has been clearing up. I got hold of Ramiel Nagel's book "Cure Tooth Decay." Great stuff. I've also been dropping all this excess weight.

Christian said...


Do you know if bearfat is a good source of fat-soluble-vitamins, like K2, D and A?

Since a lot of native americans in Canada and north america used it as their primary fat it would make sense if it's filled with these substances.

michael s. said...

Hey i take;

One Drop Contains:
Vitamin K (as Vitamin K-2*) 1 mg.

*Menatetrenone (MK-4)
Other Ingredients: Medium Chain Triglyceride Oil, Mixed Tocopherols.

Thorne Research - Vitamin K2 Liquid 1 fl oz (30 ml)

michael s. said...

Thorne Research - Vitamin K2 Liquid 1 fl oz (30 ml)

stephers said...

Incidentally, I emailed Thorne about the possibility of unnatural isomers in their K2 drops product. Their response was:

"I have forwarded your question to my Medical Advisors. They are asking if you can provide us with a little more information regarding your concerns about the unnatural isomers that you have read on-line."

I wrote back:

"From what I have read, only the trans isomer of vitamin K2 appears in nature, while manufactured K2 can have the cis isomer, and nobody knows what the cis isomer does in the body or whether it will harm, for example, the liver, especially if taken long term the way vitamins tend to be taken. It may accumulate. The recommended dosage of 45 mg per day is already about 90 times what could be gotten from food, so it is a megadosage, but the body at least has the enzymes to process trans K2. It seems to be unknown what happens to cis K2."

That was about a month ago. No reply.

Does anyone know whether the Glakay K2 product used in Japan has cis isomers? Glakay seems to have a good safety record.

After that rat study I am surprised we haven't heard of any human studies about reversing arterial calcification using K2.

gabriEl said...

Hi Stephen,

Thanks for your blogs and the work that you are doing. Just have a few questions, what are your views about the Japanese Natto (from fermented Soy Beans)? I was considering making some and having Natto for breakfast like many do in Japan.. Do you think eating Natto is better than supplementing with the Green Pasture Butter Oil?

Appreciate your input.. thanks.. gabriEl (WPB, FL)

Average Joe Body Builder said...

I was hoping that kale would have vitamin k2, but I guess I was wrong.

SamuelNelson said...

To tell you the truth, I am not much of a biology expert, so some of these comments are going way over my head, but hopefully my comment won't seem too off topic. What wholesale supplements are healthy to eat? I believe a big concern about vitamin supplements is taking too much of a particular vitamin, and some vitamin supplements say they are 150 to 200 percent of the daily norm. Is that healthy?

Francisco said...

I came here because Vitamin K2 actually cures Parkinson disease. I googled "sources of Vitamin K2"
And ended up here. You say in the article "Vitamin K2 It's concentrated in the brain, serving an as yet unknown function." The function seems to be energizing mitochondria.


Rochelle Cashdan said...

For those of us with osteoporosit but try to limit our cholesterol at least partly with a low red meat, low egg, low dairy fat diet, what sources of K2 do you rcommend?

Lorena Alfa said...

I am a woman from Mexico, I've had two pulmonary embolism events and was prohibited to take Vit K and I take anticoagulant Syntrom. On the other hand I have no thyroid or parathyroid so I'm not able to control the calcium levels, I take calcium gluconate and Alphacalcidol as a Vit D and Levotyroxin. I have had calcium deposits in many parts of my body, and because of that I've had 2 cervical surgeries. Now I have Pulmonary Artery Hypertension PH too, and I'm afraid the hypertension comes from calcium deposits in my arteries and my blood clotting too. both I see in your article could come from a lack of this MK-4 lack. I thank you so much for posting this article, I´ll talk to my hematologist on using MK-4 with my anticoagulants and hopefully my PH and all the calcium deposited in my body in parts where it shouldn't be will leave my body and let me live a better, longer life.

Puddleg said...

this is interesting:
vit K1 supplies MK4 in aged rat brain which restores myelin.
Not by the same mechanism (carboxylation) as other Vit K effects.

One role of vitamin E is as a "midwife" in conversion of carotenes to retinol. Without it, antivitamin-A apocarotenoids are formed.

WholeVegan said...

Vitamin K2 is plenty in Natto, soy paste, soy sauce, and other soy fermented products. So vegans have no problem with K2.

Puddleg said...

