Vitamin K2: The Missing Nutrient


A study recently published by the European Prospective Investigation into Cancer and Nutrition (EPIC) has revealed that increased intake of vitamin K2 may reduce the risk of prostate cancer by 35 percent. The authors point out that the benefits of K2 were most pronounced for advanced prostate cancer, and, importantly, that vitamin K1 did not offer any prostate benefits.

The findings were based on data from more than 11,000 men taking part in the EPIC Heidelberg cohort. It adds to a small but fast-growing body of science supporting the potential health benefits of vitamin K2 for bone, cardiovascular, skin, brain, and now prostate health.

Unfortunately, many people are not aware of the health benefits of vitamin K2. The K vitamins have been underrated and misunderstood up until very recently in both the scientific community and the general public.

It has been commonly believed that the benefits of vitamin K are limited to its role in blood clotting. Another popular misconception is that vitamins K1 and K2 are simply different forms of the same vitamin – with the same physiological functions.

New evidence, however, has confirmed that vitamin K2’s role in the body extends far beyond blood clotting to include protecting us from heart disease, ensuring healthy skin, forming strong bones, promoting brain function, supporting growth and development and helping to prevent cancer – to name a few. In fact, vitamin K2 has so many functions not associated with vitamin K1 that many researchers insist that K1 and K2 are best seen as two different vitamins entirely.

A large epidemiological study from the Netherlands illustrates this point well. The researchers collected data on the vitamin K intakes of the subjects between 1990 and 1993 and measured the extent of heart disease in each subject, who had died from it and how this related to vitamin K2 intake and arterial calcification. They found that calcification of the arteries was the best predictor of heart disease. Those in the highest third of vitamin K2 intakes were 52 percent less likely to develop severe calcification of the arteries, 41 percent less likely to develop heart disease, and 57 percent less likely to die from it. (Geleijnse et al., 2004, pp. 3100-3105) However, intake of vitamin K1 had no effect on cardiovascular disease outcomes.

While K1 is preferentially used by the liver to activate blood clotting proteins, K2 is preferentially used by other tissues to deposit calcium in appropriate locations, such as in the bones and teeth, and prevent it from depositing in locations where it does not belong, such as the soft tissues.(Spronk et al., 2003, pp. 531-537) In an acknowledgment of the different roles played by vitamins K1 and K2, the United States Department of Agriculture (USDA) finally determined the vitamin K2 contents of foods in the U.S. diet for the first time in 2006. (Elder, Haytowitz, Howe, Peterson, & Booth, 2006, pp. 436-467)

Another common misconception is that human beings do not need vitamin K2 in their diet, since they have the capacity to convert vitamin K1 to vitamin K2. The amount of vitamin K1 in typical diets is ten times greater than that of vitamin K2, and researchers and physicians have largely dismissed the contribution of K2 to nutritional status as insignificant.

However, although animals can convert vitamin K1 to vitamin K2, a significant amount of evidence suggests that humans require preformed K2 in the diet to obtain and maintain optimal health. The strongest indication that humans require preformed vitamin K2 in the diet is that epidemiological and intervention studies both show its superiority over K1. Intake of K2 is inversely associated with heart disease in humans while intake of K1 is not (Geleijnse et al., 2004, pp. 3100-3105), and vitamin K2 is at least three times more effective than vitamin K1 at activating proteins related to skeletal metabolism. (Schurgers et al., 2007) And remember that in the study on vitamin K2’s role in treating prostate cancer, which I mentioned at the beginning of this article, vitamin K1 had no effect.

All of this evidence points to the possibility that vitamin K2 may be an essential nutrient in the human diet. So where does one find vitamin K2 in foods? The following is a list of the foods highest in vitamin K2, as measured by the USDA:

Foods high in vitamin K2

  • Natto
  • Hard cheese
  • Soft cheese
  • Egg yolk
  • Butter
  • Chicken liver
  • Salami
  • Chicken breast
  • Ground beef

Unfortunately, precise values for some foods that are likely to be high in K2 (such as organ meats) are not available at this time. The pancreas and salivary glands would be richest; reproductive organs, brains, cartilage and possibly kidneys would also be very rich; finally, bone would be richer than muscle meat. Fish eggs are also likely to be rich in K2.

It was once erroneously believed that intestinal bacteria are a major contributor to vitamin K status. However, the majority of evidence contradicts this view. Most of the vitamin K2 produced in the intestine are embedded within bacterial membranes and not available for absorption. Thus, intestinal production of K2 likely makes only a small contribution to vitamin K status. (Unden & Bongaerts, 1997, pp. 217-234)

On the other hand, fermented foods, however, such as sauerkraut, cheese and natto (a soy dish popular in Japan), contain substantial amounts of vitamin K2. Natto contains the highest concentration of K2 of any food measured; nearly all of it is present as MK-7, which research has shown to be a highly effective form. A recent study demonstrated that MK-7 increased the percentage of osteocalcin in humans three times more powerfully than did vitamin K1. (Schurgers & Vermeer, 2000, pp. 298-307)

It is important to note that commercial butter is not a significantly high source of vitamin K2. Dr. Weston A. Price, who was the first to elucidate the role of vitamin K2 in human health (though he called it “Activator X” at the time) analyzed over 20,000 samples of butter sent to him from various parts of the world. As mentioned previously in this paper, he found that the Activator X concentration varied 50-fold. Animals grazing on vitamin K-rich cereal grasses, especially wheat grass, and alfalfa in a lush green state of growth produced fat with the highest amounts of Activator X, but the soil in which the pasture was grown also influenced the quality of the butter. It was only the vitamin-rich butter grown in three feet or more of healthy top soil that had such dramatic curing properties when combined with cod liver oil in Dr. Price’s experiments and clinical practice.

Therefore, vitamin K2 levels will not be high in butter from grain-fed cows raised in confinement feedlots. Since the overwhelming majority of butter sold in the U.S. comes from such feedlots, butter is not a significant source of K2 in the diet for most people. This is yet another argument for obtaining raw butter from cows raised on green pasture.

New research which expands our understanding of the many important roles of vitamin K2 is being published at a rapid pace. Yet it is already clear that vitamin K2 is an important nutrient for human health – and one of the most poorly understood by medical authorities and the general public.

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Comments Join the Conversation

  1. Mr Jinxx says

    Absolutely right. I’m surprised no-one has mentioned juicing, which will crush the cell walls of those organic greens to release the enzymes, and will therefore give you all the K1 you need – which your body should convert into the K2 it requires in a perfectly natural way

    I did do a short video for my son (hence the personal nature of my commentary, sorry!) who is keen on juicing since his wife contracted cancer and they read up on the benefits of juicing, which if you can be bothered you can watch here. Bad sound at the end but the product it produces is like rocket fuel and absolutely packed with nutrition.

    The China Study is a fascinating and potentially life changing book I found. The proteins in animal flesh are really not good for you, and nowadays in particular, the amount of chemicals, pesticides, hormones, antibiotics etc in animals (and through them, dairy) is outrageous. Do have a read if you can.

    There’s no magic bullet I’m afraid – not K2 not juicing nor anything else – but I’m utterly convinced that natural organic whole foods (fruit veg nuts seeds etc) should form the basis of your diet and your body is such an incredible machine that it will take things from there, and other than in extreme cases it will regulate your requirements without the need for supplements.

    And if you can juice those greens to release the trapped enzymes (which only ruminants do completely) then you will benefit so much, so fast that you’d be amazed. Not to mention the energy boost it gives you. A little calf turns into a raging bull just by being able to digest fully its grass. Just imagine what benefits we get if we break down kale spinach broccoli celery etc in a juicer … and no, you won’t grow horns or a massive willy.

    On the subject of dairy, again the China Study is an illuminating read. Leaving aside the very important matter of animal protein and fat being bad for you (as opposed to good fats like Flax Seed Oil) cows and sheep and chickens tend to be fed on corn or similar products, which are encouraged for commercial reasons to grow quicker taller closer together etc by being modified genetically in some cases and being covered in all sorts of different chemical fertilisers and pesticides and goodness knows what else to combat bugs and insects and bacterial infection, and then processed and fed to the animals (who aren’t made to eat this stuff naturally) and so need antibiotics and hormones to try and combat this. This finds its way into the flesh eggs and milk of course, and the milk for example is then pasteurised to counter some of the bacterial problems but which also kills the enzymes etc, and the resulting thin blue liquid is coloured and processed to look like the milk you buy in your supermarket – made by cows for the original purpose of growing little calves into much bigger calves very quickly, rather than containing the proteins etc which are good for us humans – and which the milk marketing folk (who commission the surveys and research) tell us quite erroneously that our children need for healthy bones and teeth, and even provide it free at some schools to imprint upon us the benefits of this bad white liquid.

    Im not promoting being a vegan because although I’ve been pretty successful in cutting out almost all dairy almost all the time, I do love fish and I will still occasionally eat some meat because it tastes so damn good, but the more I keep reading about the damage that eating animal flesh does to us, and the more I realise that, contrary to what I always believed, we aren’t designed to be carnivorous, the taste of animal flesh is losing a lot of its charm.

    No we’re not carnivores. And only just omnivores in truth. I think we were designed as primarily vegetarian with the capability of eating and digesting small amounts of meat in emergencies. We don’t have carnivores’ teeth – try taking a bite out of a buffalo or a cow or a wild boar and see what happens … you’ll win yourself a good kicking. Those teeth are meant to bite and chew apples and carrots etc. Our stomachs aren’t acidic enough to be true carnivores – they are a fraction of what true carnivores are like, so it takes us ages and a prolonged period of acid production to break down and digest a big bite of juicy steak, and that is not a good thing. Acid conditions in our bodies create conditions that cancer loves. And our intestines aren’t short like real carnivores – they’re very long. The animal fat stays in us for a long time. Too long. Any kind of fat that is solid at body temperature will tend to solidify inside our arteries and elsewhere … the fat after being “digested” separates out like an emulsion, and so, ladies and gentlemen who like their meat,
    welcome to heart and circulation problems.

    This rather old but nonetheless relevant and current video clip by an extreme but clever and rather amusing doctor/prof/boffin does make the above points rather better than I have …

    Anyway, back to the K2, I do think there’s a danger in rushing into supplements and thinking they’re a cure-all, when the #1 best thing you can possibly do for yourself is to take this guy’s advice and lose the animal/dairy as near to completely as you can, get stuck into organic whole foods (fruit veg nuts seeds etc) as much as you can, and juice those greens to get the most benefit you can … and that’s a massive benefit.

    Me, I hate celery and broccoli but if I grind them up in a juice, mixed with apple, carrot, pineapple, lemon and some ginger and a bit of turmeric (not enough to turn the green juice brown, just because it looks like pond water!) and stick some ice cubes in it – or put it in a cocktail shaker, which is what I do – then it really does taste really refreshing and cleansing and, being a liquid, it goes straight through your stomach in no time and is immediately absorbed and into your blood in about 15 minutes. You get an immediate energy and nutrition boost, and once you start this juicing of fruit/veg, it’s difficult to stop. And that’s a Good Thing!

    So try getting your K2 through juicing those green leaves – watch that Vimeo vid clip above – you’ll see just how much green stuff you use to get one incredibly concentrated juice. Insanely good! And lay off the supplements if you can – the nutritional route to health is horribly misunderstood and overlooked, particularly by western doctors etc who are trained from the outset to spot a problem and try and cure it with a pill. Instead of realising that with the correct nutrition, your body can balance itself and cure the majority of its ailments itself. Not all the time, sure, and not in extremis, but for most of us it can be quite literally a life saver.

    • stenB says

      Please google Denise Minger China Study and a much different picture emerges. One where high carb consumption was ignored when statistical analysis of animal protein was analysed, plus a number of other things. Regarding pesticides it may also be worth to point out that when animals eat pesticide impregnated foods, grains that humans eat usually also contain a lot of pesticides. That non-organic grain nowadays also is sprayed with Roundup as a last kill to increase yield make at least for me all grains off limits. I also warmly recommend a read of “The Big Fat Surprise” by Nina Teicholz. A brilliant book. Cheers!

    • Tired of vegans says

      Veganism has been thoroughly debunked. The China Study has too. Humans are not natural vegans or vegetarians, nor are humans well-designed for eating grains. Take a look at the work of Dr. Weston Price, and quit spreading misinformation, please.

    • Migby says

      “Oxalic acid present in greens and other foods has the potential to bind with calcium, magnesium, iron, zinc and copper in our intestines to form oxalates, insoluble salts, thus interfering with the absorption of these minerals and making them unavailable for the body to use. It doesn’t, however, affect the absorption of calcium in other foods consumed at the same meal.”

      Article goes on to say best bet is to rotate high oxalic greens with low, and/or steaming greens for 4 or less minutes and eating a little more than you would drink raw to make up for loss of nuts’ from heat. . .

      • Adam Waddington says

        Unless you have kidney stones, Oxalate content does not matter. Your kidney will process them just fine.