If they eat those foods. But many vegans either don't have access to Asian products or eat a junk food diet without the meat.
How much K2 in soy sauce?
This source says zero

WholeBodyHealth said...

Research suggests 180mcg of MK-7 per day can reverse areterial plaque =)
Let's go back to eating grass fed animal products for our natural K2!

stern said...

why mk4 is called synthetic,since its from a natural plant tobbaco ?
japanese consumes up to 1000 mg of natto ,but 2 mg mk7 or 50 mg mk4 is already overboard ?

Unknown said...

I read somewhere (I do not remember the source) that MK-7 CANNOT pass through the Blood Brain Barrier but that MK-4 can do so. I have done an internet search but I cannot find any research that confirms this one way or the other. Anyone care to comment on this? Can you provide a link to research on this matter? Some MK-7 manufacturers state that "Vitamin K can pass through the Blood Brain Barrier" without specifically saying that MK-7 can do so. So that is possibly a very misleading statement for them to make wouldn't you say?

stern said...

in the body the mk7 anyhow has to and does convert itself to mk4,so basicaly in the end of the day ,if everything goes right you get it into brain barrier either way

Top Secret said...

Which supplements are good, please recommend a butter pill.

Thili said...

"Vitamin E is mysterious to me. Supplementing with alpha-tocopherol seems to be bad, but the E in foods isn't. It it the mixture of tocopherols/tocotrienols or maybe just the total amount? If it's the type of E, what's the right balance between types?"

Sorry this is a bit late, but some might find this helpful, in regards to vitamin E.

To put it simply:

* Synthetic vitamin E (dl-alpha tocopherol) is less effective and can be toxic.

* Even natural vitamin E (d-alpha tocopherol) in supplement form can be toxic, since it is only 1 member of the entire family of 8. Taking large doses of alpha tocopherol is known to displace gamma tocopherol from the cell membranes. Both are needed to protect against different types of radicals. This is why when vitamin E is ingested from food / natural sources, it is safer and more protective. (You usually get a few, or even all, of the members of the vitamin E family from food sources.) It also explains the paradoxical results in studies that use only alpha tocopherol.

Hope this helps!

Unknown said...

I am excited to learn about K2 . I am concerned about the Cod liver oil as I am allergic to all fish. I have very bad reactions to fish oil so I take flax seed oil. can you suggest a substitute for CLO.

Anonymous said...

Why was only MK4 used in clinical trials in Japan? Anyone know, when it's MK7 that's found in Natto. It seems that MK7 was never really tested in trials and no proof exists that the supposedly more bioavailable form of K-2 (longer chain) is really helpful for osteoporosis or removing calcium from arteries. But we do have studies in the Calcium Paradox Book that Japan's osteoporosis problem is rare in regions where Natto (MK7) is regularly consumed. Anyone know what the real story behind all this is? Why would the Japanese not test MK7 but test MK4 instead, which is more widely available in aged cheese varieties which most Asians don't consume? Very strange, huh?

stern said...

I guess its all about ,where the money is ,mk7 is what is the most widely available as supplement ,
its more cost effective for the consumer ,the mechanistical and epidemiologic evidence for MK-7 is incredibly strong. Carboxylation is the only known physiologic function of vitamin K and MK-7 does it better in vitro, in vivo and in humans. Most epidemiology finds associations with MK-7 not MK-4 or phylloquinone. It's clearly the best choice based on epidemiology and pharmakokinetics.

MK-4 is inferior in all regards. All successful trials use unnatural mega doses (menadione metabolism - probably not a problem at 1000mcg but at 45000? lack of evolutionary adaptation?), usually 45mg, and it's used to treat, not prevent disease. So the data tells us nothing about aging and prevention. We do not suffer from hepatic cancer or osteporosis. So it's clearly inferior for anyone who's not at risk of osteoporosisthe mechanistical and epidemiologic

Unknown said...

Its an interesting point. I don't remember ever having been told I need K2 in my diet before. I guess I'm going to go out, buy some K2 butter and whisk it in my protein shake after workout. Got myself a nice steroid shake!

Mayorc said...

Stephan what about MenaQ7 Menaquinone, are the properties the same as Activator X.
What is the version our body sintenthise in our intestines thorugh bacteria through Vitamin K?
Shouldn't be that the best form ?

Sorry for my poor english.

earthgirl said...

Stephan would you know what is best option if sensitive to dairy. I get mild throat swelling by the next day even with Ghee. GP Butter oil sample smelled rancid and too expensive I think.. Is there (notable) K2 in lambs liver?