        • Brendanyc says

          Your kidneys may not be damaged by oxalates–the evidence is not there–but the difficulty with oxalates remains–the essential minerals that bind with oxalic acid become unavailable for our bodies. This is why spinach, although high in iron, is such a poor therapy for anemia.
          I believe in eating greens–they are good for us!–but the danger in eating a diet too heavily dependent on them is clear. Balance, moderation in all things is key. Yes, even moderation in such good stuff as spinach or kale.
          oh well…..

    • Bill says

      You talk about using massive amounts of vegetable produce to get a glass of juice? Really? And that’s sustainable in what way? Throw out all that produce? Imagine if the whole world were to take your advice. Just eat your veggies. And meat.!!!!!!

  2. Lisa Intemann says

    I’m a neophyte to the topic of vitamin K2, but finding it enormously interesting. Am now embarking on fermentation beyond simple yoghurt – starting with kefir and vegetables. Love the idea that we can get K2 from everyday pleasures, like gardening in good dirt, plus eating yummy stinky cheese and tart milk!!

    As I presently understand it, there are different varieties of K2, depending on the food. There’s MK-1 from plants, and MK-4 from animal products like eggs, chicken breast, offal, etc. But we can also get different MK-n variants from fermented foods, depending on the particular fermentation bacteria – each possibly with its own nutritional benefit.

    Is that how you understand it?


    • Sheena says

      Yes, kefir is a fermented product with beneficial nutrients including vitamin k2. I believe Chris Kressor wrote an article on this.

  3. Jack Cameron says

    Update on vitamin K2 content of fermented dairy:

    Data on vitamin K2 is a moving target. From the year 2000 until 2013 the vitamin K2 content of vitamin K2 from fermentation was widely considered to be negligible based based on a single sample in a study of K2 content of foods by Schurgers et al, Netherlands. It is a fact, however, that all lactose fermenting bacteria must produce vitamin K2 to survive as it acts as an essential electron transfer agent in their respiratory chain. A recent (2013) study by Manoury of France found the median content of vitamin K2, subtype MK5 to MK10 of 21 samples of “mesophillic fermented milk” (yogurt) was 12 mcg/100 grams or 12 times that previously estimated. The MK-4 content of fermented milk is about 1 mcg/100 grams which brings total vitamin K2 content of fermented milk to 13 mcg/100 grams which equates to about 21 mcg/100 calories.

    The 2000 Schurgers study gave the fermentation derived vitamin K2 content of cheeses as follows: hard cheese 72, mcg/100 grams, soft cheese 52, mcg/100 grams, and curd cheese. 25 mcg/100 grams. In contrast, the median fermentation derived vitamin K2 content of 62 samples of cheese in the subject Manaury study was much lower, 26 mcg/100 grams. The median MK-4 content of cheese is 6 mcg/100 which brings total vitamin K2 content of cheese to 32 mcg/100 grams which equates to 8 mcg/100 calories compared to 21 mcg/100 calories in fermented milk. (PMID: 23332840) So the vitamin K2 content of yogurt on a per calorie basis is about 2.5 greater than the average K2 content of cheese.

    The vitamin k2 subtypes produced by fermentation, MK-5 to MK-10, have longer side-chains and are more lipid soluble than “short chain” MK-4 and are therefor more bio-available and have been found to more effectively activate osteocalcin than MK-4 found in animal fats. MK-4 has a poor bio-availability in humans and is undetectable at a nutritional level dose (45–90 μg/day), whereas long chain MK-7 is well absorbed and detectable in the blood at nutritional levels. Because all vitamin K subtypes, including MK-1 from green plants and MK-8 and MK-9 from lactose fermentation, can be converted to MK-4 in vivo, MK-4 is thought to have specific functions other than γ-carboxylation of vitamin K-dependent proteins. In rats, “long chain” MK-n from fermented foods has been found to be a better supplier for MK-4 in vivo than MK-4 itself. (PMID 23140417). Thus the long chain MK-7 from natto and the MK-8 and MK-9 from lactose fermentation appear to be superior in function to MK-4 from animal fats.

      • Jack Cameron says

        Vitamin K2 is not sensitive to heat, so K2 is not damaged by pasteurization. As for studies on the K2 content of fermented greens, it has been determined that sauerkraut contains a small amount of vitamin K2 mostly from fermentation. Other than that, I am not aware of any studies concerning the vitamin K2 content of fermented greens. Natto, a fermented soy product that is consumed in some parts of Japan, contains more vitamin K2 than any other food, mostly subtype MK-7. MK-7 has been extensively studied and, like MK-8 and MK-9 from lactose fermentation, is more effective than MK-4 from animal fats in activating vitamin K dependent proteins.

        There are several recent studies that found that those who consumed fermented dairy, compared to those who consumed no fermented dairy, had significantly reduced risk of mortality and bone fracture. (PMID 25352269), significantly reduced incidence of heart attacks (PMID 23173172), and significantly reduced incidence of type 2 diabetes (PMID 22760573). The first two of these were conducted in Sweden while the third study was done in eight European countries including Sweden.

        In the first of the studies, in which 61,433 women followed for 20.1 years, there was an inverse association between intake of cheese and fermented milk products and risk of fracture rates and total mortality. For each serving of fermented yogurt or cheese the rate of fractures and mortality was reduced by 10 to 15%. Consumption of fermented milk products (soured milk and yogurt) indicated a negative relation with both oxidative stress and inflammatory markers.

        In sharp contrast, a positive association between non-fermented milk intake and total mortality as well as fracture, especially hip fracture was observed. In women, higher rates were observed for death from all causes (adjusted hazard ratio 1.15, for each glass of milk), cardiovascular disease (1.15 for each glass of milk, and cancer (1.07 for each glass of milk). For women who consumed three or more glasses of milk a day the hazard ratio for any fracture was 1.16 and for hip fracture was 1.60. In a group of 45,339 men with a follow-up of 11.2 years, the excess risk was less pronounced than in women.

        In summary the study showed that consuming fermented dairy decreased mortality and fracture rates while consuming non-fermented dairy increased mortality and fracture rates. The authors made no mention of vitamin K2 as a possible cause of of the benefits experienced by the fermented dairy consumers and frankly their explanation made no sense. In my opinion, the reduction in mortality rates among those who consumed fermented dairy compared to those who did not was clearly driven mainly by the vitamin K2 from lactose fermentation. I have no idea why those who consumed non-fermented milk, compared to those who consumed no non-fermented milk, experience increased risk of mortality and fracture.

        It appears that those who “don’t do dairy” really miss out on significant health benefits that are provided by fermented yogurt and cheese.

        • Caroline Michelle says

          Well, I would love to eat fermented dairy but have autoimmune issues and am somewhat afraid that the kasein and growth factors in dairy will trigger this. What’s your take on that? The kasein and other stuff don’t go away because of fermentation, right?

          • Jack Cameron says

            Caroline Michelle,

            Actually, beta-casomorphin-7 (the “milk devil”), growth factors, and lactose are all degraded by lactose fermentation so the problems do go away while the the beneficial “long chain” vitamin K2 is synthesized. I will post supporting data later.

            The lactose in yogurt is digested more efficiently than other dairy sources of lactose because the bacteria inherent in yogurt assist with its digestion. The bacterial lactase survives the acidic conditions of the stomach, apparently being physically protected within the bacterial cells and facilitated by the buffering capacity of yogurt. Yogurt also contains more vitamin K2 per calorie than cheese. The synthesis of vitamin K2 in lactose fermentation does not require the presence of fat, but vitamin K2 is a fat soluble vitamin and is absorbed far better from full fat yogurt compared to low fat yogurt. The best yogurt is full-fat yogurt made from pastured animals that contains no additives. Almost all yogurt in the US has been described as “junk food” because it is non fat or low fat and contains sugar and additives such as carrageenan and dried milk solids in an effort to make it taste better. I believe that most yogurt available in Sweden is full fat without additives. Yogurt is very easy to make.

            • Caroline Michelle says

              Thanks again for useful information! We actually have a lot of junk yogurt in Sweden too, with sugars and other stuff. I made my own yogurt from high fat milk, non homogenized (but pasteurized though…). How long time does it take before all the bad things (kasein, lactose etc) are removed from the milk/yogurt – is is already when the consistency has turned more solid? And what happens with these bad guys – are they consumed by the bacterias?

          • Julielu says

            I cannot enjoy dairy yogurt without swollen tonsils / sore throat every time, which is same as if i have dairy chocolate, butter, gelatine, or beef. If there is known allergy to milk / beef protein, I am not certain that the “problems will go away” ENOUGH, to not cause a reaction to consuming dairy for K2. :(

            • Gloria says

              Hey Julielu,
              It’s my understanding, (from the few research papers I could find!), that if you ferment milk with Kefir grains,(ABSOLUTELY NOT YOGHURT), that the proteins get broken down into their component aminos, so the allergy to the problem molecule ceases to exist as that molecule is degraded by the bacterial digestion process. I would always recommend anyone with allergies like myself, to do a second ferment of at least 24 hours. I have had no problems thus far.

              I would not attempt it if you are likely to have a life-threatening reaction, however if you have ‘nuisance’ symptoms, it’s up to you if you’d like to try it or not.

              Please only use kefir for that, I’m led to believe that the yoghurts don’t have enough variation in the bacterial spectrum to effectively blast apart all the proteins. I soak all my gluten flours in kefir as well, and have had no sign of my gluten problems or my dairy issues.
              I do use a2 milk, more to preserve the original a2 producing cows, as the protein gets blasted down anyways.

              It’s actually easier for your body to digest these protein builder aminos in reduced form, anyway.

          • Luke says

            Do you eat any type of grain ? then remove it frome your diet. . . Just my experince i have hade skin problems for 5 years now & BOOM my skin has cleard up from removing the GMO Grains & Organic grains r a no no too + no sugar too + you need to up you Glutathion & SOD = superoxide dismutase :)

        • Julielu says

          If the fermenting bacteria in sauerkraut produce K2 feeding on cabbage which is relatively low in ‘greens’ value, perhaps it is a logical jump to try making sauerkraut including outer darker leaves of cabbage and or kale, spinach. I have noticed an increasing strength of fingernails over the past 12 months of just using vinegar Kombucha daily on my salad and wonder whether the lactic bacteria are producing K2 even in kombucha?.

          Having realised a likely K2 deficiency from 30 + years of Pritikin and low fat and no beef /dairy diets and having had many very slow to heal joint injuries – tendons& ligaments of the knees, shoulders, fingers – as well as multitudes of dental caries >50, it’s beginning to make sense that my body has been deprived of the fat soluble vitamins that until recently have received little exposure.

        • Rebecca Oshiro says

          Jack, you clearly know your stuff! Thank you for your thoughtful posts. I particularly appreciate you providing the Pubmed IDs. If you have time please drop me a line at orohound at gmail (don’t want to type out the actual e-mail here). I’d love to share references to nutrition literature.

    • Willy says

      Your statement that “yogurt contains vitami K2 is wrong! By definition (Websters), yogurt is made from thermophilic bacteria (optimum temperature 100 to 122 degrees F) which is NOT known to produce vitamin K2. In contrast, the vast majority of hundreds of different types of fermented milk from around the world do produce vitamin K2 as they are made from mesophilic bacteria (optimum temperture 77 to 86 degrees F). Only “yogurt” and a few uncommon cheeses are made with thermophilic bacteria that do not synthesize vitamin k2. While “yogurt” may have many beneficial properties, vitamin K2 content is not among them.

      In the Manaury study, the 21 samples of “mosophilic fermented milk” did not include yogurt which is made from thermophilic bacteria. A quote from the study:

      “Eight fermented dairy products did not contain detectable amounts of vitamin K2: 5 TFM (TFM1 to TFM5), 2 Comté cheeses (HardC-Co1 and HardC-Co2), and 1 Mozzarella cheese (Mozz). Similarities in cheese process explain this absence of vitamin K2. For these types of products, usually only thermophilic species (Streptococcus thermophilus, Lactobacillus delbrueckii, Bifidobacterium) are used as lactic acid bacteria starter (Fox et al., 2000), and those thermophilic species are not known to be vitamin K2 producers (Collins and Jones, 1981; Morishita et al., 1999). This is also the case for a yogurt-type product also made with pure thermophilic species (Hirauchi et al., 1989; Koivu-Tikkanen et al., 2000).All other fermented dairy products evaluated in this study contained some vitamin K2; 60% of the products had >100 ng/g, a high value for animal products (Koivu-Tikkanen et al., 2000). All of those products contained mesophilic lactic acid bacteria species as starters and especially Lactococcus spp., which are reported to be the source of vitamin K2 (Collins and Jones, 1981; Morishita et al., 1999).”

      Check it out!

    • JonGrant says

      Slight niggle: Yogurt is not a mesophilic fermentation, it’s considered thermophilic since it’s mostly done over 40C.

  4. Caroline Michelle says

    Are vitamin K2 sensitive to heat? I love liver but never tried it raw, might be a new experience though. Cheers from Sweden

  5. Joe Cave says

    There is a wealth of peer reviewed articles available online pertaining to all forms of Vitamin K and the wide spectrum of health benefits. Some are open access and some require a payment or subscription to procure. The latter usually have an informative abstract that is available free. Given the abundance of information available it is a shame that some of those who post haven’t “done their homework”.

  6. Joe Cave says

    Sudy showing the benefits pf K2-MQ7 to Cardiovascular Health

    NattoPharma is excited to share that the study proving MenaQ7 Vitamin K2´s cardiovascular benefits has published in the prestigious medical journal Thrombosis and Haemostasis (online ahead print).

    In the study titled “Menaquinone-7 Supplementation Improves Arterial Stiffness in Healthy Postmenopausal Women”:

    • 244 healthy post-menopausal women were randomly assigned to take 180 mcg of MenaQ7 daily for 3 years, or placebo capsules.
    • 93% of the participants completed the 3-year study.
    • Results confirm that MenaQ7 Vitamin K2 supplementation not only inhibits age-related stiffening of the artery walls, but also made a statistically significant improvement of vascular elasticity.

    “This is the first study showing that long-term use of vitamin K2 in the form of MK-7 beneficially affects cardiovascular health,” says Cees Vermeer, renowned vitamin K2 scientist and Chief Innovation Officer at the R&D Group VitaK of the Maastricht University Holding (the Netherlands), who led the study’s research team.

    This is the same cohort that participated in the study proving MenaQ7’s bone benefits that published in Osteoporosis International in 2013.

    “Observing changes in heart and bone health takes time,” says Hogne Vik, NattoPharma CEO. “Our patience and perseverance has paid off with a study accepted by a highly prestigious medical journal that proves what we have known all along: that MenaQ7 Vitamin K2 truly delivers benefits for hearts and bones.”

    With this important publication in place, the overall market for MenaQ7 Vitamin K2 continues to expand, as solid proof of our product´s heart benefits are confirmed.

    To review the study online prior to its publication in the May 2015 issue of Thrombosis and Haemostasis, click here . For more information on MenaQ7® Vitamin K2, visit

  7. Matt says

    I don’t get how this vitamin isn’t found typically in U.S. diets when the foods listed are some of our most commonly consumed.

    • Mom2e says

      My guess, it’s the same for why US commercial butter (dairy) not being a good source. Most cattle, poultry, etc. in US are raised in Contained Animal Feedlots (CAFO’s). Cows, evolved to eat grasses are fed cheap subsidized corn & soy, (causes infections & requiring antibiotics) to fatten & bring to slaughter in half the time, compromises/changes the final product (i.e. Butter, cheese, meats, etc). Just my guess tho.

  8. Joe Cave says

    See Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women, its an open access article and may help those who are undecided to make the right choice.

  9. Patrice Conklin says

    I started taking K2 150mcg about a month ago, about 2 weeks ago I developed horrible heart palpitations. I had an EKG which was fine, I’m reading a lot about this vitamin causing heart issues. I stopped taking it 3 days ago, does anybody know how long this will take to get out of my system ?

    • Annie says

      Pat ,
      You have made the same mistake many people here do, and that is calling it, K2, what you took is K2 MK-7,..and you took TOO Much,.

      Take K2 MK -4…which takes the calcium to your bones, and Not you only has a shelve life of about 4 hours …

      There are a few types of K, so we all have to be more pacific about what K you talking about…???

      That said, K2 MK-7 stay in the body allot longer, and take a small amount, maybe every coupe of days. It can speed up you heart rate & some people cannot take it…I for one..

      Pat if you read more posts here , I have said this before…

      Take care..

      • juluelu says

        pls reference your information.. i have yet to see a distinction between fermented product k2-m7 and animal fat k2-m4 with respect to their use in the human body

      • julielu says

        ? mk-4 shelf life 4 hours ? unlikely. Its reported to have ashort life in human body.
        mk-7_how does it speed up heart rate? Or why do you day that. ?
        did u mean to imply that mk-7 takes calcium to arteries and that mk -4 does not. i cant verify that.

        • Yosako says

          MK-7 takes calcium FROM arteries to the bones just like MK-4 does. However MK-7 dosages are much lower (around 100 mcg / day) than MK-4 (used for ostheoporosis up to 45 mg /day in three divided doses) since MK-7’s half life is much longer (days) than MK-4 (a few hours).

      • What says

        “shelf life” and “pacific” ? These two major errors made me doubt the rest of your entire post I’m afraid. I think you were going for “half life” and “specific”.

  10. Beth Stamkos says

    Hi Chris, I was taking a combination of K2, vit E drops and Vit D and also my normal fish oil and pro- biotics, I started taking them as my younger brother had open heart surgery for blocked arteries on left side of his heart and was told it was hereditary. I started to have really bad panic attacks as soon as I lay down at night with tremors and sweats and no sleep this continued every night till I stopped taking them, wondering if you know which of these it would be or the combination. Thanking you for your time Beth

  11. Joe Cave says

    also see

    Structure, Absorption and Functions of Soyasaponins and Vitamin K2(Menaquinone-7)
    Toshiro Sato
    and Shuichi Kamo
    Fine Chemical Laboratory, J-OIL MILLS, Inc., Nakashinden 1746, Fukuroi-city, Shizuoka 437-1111
    Soyasaponins: Soyasaponins are triterpene glycosides that possess an oleanane-type aglycone with 1 or 2
    polysaccharide chains. Due to differences in the aglycone compounds, soyasaponins are mainly classified as group A
    or B soyasaponins. Soyasaponins, especially group B soyasaponins, have been reported to have several physiological functions such as antioxidative, cholesterol-lowering, antiviral, anti-inflammatory, renin-inhibiting, hepatoprotective, and antitumor effects. We found that group B soyasaponins are more readily absorbed than group A soyasaponins, which may explainwhy group B soyasaponins exhibit more potent effects.
    Vitamin K2 : Vitamin K is a cofactor required for post-translational gamma-carboxylation of vitamin K-dependent proteins, including coagulation factors, anti-coagulation factors, osteocalcin (OC) in bone, and matrix Gla proteins (MGP) in arteries. Among major vitamin K homologues in foods, only vitamin K2as menaquinone-7 (MK-7) can activate osteocalcin, which modulates bone structure at nutritional doses. Vitamin K2 also induces collagen accumulation in bone, contributing to bone quality and strength. In addition, MK-7 activates MGP, an artery
    calcification inhibitor, and is reported to be associated with the prevention of cardiovascular diseases. The higher
    efficacy of MK-7 compared to other vitamin K homologues is due to the better absorption and longer half-life of MK-7.
    (Accepted Mar. 6, 2013

    • Ruth says

      Can anyone kindly tell me if the k2 is preserved in Natto after it has been frozen. My local Asian Market carries Natto in the freezer. Thank you!

      • C says

        I received the following email from the leading authority on K2.

        “In contrast to some other vitamins, vitamin K2 is very stable. It is very well conserved by freezing. We keep our samples frozen for years, and there is no loss of MK-7. The only precaution you have to take is to prevent long exposure to daylight. All K vitamins are sensitive to UV radiation.

        So you did exactly the right thing. Natto is so rich in MK-7 that it does not make sense to combine natto eating with an MK-7 supplement. Just as an illustration: most supplements contain 45 micrograms of MK-7. This amount is also reached by eating 4 or 5 grams of natto.

        If you get accustomed to the taste of natto, this is the cheapest way of getting MK-7 in significant amounts. I recommend a daily dose between 200 and 400 micrograms of MK-7 for healthy subjects. Patients may require more. And if you receive blood thinning medication you should consult your medical doctor before taking vitamin K at all.

        With kind regards,


        CEES VERMEER, PhD, Associate Professor of Biochemistry

  12. Joe cave says


    The Antiosteoporotic Effects ofCheonggukjangContaining Vitamin K2
    ( Menaquinone-7) in Ovariectomized Rats
    Wei-Jie Wu,1,
    *Hwa-Young Lee,
    *Geum-Hwa Lee,
    Han-Jung Chae,
    and Byung-Yong Ahn
    Department of Food Science & Biotechnology, Chonbuk National University, Iksan, Korea.
    Department of Pharmacology, Institute of Cardiovascular Research, School of Medicine,
    Chonbuk National University, Jeonju, Korea.
    Department of Oriental Medicine Resources, Chonbuk National University, Iksan, Korea.
    ABSTRACT The effect of dietary vitamin K2 (menaquinone-7, MK-7) and cheonggukjang(CGJ) on the prevention of
    ovariectomy (OVX)-induced bone loss was studied in rats. Female Sprague-Dawley rats were divided into eight groups: sham-operated; OVX control; OVX treated with MK-7 at doses of 2, 4, and 8lg/day; and OVX treated with CGJ at doses of 0.063,
    0.125, and 0.250 g/day referenced to MK-7 levels at 2, 4, and 8lg/day, respectively. After 8 weeks of treatment, the
    preventive effects of MK-7 and CGJ were evaluated by measuring body weights, serum levels of bone turnover markers, bone
    mineral content (BMC), bone mineral density (BMD), trabecular microarchitectural properties, and bone histological char-acteristics. Our results showed that rats treated with a high dose of MK-7 (8lg/day) exhibited a minor inhibitory effect on
    OVX-induced bone loss, as indicated by a significant increase in trabecular number, as well as BMC and BMD (P<.01).
    Moreover, the preventive effects of MK-7 were augmented by administration of CGJ at the same MK-7 dose. In addition, the
    preventive effects of CGJ were shown to be dose dependent, with the highest dose (0.250 g/day) significantly (P<.01)
    increasing BMC and BMD by 31.8% and 47.6%, respectively. In summary, these results suggest that administration of CGJ
    containing abundant levels of MK-7 may be a promising approach for the treatment and prevention of osteoporosis.

    Menaquinone-7 contains seven isoprene units and is abundant in fermented Asian soybeans, such as natto in Japan and cheonggukjang (CGJ) in Korea.

    A previous study has
    shown that habitual intake ofnattocontaining abundant levels
    of MK-7 was beneficial for bone health in elderly men.

    Likewise, higher levels of MK-7 resulting from natto consumption may contribute to a relatively lower risk of fractures in Japanese women.

    Bone loss in ovariectomized (OVX)
    rats has been shown to be prevented by diets containing natto supplemented with MK-7, and prolonged intake of dietary natto, including MK-7, has further preventive effects.

    • Janet says

      Hi – Endocrinologist Dr. Diana Schwarzbein says this on page 50-51 of her book The Schwarzbein Principle: Because the action of the thyroid hormones (there are 10 of them) is to utilize proteins, to protect against malnourishment, your body will decrease thyroid production when you are not eating enough food (chronic dieting) or are eating an imbalanced diet (too much sugar, carbs, caffeine, etc). Also, when your body is functioning properly, it converts the thyroid hormone T4 into T3, which tells the cells what to do. If your body perceives it is under stress from actual stress, an imbalanced diet, etc, the T4 is converted into “reverse T3” & the symptoms are: overweight, cold, tired, achy, constipated, hair loss, depression (page 44, The Schwarzbein Principle II). The only way to heal this is to modify your diet to make it more balanced with the proper amounts of protein, healthy fats, non-starchy vegetables (preferably organic) and gluten-free carbs, get enough sleep & heal your gut if you have “leaky gut”. Please understand that your body converts sugar, carbs, caffeine, etc into FAT – specifically, triglycerides, “bad” cholesterol, glycogen & energy for immediate use.

  13. coco says

    i have problems with a big bone spur in my right foot, tiny ones in my shoulder and spine. i’m 68 i got today the k-2 mk-7 and apple cider vinegar in capsules to dissolve the bone spurs and to re-direct the calcium to the right places

    • Annie says

      Buy K2 MK-4. It has a short shelve life. Take it with a little healthy fat, about 2 times aday..
      That will take the calcium to your bones and not your arteries.

      For bone spurs, buy the vitamin, “Acid A Cal” Amazon sells it and it work..Its only about 10.00.

      For Obesity, Read, “Wheat Belly” Dr. William Daves..

      Don’t eat , Processed foods, wheat except Einkorn, no fast foods, No Sugar, NO Diet soda, or any soda.
      Walk your ass off..

      Good Luck..

    • Julielu says

      Coco, how has the supplement program been working? Did you continue with the K2 _Mk-7 natural extract with the cider vinegar? Have the bone spurs reduced or become less painful?

  14. Joan says

    I have hyperparathyroidism and high calcium levels, I have had this condition for years and will have a parathyroidectomy soon. I have a lot of calcium deposits, some in arteries. I am having difficulty getting K2 from dietary sources. Would the Green Pastures buttermilk/cod liver oil be a good supplement for me, or would you have another recommendation or recommendations for me?