Linda said...

Collagen protein supplements supply the body with important amino acids that serve as building blocks....

Austhinker said...

earthgirl: If you're still "listening" to this thread, you might have to research some of the K2 supplements. If you contact the manufacturers,or even the distributors, you should be able to find out whether a particular product is made from dairy, especially if you mention that you have an allergic sensitivity to dairy. The Thorne Research drops, whilst pricey, seem to be most economical serious K2 supplement, so you might want to start your research with them.
Alternatively, you could try Natto - from what I've read the menaquinone 7 gets converted to menaquinone 4 in the body.
Information from an earlier post, reduced to show just mcg K2/100gm:
egg (raw)
chicken 48
duck 45
goose 45
yolk 147
cooked liver
pork 61
beef 81
chicken 87
veal 97

From memory of other tables, lamb (and lamb liver) is around or a bit below beef in K2 levels.

Also, I've found that Kinesiology/Touch for Health can neutralise at least some sensitivities. May be worth trying if you can find a good practitioner.

Austhinker said...

I'm posting this as a separate comment in case it's deleted as an ad.

I consistently find Webvitamins.com to be the best source for online supplements - price-wise and range.

If anyone knows a better value source, I'd appreciate a "heads-up" as I buy a lot of supplements.

Unknown said...

Andrew Hicks asks for a better value source for supplements ordering, and mine is Swansons vitamins, including when buying other brands, which are highly discounted there.

I sometimes also buy from Puritan's on occaission, often finding very good prices there, but I don't find it as easy to figure out what else is in the product, (or that excipentents I don't like are more often in the product). Puritans also has confusing pricing, but sometimes when I work it out, it turns out to be a very good savings; they mostly sell their own brands only though.

So I have come to rely on swansons for most, and ordering on the days that 20% off is offered via the emails sent out. Swanson is willing to send a LOT of emails, so I adjust my "subscriptions" for a lot less of them. I check Amazon for those things that I am not finding at Swansons, and find there are both things priced high and priced low there. I've mostly found good Amazon prices on the things not available through Swansons. The Swanson catolog does not list everything they offer, so using their online site works far better.

I did a comparison at webvitamins of my most frequent purchase, and found it very expensive compared to my experience at swansons. But then, on that one, both the swansons and puritans pride versions are very inexpensive, and all the name brands are considerably more, which is what is offered at webvitamins. The swansons and puritans versions have suited me well for years. I also take a lot of name brands in others things, and find my best prices through swansons, though I have not compared with Amazon item by item.

I hope this will be helpful to some.

Unknown said...

With regards to stephers concern about cis isomers of K2 as unnatural, LEF says (by phone today) that their manufactured K2-4 is trans isomers.

Tootie said...

Quote from article at top, "As long as you eat a natural diet containing some vegetables and some animal products, and lay off the processed grains, sugar and vegetable oil, the micronutrients will take care of themselves." Just want to challenge this, the very nutrient you are writing about, K2, is thought to be no longer available in sufficient quantities in diet for the average person, according to "Rheaume-Bleue" in the book, Vitamin k2 and the Calcium Paradox. Also Dr. Carolyn Dean asserts that extra magnesium is needed even for those who are deliberately trying to have a magnesium rich diet.

nutritionist said...

Can we be sure that the mk-4s sold in the market today are actually the all trans-isomer? anyone knows which company makes mk-4? maybe the reason y such high doses of mk-4 are needed for therapy is because the manufactured mk-4s today are not totally the natural all trans isomer.

Anjali said...

Hi Stephan, can you elaborate on this link ?


whisperingsage said...

What I would like to know is how through the years in the USA,what year was it they completely removed dairy cows from pasture? I was born in the 60's had excellent dental health all my life- until age 33 when I had my first adult cavity (caused by, no surprise, trying to live on Top Ramen due to lousy pay). I remember as a child, the milk coming to the doorstep in glass bottles. My mother fed us liver about once a week. But milk was daily. Cheese almost daily. Nothing special. Why was it I could have such good teeth on normal food THEN with extra care being taken to have special pasture raised butter and special pasture raised cheese etc? were cows simply being raised more on pasture in the 60's, 70's and 80's?

John222 said...

If you have a stent in your heart, will taking vitamin K2 be dangerous? Can anybody who has a stent give me any information about this?