      • says

        However, while very few people have a K1 deficiency or we would bleed to death, for K2, the MK-7 version is, by far, the most important and effective as it lasts in the body for about 3 days, where MK-4 lasts for a few hours and is required in doses about a thousand times higher than MK-7.

        You have to take MK-4 three times a day to get much effect and then at doses of 15 mg three times a day.

        Where published dose-comparison data show that 180 mcg (one-thousandth of a mg) of MK-7 is highly effective in directing calcium away from artery walls and can be taken once a day.

        You’ll get plenty of K1, which has little to no effect on protecting arteries, from green vegies.

        You get K4 from meat fat.

        It’s the MK-7 that Americans are grossly deficient in, because 95% of our dairy fats is grain-fed, where pasture-raised, grass-fed dairy fats, like they have in France, Holland and many other countries has as much as 50 times more MK-7.

        Their cheeses and butters give them lots of MK-7, which is one reason that they have much lower cardiovascular disease than Americans.

    • Paula says

      Hi Joan. In addition to K2, also look into boron defficiency, as boron balances and fuels the parathyroid glands. Boron is in most organic vegetables and fruit, but depending on where you are in the world the soils can be defficient so we aren’t getting what we need. Boron can be the cause of arthritis, heart and bone diseases as well as parathyroid diseases. You can take it in capsule form at 3mg daily or directly and more inexpensively from small doses of pure borax, though you’d have to research that as I’m not sure how much you would have to take.

    • Janet says

      Hi, The doctors thought I had a hyperparathyroid problem a few years back, but I was just consuming too much calcium. Dr. Dwight Lundell says overconsumption of simple, highly-processed carbs like sugar & grains causes our blood sugar level to be too high, which is like rubbing a stiff brush repeatedly over soft skin (the inside of our arteries) & the “scab” that develops to protect the inflammed artery walls is plaque. Which is comprised of 50% calcium, 47% fibrin & 3% “bad” cholesterol. Endocrinologist Dr. Joe Prendergast in Palo Alto, CA has been successful reducing plaque with L-arginine & vitamin D3 – they both help regulate inflammation & the vitamin D3 helps manage calcium. By the way, calcium does absolutely NOTHING to help prevent or treat osteoporosis. The nutrients that help with that are vitamin D3, vitamin K & magnesium. Look for the Spring Edition 2012 newsletter from in Redwood City.

  15. Marion says


    I’m osteoporosis since a while and it’s not improving.
    Can you help me please ?
    I take some Calcit Vit D since a few years and Oestrogel wiht Utrogestan since a year.
    I had Aclasta in 2012 when I broke my femur a little bit.
    Sorry for my language, I’m French.

    Thank you in advance for your help.

    • Paula says

      Don’t forget boron. Calcium and magnesium don’t get regulated and absorbed properly without it. Our soils can be very defficient.

    • Annie says

      Take K2-Mk-4. It takes the calcium to your Bones and Not your Arteries..
      D3 iu 5000 , but get it check. Your might be low, or 5000 is too high!!
      Do not eat processed foods, No smoking, no sugar, no wheat, no fast foods, No soda, and too much coffee can rob your bones of calcium…there is allot more for osteo also..Drugs are not good for Osteo..

    • Annie says

      Take K2-Mk-4. It takes the calcium to your Bones and Not your Arteries..
      D3 iu 5000 , but get it check. Your might be low, or 5000 is too high!!
      Do not eat processed foods,

  16. Mike says

    I understand this article is from 2009, but these is some interesting research that has come out recently that may help people.

    The link is an article about converting k1 into k2. Consider this quote “…modern humans are deficient in K2 because they do not eat large quantities of vitamin K1 containing foods. If we look at Paleolithic humans, they probably got high amount of vitamin K2 from eating large quantities of kale and spinach-like foods, very high in K1, which then supplied their tissues with all the vitamin K2 they needed.”

    Just some food for thought!

    • Michael Mooney says

      It is highly unlikely that the average American gets enough K1 to convert to K2 (MK-4), which, like K1 has a very short half life of 1 – 1 1/2 hours. While there is recycling, K1 can’t be counted on to express K2 activity to a great extent, as K1 has been consistently shown to not improve cardiovascular risk factors the way that K2 (MK-7) does.

      • Annie says

        K2-mk-7 can cause a fast heart beat, and keep you awake at night..It also does not need to be taken everyday..

        K2 MK-4 has a short shelve life in the body. About 3 to 4 hours. It needs to be taken about twice aday, with a little healthy fat.
        Take the calcium to your bones and Not your arteries ..

        Aged hard cheese . Like Gouda cheese has K2 Mk-4..

        We get k1 from Greens…

        • Sheena says

          And not just this confusion of vitamin k2, m4 and m7. People are not getting it that vitamin k2 m7 is soy based. Certainly not for people with soy allergies. So take vitamin k2 m4 twice a day. Goes directly to the bones, and clean out your arteries.

          • Sheena says

            I mean mk-4 and mk-7. Even if vitamin k2 mk-7 is fermented soy and non-gmo, not all of it is processed or removed.

    • Julielu says

      It is reported by other researchers that the Vit k2 from our own gut bacteria is little absorbed since it’s bound to the bacteria bodies that produce it and leaves with our faeces…

  17. Sara Evans says

    Hi Chris, my son is 4 and has been fed a 90% paleo diet all his life. Recently to my shock, we were told he has enamel decay on 6 teeth. Given his low sugar diet, I am at a loss of what to do to prevent further issues. I was looking in Vitamin K2, what do you think? Any thoughts would be appreciated. Thanks.

    • Mark Spence says

      In the second hour of the Robert Scott Bell radio program on October 10, 2014 there is a wonderful informative interview with Dr. Nicholas Gonzales about teeth regeneration. Thank heaven this info is available with podcasting.

      • says

        I live in London, uk. aged 67, female. A severe bone loss in upper (and lower) jaw has ‘suddenly’ been noticed by new dentist. really shocking.
        Regime of cleaning mostly excellent. Diet mostly good: kale, spinach, sprouted shoots, butter, olive oil, coconut cream, all greens, fish, cod-liver oil, no soy, no sugar or wheat (except spelt, gram, rye); fruit and salads. apple cider vinegar fairly often. with teaspoon of raw honey.
        very little meat. Will try liver. I ate part of both placentas (first cooked, then raw, second time!) with both home births, and felt immediately stronger, my milk came in fast.
        No drugs, no vaccines, was brought up on wholely home-grown veg and salads. Local fish, meat or poultry, grass-fed, and this has kept me really healthy.
        Slight palpitations these days, and some joint pains, after bike car-hit-and-run.

        Addiction: breakfast teas, roibosh and herbal infusions from garden (not coffee, much) but indulge in occasional org coco-hemp bits with raw yogurt at night (may be why!) And a case of shock a few months back… New dentist asked “do you smoke?” No. I stopped my one or two rollups a week, ages back. Two kids, four pregnancies.
        Loss of enamel, too.

    • Rpt says

      Teeth health is a function of vitamin D, vitamin K, and magnesium via the saliva. It may be that he doesn’t have tooth decay because of sugar, but that he has tooth decay because of insufficient minerals in his diet. He should be taking all of the above, via diet and perhaps supplements to ensure teeth health.

    • Beth says

      I would be investigating for coeliac disease – there is a known correlation between that and tooth enamel defects. Both my daughters have this issue as a result of coeliac disease – and they have a super healthy diet i.e. not much processed sugar at all. I was horrified…

      • Julielu says

        see Vit K2.
        ps – i query a link between the ‘coeliac gene’ and K2 since auto immune diseases often associate with abnormal hardening of soft tissue and softening of bone tissue

  18. says

    Very interesting article! Regarding K2 content in meat, how significant is the animal’s diet to the K2 content of the meat? In other words, is ground beef sourced from cattle raised on a conventional feed diet (little to no green grass) high in K2?

    Also, why is ground beef high in it, as opposed to other cuts of beef?

    I’m looking for non-dairy food sources of K2 since my daughter is allergic to dairy products.

    Thank you!

    • Peggy says

      Astaire, if a cow stops eating grass for one week, its meat nor milk will not have much vitamin K2 left. Vitamin K2 is fairly short-lived.
      The fermentation process can increase the vitamin K2 content.
      Vitamin K2 is fat soluble and would be higher in fatty meats; I am not sure what ends up in ground beef.
      If your daughter cares to eat natto, about 10 gm of natto has enough vitamin K2 to lasts several days
      Or she could take a supplement derived from soy such as the Twin Lab Dots vitamin D3 + K2 Vitamin
      Take care, PLM

      • says

        Don’t feed your Daughter or any child, person SOY..
        Soy is Gmo, and if its not, it is not food fit for a human.

        Soy is a Hormone to fatten up Cows, Pigs, Chickens etc..
        Its a cheap food..It was really not meant for humans..
        Even in Organic chicken food, the second ingr. is Soy.
        Organic soy is not healthy.

        That said, some of you are going to say, but Asians eat it and there healthy.
        Asian eat Natto, and use it as a dipping sauce..A condiment..

        You might want to ask your Dentist, or a Homeopathic Dr. what is the right way to go for your Daughter.
        SOY is NOT.

        Many people say there allergic to eggs, we are not finding out, its not the Eggs, it’s the Soy the chickens are being Feed..
        Once you find and eat soy free eggs, the allergy to eggs is gone.

        Good Luck, I would be concerned also.

        • Andrew says

          Natto is fermented soy, so it doesn’t have the phytoestrogen effect on humans that unfermented soy does. One can’t assume that natto comes from GMO soy, and even if it did the compounds of soy beans are converted into natto kinase (K2) during the fermentation process. Most producers of natto (K2) use a process to isolate the active compound when they produce a K2(menoquinone) supplement. If you want a couple of reputable supplement producers whose manufacturing process has the highest standards, I would be glad to supply the list.

        • David I says

          Wow, I’ve seldom seen so much misinformation packed into such a shot post.

          First of all, natto is not a “dipping sauce.” Natto is incredibly sticky, and using it for dipping would create a hilarious mess.

          Second, NONE of the soy used in Japan for human consumption is every GMO; it is against the law.

          Third, natto is one of tiniest uses of soy in the Asian diet. The big ones are tofu and tempeh. But those are consumed in rather substantial amounts, and many many different forms.

          Fourth, if you have ever eaten natto, then you would know that it is consumed in such small amounts that the phytoestrogen content would be consider negligible.

          Fifth, although opinions are divided on the topic, many researchers believe it is the phytoestrogens that make soy an inhibitor of breast and prostate cancer.

          People in Japan who eat natto frequently have far lower levels of osteoporosis and cardiovascular disease. It is a traditional food that has been used for about a thousand years and is widely considered to be one of the healthiest foods in Japan.

          But I guess you know better, right?

  19. Joe cave says

    See this open access article. The abstract follows below
    1 Department of Biomedical Sciences, University of Illinois, Rockford, IL 61107, USA
    2Department of Pathology, University of Illinois at Chicago, Chicago, IL 60612, USA
    Correspondence should be addressed to Munirathinam Gnanasekar; [email protected]
    Received 13 March 2013; Accepted 30 May 2013
    Academic Editor: Richard Pietras
    Copyright © 2013 Abhilash Samykutty et al. This is an open access article distributed under the Creative Commons Attribution
    License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
    In recent years, several studies have shown that vitamin k2 (VK2) has anticancer activity in a variety of cancer cells. The antitumor effects of VK2 in prostate cancer are currently not known. In the present study, we sought to characterize the anticancer potential of VK2 in both androgen-dependent and independent prostate cancer cells. Our investigations show that VK2 is able to suppress viability of androgen-dependent and androgen-independent prostate cancer cells viacaspase-3 and -8 dependent apoptosis. We also show that VK2 treatment reduces androgen receptor expression and PSA secretion in androgen-dependent prostate cancer cells. Our results also implicate VK2 as a potential anti-inflammatory agent, as several inflammatory genes are downregulated in prostate cancer cells following treatment with VK2. Additionally, AKT and NF-kB levels in prostate cancer cells are reduced significantly when treated with VK2. These findings correlated with the results of the Boyden chamber and angiogenesis assay, as VK2 treatment reduced cell migration and angiogenesis potential of prostate cancer cells. Finally, in a nude mice model, VK2 administration resulted in significant inhibition of both androgen-dependent and androgen-independent tumor growth. Overall,our results suggest that VK2 may be a potential therapeutic agent in the treatment of prostate cancer.

  20. Anthony Yam says

    Dear Chris,

    I heard that warfarin cuases stenosis of the coronaries and Vitamin K may reverse the process and at the same time reverse the coronaries and all blood vessel calcification.
    How correct is this and how long it may tame? Please advise the approximate amounts of K1 or K2, Vitamins A and D, etc.

    Thanks very much.

    • Matt says

      why would you want to take Vit K1 if you are on warfarin? Its purpose is stop abnormal clotting in the human body by acting as a Vit K1 atagonist, so taking additional K1 will only increase the chance of forming a potentially lethal clot.

      Why not change to an alternative to warfarin if you can, though products such as dabigatran cost a lot more.

      • says

        Aspirin is also a blood-thinner and non-toxic… naturally taken from trees. Small doses throughout the year… could help. But diet and exercise and meditation work best. And a loving attitude of gratitude to this wonderful earth… seeing her as our paradise, nurturing and nourishing us despite our worst efforts… without cease. We hold a vision of a whole and healthy and joyfully challenging planet.
        No more cattle pollution… worse than all the cars, factories, aircraft.
        Restored (re-stored) to her rightful balance. We are the only animals to destroy and pollute our nest.
        Nature Rights – be the Voice for Nature’s forests, waters, creatures everywhere.
        And who knows why America began chem-trails?

    • rpt says

      The current recommendations are to take a base level of vitamin K to help stabilize the impact of blood thinners like Warfarin.

      See below, from a discussion by Joanna Becker
      Although it may seem counter-intuitive, increasing evidence has shown that the common anti-green vegetable lecture imparted to all patients starting warfarin may actually be doing more harm than good. Such advice may be setting up patients for a widely variable and difficult to manage INR. Low-dose vitamin K supplementation may actually improvethe stability of anticoagulation therapy.

      What is therapeutic stability and what factors influence it?
      A patient’s ability to achieve a stable INR on anticoagulation with warfarin is essential for protection against thromboembolic and hemorrhagic events. Stability is generally quantified by the standard deviation (SD) of measured INR over a certain period of time. In one study, the median standard deviation of INR in a single clinic population was 0.3 over 6 months. The researchers classified patients as unstable if they had a SD >0.5 and at least 3 changes in warfarin dose over the prior 6 months. Of note, patients with instability attributable to factors such as poor adherence to therapy, other medications, comorbidities, or excess alcohol consumption were excluded.[2] In addition to these controllable factors, stability depends on a number of uncontrollable factors including age and CYP2C9 and VKORC1 polymorphisms. Although genotype can aid in determining anticoagulation initiation doses by being plugged into dose-optimizing algorithms, genotype is not a factor in the ability to maintain stability once it is achieved.[6] On the other hand, vitamin K intake still plays an independent role and thus represents a controllable factor that we can manipulate to improve stability.

      What is the relationship between low dietary vitamin K and INR stability?
      In a 2010 review in the British Journal of Clinical Pharmacology, the authors contend that, “Older recommendations for diets low in vitamin K as appropriate for warfarin-treated patients should now be considered outdated.”[3] Their conclusion is based on research such as the 2004 study by Kurnik and colleagues, which found that vitamin K-depleted patients had significantly greater fluctuation in INR when given vitamin K supplementation when compared with non-depleted patients.[4] In other words, low vitamin K levels cause a patient’s warfarin requirement to vary with even minor changes in vitamin K intake. In 2005, Sconce and colleagues went one step further and demonstrated that patients with low dietary intake of vitamin K were more likely to have unstable control of anticoagulation.[5] These results were then replicated in a 2010 study by Kim and colleagues.[6] When taken together, these studies conclude that patients with low vitamin K intake are more sensitive to minor changes in vitamin K intake and thus more likely to have therapeutic instability.
      Does vitamin K supplementation improve stability?
      Based on the above data, it can be hypothesized that vitamin K supplementation is particularly useful in achieving therapeutic stability in patients with low vitamin K intake. In such patients, daily fluctuations in vitamin K intake lead to significant and proportional changes in INR that can be avoided by oral supplementation.[3] A 2007 study by Sconce and colleagues put this hypothesis to the test in the first randomized, blinded, placebo-controlled trial investigating the effects of vitamin K supplementation in 70 unstable patients over 6 months. When patients with unstable anticoagulation were given 150 mcg of vitamin K supplementation per day, they spent a greater amount of time within target INR range and had decreased daily variability in INR when compared with placebo.[2] These findings were consistent with other literature including a 2005 trial by Reese and colleagues[7] as well as a 2007 study by Rombouts and colleagues[8] using phenprocoumon (a longer-acting vitamin K antagonist) as the anticoagulation agent. Finally, a recent 2010 study by Gebuis and colleagues looked at patients taking phenprocoumon or acenocoumarol and compared the effects of placebo with 100-, 150-, or 200-mcg vitamin K supplementation. Although the supplementation provided improved stability, there was little difference between the doses.[9] Ultimately, low-dose vitamin K supplementation, regardless of dose, was shown to improve therapeutic stability in patients with unstable anticoagulation with warfarin or its derivatives.
      What should we tell our patients? When and in whom should we start supplementation?
      It is clear from the research outlined here that cutting out vitamin K is not the answer for achieving stable anticoagulation. Instead, inform your patients of the vitamin-K rich foods and advise them to maintain a steady dietary pattern. If they have any planned dietary changes or adjustments in multivitamin use, these should be reported. According to the 2008 clinical practice guidelines published in Chest by Ansell and colleagues: “For patients receiving long-term warfarin therapy with a variable INR response not attributable to any of the usual known causes for instability, we suggest a trial of daily low-dose oral vitamin K (100 to 200 mcg), with close monitoring of the INR and warfarin dose adjustment to counter an initial lowering of the INR in response to vitamin K (Grade 2B).”[10]
      In summary, patients no longer have an excuse to avoid leafy green vegetables, missing out on all the other nutrients they harbor as well as vitamin K’s role in slowing vascular calcification[10]. Vitamin K will help rather than hinder the chances of achieving long-term stable anticoagulation. If a patient has a consistent diet and all other causes of instability have been eliminated, try vitamin K supplementation.

  21. Anthony Yam says

    I have 3 coronaries heavily blocked, main one close to 90%, the other 2 65% , about to go through stenting on the main one. CT shows sheows calcification index of 4000 against a normal 400. What would you recommend using readily available food or supplements containing K2 or other nutrients. What amount should be taken daily? How long and how good the results may be?

    Thank you.

    • Peggy says

      If you have a chance, please read Vitamin K2 and the Calcium Paradox by Kate Rheaume-Bleue. This was recommended by several other posts, and I really liked this book. It took many months (9?), but she reports significant improvement with moving calcium out of the calcified arterial plaque into bones (where it belongs) when BOTH vitamin D3 and vitamin K2 were taken. She recommends the MK7 form derived from natto; a small amount lasts several days. One supplement with MK7 is the TwinLab Dots with D3K2 taken sublingually. It only has 1,000IU D3, so you would ideally add more D3 (probably 5,000 IU daily or enough to get your levels up to 60-80ng/ml of the 25 OHvitaminD). I know that the Weston A Price Foundation eventually determined that the fat soluble Factor X was vitamin K2 (derived from fermented grass-fed dairy fat) in the MK4 form, but the MK4 vitamin K2 takes a much larger dose of 45MG 3x/day rather than about 100MCG (not a typo!) of the MK7 form derived from natto taken daily or every other day. I hope you are also taking magnesium, fish oil and CoQ10.
      Eating natto would be the most helpful since natto contains both nattokinase (which dissolves blood clots) and vitamin K2 (which helps move calcium into bones from arteries and tissues), Keep in mind that vitamin K2 will not work without plenty of vitamin D, another fat soluble vitamin.
      Vitamin K2 also looks good for fighting cancer…

      • micki says

        Twin labs has changed from MK-7 to MK-4.
        FOLKS…eat the foods!
        Eat cheeses, yogurt, kefir, sauerkraut, offal, bone broth, mollusks, and plenty of greens.

  22. says

    High quality K2 is very expensive but so worth it. A gramme of pure K2 costs around $1000, so a daily dose of 100 mcgs costs 10 cents and that is a wholesale price. Because weighing microgrammes ( a millionth of a gramme) is so difficult the K2 is sold with excipients and in kilo lots with a rating of ppm. We buy 2000ppm in kilo lots for around $2,000 a kilo and so receive 2 grammes when you do the maths. Essential to take with D3 for calcium bone health. It is fat soluble so purists recommend taking it with fat. We add piperine with our MCHC calcium capsules as well as D3 and K2. The piperine aids in the absorption of all three. MoJoe

  23. Mike says

    99% of soy if GMO, so if it doesn’t say “non-GMO” or something to that extent, believe that it has GMO’s in it.

    Angie (above) –
    Amazing, but Bragg’s Aminos, while they are non-GMO, they are not fermented soy. Chris is right that it’s a processed soy product. Overall, the product is not good for most people.

    • David I says

      That 99% number is baloney. It isn’t 99% even in the US, and the US has the highest percentage of GMO soy.

      In Japan, all domestically grown soy is non-GMO. They import soybeans from elsewhere (mostly Brazil and Canada), for a variety of purposes, but not for direct human consumption. In addition, most natto is made from a special “natto” breed of soybean.

      Almost all natto for sale in the US is from Japan. But in any case, the amount of natto that you need to eat–a single serving–to get a megadose is extremely small. A serving comes in an individual container that holds 40-50 grams, about an ounce-and-a-half. That’s about two tablespoons of natto.

      Chances are very very low that any natto you buy is GMO.

      And, at two tablespoons, I think that people who are flipping out about phytoestrogens and goiterogens have completely lost their sense of proportion. They’ve been eating natto in Japan for about a thousand years now, and in their culture it is associated with nothing but good health.

  24. says

    Vitamin K2 is not just one thing. There are various types in the “MK” family. MK-4 is the one that WAPF talks about as the “X-factor”. Natto is high in MK-7, not MK-4. This 2014 article goes into great detail…

    Recent trends in the metabolism and cell biology of vitamin K with special reference to vitamin K cycling and MK-4 biosynthesis
    Martin J. Shearer1,* and Paul Newman†

    March 2014 The Journal of Lipid Research,

    • David I says

      You seem to be claiming that WAPF somehow endorses MK4 and rejects MK7. Just to clear things up, here’s what Chris Masterjohn says in his article “On the Trail of the Elusive X-Factor” at WAPF:

      “Fermented foods such as sauerkraut, cheese, and natto, a soy dish popular in Eastern Japan, contain substantial amounts of vitamin K2. Natto, in fact, contains the highest amount of any food measured; nearly all of it is present as MK-7.26 MK-7 is highly effective: one recent study showed that it increased the percentage of activated osteocalcin in humans three times more powerfully than did vitamin K1.32 There are no studies available, however, comparing the efficacy of MK-7 to that of the MK-4 found in animal products. MK-9, and presumably MK-7, stays in the blood for a longer period of time than does MK-4, but this appears to be because tissues take up MK-4 much more rapidly.30 Whether the rapid uptake of MK-4 or the longer time spent in the blood by bacterial menaquinones have particular benefits or drawbacks is unclear. Future research will have to clarify whether the vitamin K2 synthesized by animal tissues and by bacteria are interchangeable, whether one is superior to the other, or whether each presents its own unique value to our health.

      Supplementing with Vitamin K2

      The best sources of vitamin K2 are fermented foods and grass-fed animal fats. These foods contain a wide array of nutrients that may act synergistically with vitamin K2 in ways we do not yet understand. Price ‘s vitamin-rich butter and butter oil concentrate provided not only vitamin K2 but also vitamin E, vitamin A, vitamin D, conjugated linoleic acid (CLA) and other nutrients. Nevertheless, some people may wish to supplement with vitamin K2 if they do not have access to high-quality food, wish to use a higher dose to treat a health condition, or want extra insurance.

      Two forms of vitamin K2 supplements are commercially available: menaquinone-4 (MK-4), also called menatetrenone, and menaquinone-7 (MK-7). MK-4 is a synthetic product that is believed to be chemically and physiologically identical to the vitamin K2 found in animal fats. This form has been used in most of the animal experiments and in the Japanese osteoporosis studies. Although synthetic, it is effective, and there is no known toxicity. MK-7 is a natural extract of natto, a fermented soy food popular in Eastern Japan. MK-4 is much less expensive than MK-7, but no studies have yet compared the efficacy of these two forms.”

  25. Tess says

    I have been taking 5,000-10,000 D3 per day – my doctor said D was low. I’m interested in taking K2 – how should I take it – I believe Natto is soy – Sloan Kettering told me to stay away from Soy – after having breast cancer. Should I add magnesium supplement? Thank you.

  26. mark says

    hello everyone. I just want to ask if vitamin k2 helps with blood clotting? because i eat natto every day which provides ample k2 but i read that k1 is required for blood clotting and that the best sources of this vitamin are leafy green vegetables, but i didn’t think these were a good paleo food. I don’t eat leafy greens and i have also read that absorption of vitamin k1 from leafy greens is as low as 10%. So if this is the case i wondered if adequate k2 will help with regards to blood clotting at all? Thanks for any help/thoughts,

    • Matt says

      nope, K1 is the version of Vit K that is used by the liver to produce the various blood clotting factors. K2 has no impact on blood clotting.

      I’m a long term warfarin “addict” and I have to avoid K1 but can ingest K2.

  27. James Bembridge says

    Hi Chris, I ordered MK4 supplement from Relentless Improvement, each capsule contains 15 mg is this too much mk4 to take daily?

    I read a study that showed mk4 increases testosterone in rats, I wonder if mk4 increases testosterone then your body may produce less naturally, or when you stop taking mk4 similar to how steroids effect testosterone production?


  28. Aussie says

    Hi Chris,
    Thanks for very interesting article, dad had three heart bypass twelve years ago, stopped taking statins couple of months ago and I am interested in the possible reversing of calcification in arteries. Live in Australia and would like to know if by eating Brie an Gouda cheese would provide enough vit k2 and how much cheese should be taken daily, also does blue cheese also contain vit K2? Thanx

  29. says


    I know that good sources of K2 is hard cheese and especially GUDA cheese, because of the kind of the microorganisms that make it. But I read that yogurt hasn’t any.

    I am not convinced that KEFIR has K2 and you don’t give us any proof. Is there any web page showing that?

  30. Kate says

    Do you have any advice on K2 for paediatric dosing? I’m looking to supplement my 3 yr old with D3 but I’m reluctant without also ensuring that she has a K2 supplement and magnesium. I’m finding it very difficult to find information on a sensible K2 dosage – or whether it’s best to do these things off age or weight. Based on weight – 30lbs – I’m considering up to 1000iu D3 and 100mg magnesium citrate, I’m reluctant to proceed without the vitamin K2, but she could really use the boost to her immune system. Any help gratefully received!

  31. Jared says

    While obviously the best source of vitamin K2 (Mk-4 and Mk-7) is from whole foods. There is a supplement I take that contains both types in it called the Daily Multi Nutrient. I think it’s a good option, especially considering some of the preliminary research behind supplemental K2.

  32. getwell says

    Does anyone know of research that would contraindicate supplementing with large does of K1 (1000mcg)? Some of the convenient supplements that contain mk4 & mk7 also contain K1. I am wondering if it has a negative clotting effect (too much clotting factor).

    • rpt says

      You can’t take too much vitamin K. Per the FDA there is no upper limit. And too much vitamin K will not interfere with your clotting factor. A deficiency of vitamin K can interfere with clotting, but high levels are not a problem.

  33. Dan says

    What is the best natto starter for making high quality natto?

    I understand some companies sell low quality starter like cultures for health and body ecology for example both sell milk kefir grains that stop repopulating where as Kefir Lady and other providers sell high quality kefir grains that last indefinitely and just keep repopulating as long as their fed, so is there natto starters that last indefinitely?

  34. says

    Hi Mary Jo,
    I hope you see this message!

    I’m glad to hear Your out of the Osteoporosis range. Yay.

    While I’m eating I take about 5 to 6 drops of K2 MK-4 twice aday..You need to take a little healthy Fat with it..Organic coconut oil is a good choice, but healthy fat could be in the food your eating when you take it.
    Not sure how many drops your taking, but you do not have to over do Mk-4..I know of some people that just take a couple to 3 drops,and there teeth feel smoother.
    Do your teeth feel Smoother? as most peoples do when they take MK-4. .

    D3 works better without fat.

    There is a great group of people on that have Osteo, and there is some Awesome information there..Just hunt around on that website about k2 MK-4.

    • Mary Jo says

      Hi Annie,
      Thanks for the info. I am actually taking one pill that is 15000 mcg dosage. I take it in the morning with my other vitamins. I have not noticed anything with my teeth. I am concerned that it is too much.

  35. Adrian says

    Dr.Mercola advises against the intake of vitamin K2 when one is on blood thinners. Does that also hold for clopidogrel (sold in Australia under the name Plavix)?

  36. says

    I would like to answer Mary Jo’s question about K2-MK4, but cannot find her post!

    Sorry to say this, but this is a mess lol.. But what type of order do you have these in?
    As there not by Date etc.!!!

    Take Care,

    • Mary Jo says

      Hi Annie,
      I understand that you tried to reply to my post regarding my dosage of 15,000 of MK-4 but were unable to.
      In the meantime I had a follow up dexascan and the results show that I improved from osteoporosis to osteopenia. I am not sure if the K2 was the factor or not. My doctor still insists that this dosage is way too high.
      I would still value your input.
      Thank you

      • says

        Mary Jo,
        Glad to hear your Dexa came out so good.

        Are you really taking, 15,000 mg of K2- MK-4? Way too HIGH..
        I think you mean, 5 mg. or 15mg ??

  37. Ben Tidearsch says

    You’ve listed salami as a food rich in K2. It would’ve been more informative if you’d mentioned that salami – and a lot of processed meats – also contains high levels of sodium chloride, sodium nitrate, sodium nitrite and sodium erythorbate.

    Processed meats can contribute to pancreatic cancer. My father manufactured processed meats in his business and died of pancreatic cancer. This type of cancer doesn’t show up until it’s too late, with an 85% mortality rate, and you generally only get “6 weeks” after diagnosis.

    I’ll look for K2 in alternate sources. Thanks for the article, very informative, other than this omission.

  38. Marc says

    Geez!!! stop worrying about your prostate!!!
    just drink water, eat LOTS and LOTS of fruit,, and LOTS and LOTS of green leaf vegetables and herbs (including lettuce).
    Avoid junk, bread, candy, soda, pasta and other junk things and you wont need to worry about anything!!!
    Cheese is shocking for you!!! but in small amounts its not a problem if you are eating fruit and vegetables and water.
    if you can ‘tip’ the balance on your scales of healthy Vs junk food, then you wont need to worry!!!
    also: you answered your own question in this article!! you said that cattle that eat alfalfa and wheatgrass will have more K2 because of the vitamin K in what they are eating!!! so??
    go ahead and eat wheatgrass and alfalfa!!!
    also: KALE and basil and a whole host of other green leaf plants are full of K2 !!!
    not as much as Natto,, but really, so what, Lol !!
    just eat healthy and you wont need to worry about yours or anyones prostate 😉

    • says

      “Cheese is shocking for you!!!”… and where did you get this idea? Care to post some evidence to back up this OPINION? Study results?

      • John says

        About “cheese is shocking for you…”
        You could try to read the book “The China Study”
        The fats and proteins in dairy are like those in flesh but in a liquid and more digestible manner. This is good and bad but after being converted into cheese, it becomes more difficult to digest.
        Eating food that taxes the digestion system is not wise… on the other hand, eating fresh fruit and vegetables with their enzymes intact can be processed and assimilated by the body much easier…

  39. Dianne Miller says

    I was wondering about the use of K2 if you are taking nattokinase for a blood thinner. My husband has A-Flutter and is on Diltiazem, a calcium channel blocker. He didn’t want to go on Warfarin. He is taking a few supplements and I’ve read that you need a good amount of K2 if you are supplementing others such as magnesium, D3, etc. But wouldn’t the K2 be counter productive if you are trying to keep the blood thin? When he was on Warfarin he was told he couldn’t eat the veggies and oils high in Vit. K. Thanks for any input.

    • Nevada_Smith says

      Read the other comments especially by Chris. This has already been answered more than a few times.

  40. Annie says

    When you refer to K2, your not saying which K2!!

    There is K2 MK-4, and there is K2 MK-7..
    There both a bit different..
    Just want to mention , that we get plenty of K1, by just eating Greens..
    K1 has been to known to give a few people Leg Cramps, but that will not happen with the K2’s.

    K2- Mk-4 takes the calcium to your Bones and Not Your Arteries -Soft tissue .
    K2 MK4 has a short shelve life in the body. about 4 hours.
    You need to take it about 3 times a day while eating, and with some healthy fat. Olive oil, Avocado’s, Organic Coconut oil, Organic pastured Butter etc. . Not processed oils, or fats.
    When talking about meat. Its Organic Pasture meat.
    You also need to take D3 once a day with it also.Some Drs. recommend 5000iu D3 aday. That said, get it checked by your Dr. to know how low or high your D3 is.

    K2 Mk-7 has a longer shelve life in the body.
    About 3 days.
    Some people that take K2 Mk-7 will get heart palpitations,and have a problem falling asleep.
    If you do take it. Start off SLOW, and do not take it before bed.

    There are cheese’s that have k2 MK-4.
    But not all hard cheese have it etc.…
    Aged Gouda is one of them to take, but you have to eat allot.
    Natta has both types, but most people have a hard time eating it, as it slimy for some, and stinky.
    You can find at most Asian markets.

    Amazon sells K2 MK-4 which is made by Throne. It is pricey, but lasts a long time.

    I do NOT have anything to do with Amazon or Thorne vitamins..

    I hope this all makes some sense!!
    There are some good books out there about K2 etc..
    One is:
    “Vitamin K2 and the Calcium Paradox: How a Little-Known Vitamin Could Save Your Life” By Kate Rheaume-Bleue.

    I have nothing to do with this book.
    I have Osteoporosis, and need to be Very Pro-Active about my Bones, Health..

    • mark says

      Hi Annie, thanks for your reply. I still have a problem regarding vitamin K1 and leafy greens as i still don’t see how our ancestors could have accessed the K1 without cooking the greens because of the cellulose problem? and where did our ancestors get leafy greens during ice ages which lasted for thousands of years at a time? This got me thinking as to whether or not parts of the animal we no longer find palatable may have been a good source? considering the K vitamins are fat soluble i can’t see how leafy green vegetables could be the best source? I have also read all gouda cheese is a good source of K1 because of the bacteria used in the fermentation process? The internet seems to offer conflicting advice on the subject! I do not eat leafy greens and my blood clots fine so maybe i am worrying about nothing, but i am interested in the K vitamins after reading about K2 and the ‘green leafy veg best source’ bit got me thinking you know?
      Thanks again though,

      • says

        Hi Mark,

        I have no idea how our ancestors ate Greens!
        Are you talking about the Paleo Diet?

        I do know when I grow my Organic greens , I get Leg cramps from it, when I eat a big salad.
        This also just made me wonder how long our Organic Greens for salad sit on the shelves in the Market, or by the time we buy our Market greens, how long after there picked, and on the shelves to we get to buy it!
        (I live in California)

        Someone , on another website about Osteoporosis described in chemical terms why leg cramps happen from Greens ..Right now I would have to do allot of searching to find it..I do not have the time.

        Take Care,

    • Mary Jo says

      Hi Annie,
      Thanks for all of the information in a very easy to understand way. I too have osteoporosis and have been trying to be proactive with my care. I started taking K2 Menatetrenone which I believe is MK4 (15,000 mcg). When my doctor saw the dosage she immediately suggested I cut back for fear of blood clots. In your research have you found what dosage is safe?

  41. mark cheshire says

    Hello Mr. Kresser.. I have been reading a lot recently about vitamin K, especially K1 and K2 and have read your articles on the subject. I am eating gouda cheese for my K2 requirements, but i am a little confused regarding vitamin K1. It seems the best sources are leafy green vegetables? Now i thought humans could not digest cellulose, so how would we have obtained vitamin K1 from raw leafy green veg without cooking it to break the cellulose down? We did not evolve eating cooked foods, and throughout ice ages there were very few green leafy vegetables to be eaten and the Inuit don’t consume these foods regularly either, so i wonder if human beings can synthesize K1 in the body naturally? I just don’t see how we could have obtained it through raw green veg during evolution and ice ages?
    Thanks for any input,

  42. ninad says

    You talked about fermented food as good source of k2. Can you please talk about indian fermented foods like idali dosa curd etc?

  43. Gary says

    I’m taking 4 mg warfarin qd for chronic afib. I try to avoid food items with vit K but is it ok to take a supplement that contains vit K2?

  44. Tricia Agostini says

    A Nattokinase product – Nattokinase NSK-SD – (emanating from the Japanese Scientific Laboraory) states it has removed K2 from this Natto extract to accommodate people who are on Warfarin: they say while natto dissolves Fibrin in the blood & so thins it & warfarin also thins the blood – I don’t know by what mechanism, K2 does the opposite & is a clotting agent – hence they would be working against each other.
    My question is, which is better for a person with elevated BP, K2 or this nattokinase? Can you elucidate?

    • Nevada_Smith says

      My wife is taking both nattokinase and K2. It it possible to get nattokinase with the k2 still in it such as in a product called Nattovena.

  45. Lynn C. says

    Hey Chris,
    I have been looking at the relationship between K2, D3, Calcium, and Magnesium. I was going to purchase Green Pastures Skate/Grass Fed Butter oil, Krill Oil, or Cod Liver Oil. There is a lot of information to read and understand – I think I am a little lost!
    Would I be better off with A combination of Natto, pasteured egg yolks, and a D3 supplement rather than the Skate/butter Oil?

    Or what would you recommend combo wise or product? I have to make sure I get enough D,K2, Calcium, and Magnesium because of some health battles.

    Thank you.

  46. Kendra says

    Dear Chris-thank you for sharing so much informative information. No one here asked about supplementing with ‘Natural Vitality Calm with Calcium’, and I have been taking it nightly for about 2 years. Now I am paranoid… It also contains Vitamin C as Ascorbic acid, D3 from cholecalciferol, Calcium from calcium gluconate, Magnesium from magnesium citrate, Potassium from potassium citrate, and Boron from boron citrate.
    I mostly take it to supplement, but also because it really helps me to have a bowel movement in the morning.
    Thanks, in advance

  47. says

    All this talk but few testimonials! Is the positive effect of vitamin k2 going to need 20 years of study and a team of 40 statisticians to detect an otherwise inmeasurable positive effect?

  48. Ross says

    Mr. Kresser,

    I’m having a hard time tracking down how much k2 is in kefir or yogurt or natto. Can you point me in the right direction?

    – Ross

    • says

      Old thread, but the answer is (maybe). Wheat grass and other leafy greens are a source of K1 not K2 and the conversion rate has not been determined for humans…

      “When animals consume vitamin K1, their tissues convert part of it into vitamin K2,14 which fulfills a host of physiological functions in the animal that we are only now beginning to understand. The ability to make this conversion varies widely not only between species14 but even between strains of laboratory rats,15,16 and has not been determined in humans. The mammary glands appear to be especially efficient at making this conversion, presumably because vitamin K2 is essential for the growing infant.17 Vitamin K2 is also produced by lactic acid bacteria,18 although bacteria produce forms of the vitamin that are chemically different from those that animals produce, and researchers have not yet established the differences in biological activity between these forms.”

  49. Amber says

    I believe I have a histamine intolerance and am getting tested for it (your article put me in the right direction! I can’t thank you enough!) so I’ve been following a low-histamine diet which is unfortunately very vegan. I was doing paleo/gaps prior and didn’t understand why I was still getting hives/migraines etc. (which, when reading the above, I think it was Sandra who asked why she would be getting hives with a k2 rich diet and I’m guessing histamine is why!) I can’t really do the fermented foods, meat or dairy very well, though I am forcing myself to eat some salmon every week and about to introduce raw milk again and see how it goes. Do you have any suggestions for getting K2 on a low-histamine diet?

  50. cobalamin says

    “The amount of vitamin K1 in typical diets is ten times greater than that of vitamin K2”

    This is false. Please provide a reference since K1 is ONLY found in the required amounts in leafy greens and we know that people eat very little or any leafy greens at all. Hence no intake of K1 and no K1 available to be converted to K2.

  51. Jess says

    Hi Chris, I went for water kefir crystals as I didnt fancy milk.

    I cannot find anything to tell me wheteror not this fermentation contains Vit K2?
    Some srticles suggest so but other only heap this in with the milk based kefir?

    • Steve says

      That means very little. It’s possible that means the mk7 form is lingering in the blood unused by the body; while the mk4 form is rapidly used by the body or sent to the tissues where it it needed.

  52. alison says

    I’m hearing a lot about Calcium supplements but not a lot about magnesium. Doesn’t magnesium need to be present for the absorption of calcium. So shouldn’t every one need to be taking magnesium with the calcium and K2?

  53. says

    What kind of Vitamin K2 to buy? There is only one leading brand and that is the norwegian MenaQ7. MenaQ7 is a product by the norwegian company Nattopharma.
    Please visit their webpage: and watch their animated videos!
    If you will want to buy Vitamin K2 as MenaQ7 I recommend
    By using referral code QAD201 you will have additional 5$ discount as a new customer.

  54. Herm Brownstein says

    Dear Chris, I recently came across your site while googling info re K 2 in low fat Edam vs ordinary Edam. My interest in K2 stems from my recent diagnosis by my new cardiologist – that my aortic valve is only opening 0.7cm vs 3cm fully. That started me on research to look for a way to stop or reverse the process. That led me to Dr James Howenstine’s article, “Vitamin K2 Controls Removal OF Calcium from Arteries……….” published in I’m greatly impressed by both of you – in part – because you both reference many of the same studies. Dr Howenstine tells of the dangers of coumadin, which I have been on for almost 10 years because of chronic AF. He also states it is easy to withdraw from coumadin and cites a number of supplements and dosages as substitutes. I’m now in the process of weening myself off coumadin.
    If you can recommend any specific supplements, I’d appreciate your recommendations.
    I’d like to add a few comments to your blog (feel free to edit any of the above):
    nattokinase is one of the best sources of K2 and most nattokinase on the market is devoid of it; one of your questioners complained of bone spurs and asks if D3 would help. Your answer refers to K2. I don’t believe D3 contains K2.
    Many thanks for a very informative column. browny

  55. Isobelle Phillips says

    Hi Chris, I am taking asprin because I have had a blood clot in my leg which travelled to my lung. I have rhumatoid arthritis which I am controlling myself without drugs by living on mostly raw foods with plenty of vegetable juices. I have had a bone scan and it has shown that I have bone thinning.I do take a calcium supplement in the form of Lifestream natural calcium. I want to take vitamin K2 in the form of natto capsules. Would it be safe to stop the asprin. If so would I wait a day or so before starting to take the K2.Thanks

  56. Patti Hill says

    Hi Chris,

    I want to give the Green Pastures FCOL/butter oil a try but am wondering which product people prefer, the capsules or creams. Also, in the checkout they have an area for coupons. Do you know of any discounts on the product now that I could use? I realize this blog is for K2 but could you direct me to a blog that specifically talks about FCOL/butter oil and its benefits.


  57. Lounett Holloway says

    Hi Chris,

    Great blog about K2! After read the wonderful benefits of K2 I am planning on take it . May God continue to bless you?

    Lynette (Nickmane)

  58. Chris Kresser says

    Hi anonymous,

    Overall I think vitamin D, magnesium & K2, as well as regulating cortisol and blood sugar levels, are more important for maintaining bone health than calcium supplementation – which can be dangerous in the absence of those other factors.

    FCLO/butter oil blend is the best product I’m aware of for fat-solube vitamin needs. It’s extremely effective, and a very high quality product. I use it with nearly all of my patients, and I take it myself.

    Yes, the research shows that synthetic vitamins and antioxidants are either not beneficial, or even harmful. That’s why it’s so important to get our nutrients from real food.

  59. anonymous says

    Dear Chris nice site. I was recently diagnosed with mild MS, I had very low levels of vit D but have been supplementing with d3 both with solgars cod liver oil and Thornes d3 powder supplement, i am concerned after reading weston price that my A to D levels are out of wack and as I have mild osteopaenia I am also worried about how to safely calcium supplement as Im aware that magnesium becomes a real issue for me with noise sensitivity and jumpiness. I do take a multi by Thorne which I rotate with a B group. Im thinking of starting fermented cod and butter oil, but would love to get some personal feedback and reviews [beside weston price]as to its effectiveness. Also with multis and the research into beta carotene, vit e etc, wasnt it a case of artificial beta carotene and only testing D-Alpha tocepherol rather than the multitude of tocepherols that occur in nature?

  60. Chris Kresser says

    I’m not a fan of calcium supplementation. 2,000 IU of D3 is probably good for maintenance, and 200 – 300+ mg of magnesium (depending on needs/goals) is good. Most Americans don’t need to supplement with calcium. They need K2, calcium and magnesium to put the calcium where it belongs – in the teeth and bones – rather than in the soft tissue.

  61. Tiffany says

    I received the product its called Intellikal plus ( Vitamin D3 1000IU, MenaQ7- (as menaquinone 7) 45mcg,  Calcium  (from calcium citrate) 400mg, Magnesium (from magnesium citrate) 200mg.  4 capsules a day. This product has less amount of K2, Calcium and magnesium compared to Natures plus.  Curious what is a balanced amount?

  62. Tiffany says

    I recently read an article in a news paper a week ago about vitamin K2 and its benifits with removing calcium from the arteries and placing the ca to bone.  The vitamin they were promoting was the “king of all calcium” because it included calcium, D3, mag, and K2 from the natto bean.  I have been reading your information about how K2 from natto bean needs to be fermented.  Would this be something to ask that company and its article if the vit D3 thats from the natto bean is fermented? Thank you

  63. Chris Kresser says

    I’m not too picky about vitamin K2 supplements, though I prefer to get as much of it from food as possible.  I explain how to do that in the article.

  64. Myrna James says

    Hi Chris,
     Recently on  I read a great article on K2 in the treatment of this disease …a Phase II trial.  i have a friend with this and after stopping a tough drug that didn’t work…  Revlimid. she showed her Dr. the article and now she is doing  15 mgX3 daily and Vit D3 at 5000 Iu/day + some B12.   Her RBC indices are back to normal and she is hoping to extend the time between transfusions.
     I found a source of K2 15mg at Vitamin Research Lab in Nevada. Her Dr. ok’d her
    to try this for 3 months.
      Any comment?  Other Vit K2 sources better?

  65. CJ says

    I’m 37 and I recently had a brief bout with heart palpitations (they’ve since gone away), and an Echocardiogram showed a small amount of mitral calcification.  Since the palpitations had gone away and I had no other symptoms, the cardiologist said no other action or follow up was necessary.  I did some reading and began supplementing my diet with 150 mcgs of MK-7 K2 from Jarrow. 
    Any hope that the K2 may help “de-calcify” my mitral valve and leaflets?

  66. Anna says

    Is it safe for someone on warfarin sodium / coumadin to take Garden of Life Raw Meal once a day everyday ? As I would like to incorporate into my morning smoothies to get nutrients I need as I don’t get all the nutrients listed on the nutritional label.

    It has Vitamin K2 in it in the form of Raw MK-7 at 80mcg ( 100% daily value ) ? Is 80mcg enough to benefit as I was said to have osteoporosis I am only twenty something ? Should I avoid Vitamin K1 that is in the Vega Health Optimizer ?

    I do appreciate replies.

  67. Chris Kresser says

    I’m not a fan of calcium supplementation, and your issue is one of the main reasons.

    You should not have calcium in your soft tissues.  K2 and vitamin D both regulate calcium metabolism, so you should definitely be normalizing your levels of both.

    I’ve never heard of K2 causing insomnia and can’t figure out any mechanism that could explain it.

  68. Tricia says

    A recent DEXA scan showed that I had “quite a lot” of calcium in my system.  Does this mean that I am absorbing the calcium supplements I take (i.e. not eliminating them in urine), but it is being deposited in the wrong place?
    I have begun to take K2 but wonder if it should be taken away from the calcium supplements in order to allow it to take action on the unwanted deposits.
    Should I reduce the calcium?  I take 650 mg together with magnesium, D3 etc.
    Finally are you aware of any reports of insomnia with higher doses of K2?
    I’d be very grateful for any enlightenment.   Many thanks.

    • Tonya says

      I know this is an old post, but the Thorne Vitamin K drops gave my son insomnia and generally made his disagreeable. He’s got loads of food allergies (IgE and intolerances). This was a single drop in a batch of gluten free pancakes.

  69. Tricia says

    Dear Chris
    I take Strontium Ranelate for osteoporosis.  As I’m sure you are aware, it has an uncommon side effect (1 to 10 in 1000) of blood clots.  I would like to take K2 but wonder if it would be contra-indicated with the strontium as K2 clots blood –  doesn’t it?
    If appropriate, what dose?
    Can you advise?   Many thanks.

  70. jackie says

    Awesome! Thanks for your reply! Would the fermented cod liver oil replace the Krill Oil? And, if I switched to that could I still take my multi-vitamin? The multi-vitamin is a whole food one.

  71. jackie says

    Hello, Chris! I just started taking the TriK Vitamin K supplement, and was wondering if the multi-vitamin that I am taking offers sufficient D3 (5,000 IU) and A (5,000 IU) to aid in absorption? I also take a Krill Oil supplement once daily. I am taking the supplement becuase I am genetically predisposed to heart problems and osteoperosis (both sides of the family) – I am 30 but don’t want to take any chances with problems down the line. Just wondering if this is a good idea? Thanks for your time!!

    • Chris Kresser says

      You should be fine. I prefer getting A & D from natural, whole food sources like fermented cod liver oil (from Green Pasture), but in terms of dosage you’re fine with 5,000 IU of both.

  72. Ann says

    Chris, thank you for you reply.  This info has helped.  I will make diet changes.  I know that I am not getting enough calories with vegan diet, but in going low-fat vegan, I was trying to lower cholesterol which has been high for years; plus, acidic animal foods supposedly make osteooporosis worse.   I am allergic to seafood, so can’t do fish or cod liver oil.  I do have Ann Wigmore’s books with instructions on how to make sauerkraut.  It is not easy  to find the right way to eat to obain better health.  This blog has offered more information that just reading an article would not provide.  Thanks again!

    • Marshal Garner says

      …it’s not possible to be “allergic” to fats, like Cod Liver Oil, etc, as you can ONLY be allergic to proteins.

  73. Ann says

    Chris, thanks for your information on K2.  I am researaching benefits of K2 for my situation.  I did not have osteoporosis until I had been on Advair for a few years for COPD from chronic bronchitis.  I have been on Actonel for 1 yr and 7 months.  Just had a bone density test that showed I have declined again, 12%.  Now at -3.3.  I have taken calcium supplements for most of my adult life and have been taking D3 and magnesium for several years.  I have a history of DVT, so I take Persantine, which is not a blood thinner, but keeps my platelets from sticking together.  I transitioned to vegan and have been free of animal products for one year.  I do not eat the high fat raw, but try to eat mostly fruit, veggies, legumes, and small amount of whole grains and try to keep fats low (nuts and EVO).  I am wondering if 1) K2 is right for me,  2)  if my diet contributed to the bad report,  3) would K2 help if I still have to take Advair (steroids).  Would Kefir have K2?  What about rejuvalac?

    • Chris Kresser says

      Ann: I don’t advocate a vegan diet for multiple reasons, and this is one of them. It’s impossible to get the nutrients (from food) necessary for optimal health with a vegan diet. I’ve written about that elsewhere on the blog. My recommendation for dealing with your problem would include a diet rich in grass-fed animal products, fermented cod liver oil (supplying A, D, K2, E and other quinones in their natural, whole-food form), and regular consumption of whole, fatty fish like salmon. K2 is certainly right for you, as is a whole-food form of D and A. Kefir probably does have some K2, since it’s fermented – especially if made with milk from grass-fed cows. Sauerkraut is another potential source.

  74. Jane says

    I am on a Calcium, Vitamin D supplement for thinning bones. It also has 45mcg of vitamin K2. Does this cause blood clots, since that what I understand vit K does? 

    • Chris Kresser says

      Vitamin K2 and vitamin K have different effects. K2 primarily regulates calcium metabolism (i.e. makes sure calcium goes into the bones and teeth where it belongs and not the soft tissue), whereas vitamin K has a stronger effect on coagulation.

  75. Linda says

    I’ve just come across your site & this thread on K2. I wonder if you’d share you thoughts on a a bit of a challenge we face at times in my health food store — how to best inform people who are taking blood-thinning drugs about the benefits of K2. We now just suggest that they ask their doctor about how to balance the K2 & the warfarin. We realize of course that virtually no PCP’s are informed on this.
         I myself take K2 & D3 daily, to help stop my body from taking calcium from my bones & then depositing it in joints, etc.

    • Chris Kresser says

      There are studies demonstrating that rats treated with high doses of warfarin develop arterial calcification, and that K2 protects against this. It can be speculated that humans who take warfarin also develop some degree of calcifications in their arteries, predisposing these patients to heart attacks and strokes. Unfortunately I haven’t seen human studies confirming this. On the other hand, the Rotterdam Study showed that K2 intake is associated with a significant reduction in CVD. And this study shows that K2 does prevent arterial calcification. So, although we don’t yet have all of the research we’d like to have on this subject, I think you can piece together a pretty strong argument for taking K2 with warfarin. The caveat is that K2 will probably lower the INR to some degree, so the PCP would need to monitor that.

      You could also educate them on using EPA & DHA at high doses as an alternative to warfarin. Studies have shown similar CVD-preventative effects, and of course EPA & DHA have benefits warfarin doesn’t have.

      • says

        In my analysis, very high doses of omega-3’s are lethal, although this is not yet recognized. High doses of omega-3’s change the bone marrow progenitor cells from a healthy balance of white and red blood cells to fewer white blood cells. “. . . omega 3 fatty acids impact hematopoietic differentiation by reducing myeloid progenitor cell frequency in the bone marrow and promoting progenitor cell differentiation.” I know of at least two cases where this became critical. I myself was taking 10 – 12 high purity omega-3 fatty acid capsules per day for cholesterol and sugar effects. A blood test revealed a dangerously low white blood cell count. When advised by my internal medicine doctor I dropped Omega-3 dosages to 2 capsules per day the white blood count came back up to normal.

        Another example is Dr. Timothy Shields, the MD who discovered the cholesterol effects of Omega-3’s. On his radio show he said he would take handfuls of Omega-3’s per day but only about 12 were effective and over that amount there was no more benefit but that there was no danger (that he recognized, parenthesis mine). It was reported on the radio that Tim Shields had died of a leukemia that was not related to the Omega-3’s (that they recognized, parenthesis mine.)

        Also studies have shown that too much Omega-3’s cause mice to change the numbers of bone marrow progenitor cells.

        My conclusion is that too much Omega-3’s cause low white blood cell counts which will lead to death if the dosage is not changed. Overly high doses of Omega-3’s for blood clotting treatment are therefore life threatening and will probably always lead to death unless the dosage is moderated.

  76. Chris Kresser says

    It depends on the person.  For the average, generally healthy person the fermented cod liver oil / butter oil blend is it.  Magnesium is difficult to get with a paleo/primal type diet, which is often what I suggest people follow, and many people are deficient in it so I may suggest that as well.  Overall my preference is always to obtain the nutrients we need from food, or at least food-based products like cod liver oil, when possible.

    Low WBC may indicate a chronic viral or bacterial infection, or it may simply be genetic.  If you’ve low WBC your whole life, and you aren’t symptomatic, I wouldn’t worry about it.

  77. Patti Hill says

    Thanks Chris.  I will look at their website.  You say this one of the few supplements you recommend everyone take.  Are there others and, if so, what? 

    On a totally unrelated issue, I have had low WBC counts for the last 10 years, possibly more, and it is low enough that doctors wanted to find a cause but, as yet, have not found one.  Do you have any knowledge on this?  My internet searches have not helped me and I’m not sure I should even be too concerned about it.  One person said that low WBC are not a diagnosis but simply a lab result that might have meaning, so don’t worry about it.   Do you have any thoughts?


  78. Patti Hill says

    Hi Chris,
    I am thinking of adding K2 to my vitamin regimen.   I have been taking over the counter calcium with vit. D for over 30 years which was prescribed when I had lupus.  It has been gone for 20 years but I still take calcium for mild osteopenia.   Over the years, I have developed many calcium deposits in my thighs and torso.  The doctors say it is nothing to worry about and they have no answer as to how to stop them or get rid of them.  Do you think the K2 might possibly help to get rid of the calcium deposits or keep new ones from occuring.  Also I eat a lot of store made saurekraut, not canned.  It is considered fermented?  I also eat 8-10 Egglands free range eggs a week.  Do you think the sauerkraut and eggs might provide enough K2 without the need to supplement? 
    Thanks for any advice.


    • Chris Kresser says


      Sauerkraut must be raw in order to be of benefit. The stuff they sell in normal supermarkets is pasteurized, which kills the beneficial bacteria. Health food stores in many areas do sell raw sauerkraut, or even better, you can make it yourself and save a ton of money.

      Eggs – even “free-range” supermarket eggs – are not as high in K2 as some fermented foods like natto and hard cheese. Butter is another good source, but it must come from grass-fed cows, and that’s not easy to find in some places.

      With your history you might consider the fermented cod liver oil / butter oil blend from Green Pastures. It has vitamin D, vitamin A and vitamin K2 as well as EPA and DHA together. It’s actually one of the few maintenance supplements I recommend everyone take, because of the balance of nutrients it contains. A, D & K2 work synergistically to promote healthy bones.

  79. ben nguyen says

    Neither has K2 in the MK7 form that comes from fermentation (natto etc)… they both contain K2 of the MK4 type (i.e. K2 that’s been synthesized by animal tissues)
    So that begs the question, which is better MK4 vs. MK7?
    Jarrow for example has an MK7 supplement:
    Interesting Study cited in this thread:

    • Chris Kresser says

      That’s a controversial topic, Ben. MK4 is the form synthesized from K1 by humans for their own use. Although they’re similar in function, MK-4 has effects on gene expression in bone tissue that MK-7 doesn’t have. I recommend using MK4 for this reason. See this post for more information.

  80. Chris Kresser says

    Unfermented soy is bad.  Fermented soy is fine in moderation.  Natto is indeed the best source of K2, but most people can’t tolerate the taste.

    I haven’t heard of a reliable blood test for K2.

    • Will says

      The small amount of natto – a teaspoon a day – is easy to take. If anyone says they can’t eat that amount because of the taste, that is ridiculous as it is easy to mix with peanut butter, jam, … the list goes on.

  81. ben nguyen says

    Natto (fermented soy beans) would seem like the perfect source for vitamin k2…   However, isn’t soy particularly bad?
    I’m guessing blood tests could be done to check k2 levels.. what would be a healthy number to shoot for?

  82. veronica says

    Hi Chris,I am in the process of getting dental implants but the bone graft I had done 4 months ago is not hardening as I hoped and was wondering if k2 with d3 would help.
    Thank you

    • Chris Kresser says

      I imagine it would, since K2 regulates calcium metabolism and directs it to the bones and teeth rather than the soft tissues.

  83. Barbara says

    Great info on K-2. I’ve been diagnosed with bone spurs in neck, spine, shoulder and hip and have severe pain. I don’t know if the bone spurs can be dissolved, but the remodeling of the bone via calcuim, D-3 and K-2 should be most helpful shouldn’t it?

    I’m not keen on taking Natto, have heard that taken in natural form it’s totally nasty tasting. I think I’d go with Kefir, sauerkraut, and the other recommended foods. I have recently been drinking pristine raw milk from grass fed Jersey cows. Too soon to notice any difference in calcium increase.

    • Michael says

      You don’t want to drink milk, grass-fed, organic or not.

      Dairy proteins contain growth factors that make a baby calve gain 300 pounds in a few months.

      It’s the grass-fed dairy fat that benefits humans, with K2.

      Brie cheese, Gouda… grass-fed dairy cheeses and butters and fermented foods.

    • says

      I took “Acid-A -Cal” a vitamin to get rid of Bones spurs..

      I had one in my foot, and in my throat from a car accident many years ago.
      I don’t know why this works but it does.. I bought it from Amazon..

      I now take Throne Liquid K2 Mk-4 for my Osteoporosis.
      It takes the Calcium to your Bones and NOT your arteries.

  84. Sandra Mennella says

    Since I have been taking Vit .K2 I am aware of a skin rash similar to hives.  Since my bones are deficient I have been taking an unusually high dose of K2 5000 mcg, Menatetrenone source.  I have read much information in your documentation but find no reference to  this subject.  Could you answer this concern for me.

    • Chris Kresser says

      I’ve never heard of hives as a response to high doses of K2, and I can’t think of an obvious mechanism, so I’m afraid I can’t help you.

  85. Roy Hartsell says

    I have read and read and nothing about K-2 and stents. Can I take MK-7K-2   with stents in my heart? Why does it say on the warning label not to take if you are on coumadin or other blood thiners? Thank you .Roy.

    • admin says

      The warning reflects a misunderstanding of the function of K2 in the body. Whereas K1 is preferentially used by the liver to activate blood clotting proteins, K2 is preferentially used by the other tissues to place calcium where it belongs, in the bones and teeth, and keep it out of where it does not belong, in the soft tissues (reference).

      As to whether it’s safe to take K2 with a stent, I don’t see why it wouldn’t be. In fact, vitamin K2 has been shown to reverse arterial calcification in rats. Nevertheless, you should check with your doctor on this question.

      • jarrod says

        Vitamin k2 can be converted to k1 and vis versa, so it can interfere with blood thining medication. Playing with nature while using medications is a dangerous practice.

      • Annie says

        Why are you not explaining about K2 Mk-4, and K2 MK-7?

        You just say K2..
        Big difference, and I think Your Very Misleading.

  86. Sharon Hunt says

    Hi Chris,
    Do you think if I made homemade yogurt from organic whole milk, and consumed around 4 oz a day  that I would get the necessary vit k2 amounts in my diet? I am kind of confused about the relationship between milk from a grass fed cow (where in the world can you buy milk from a grass fed cow in So. CA?) and the traditional corn fed cow milk (which I think is probably where all of our milk in the city comes from… even organic milk?). I am a lacto/ovo/ fish vegetarian.  I am also genetically predisposed to develop osteoporosis. Thank you for providing this valuable information!!!


    • admin says


      You can get grass-fed raw milk at Whole Foods in Southern California. That’s what I would recommend. But milk isn’t a sufficiently high source of K2. Raw, grass-fed butter would be higher, which you should also be able to buy from Whole Foods (Organic Pastures is the brand). Fermented cod liver oil with butter oil would also be a good choice. It can be ordered here. Finally, anything else fermented like kefir (which you can also make with the raw milk – do a Google search), raw sauerkraut (buy at Whole Foods or make yourself) or kim chi will be high in K2. You can also supplement with K2 using the MK-4 form. and other online companies have it.

    • kws says

      FWIW, cattle in commercial dairies are mainly fed alfalfa and/or grass hay, corn silage (the stalks & leaves are chopped up while the plant is green, and is partially fermented in storage) and other forms of roughage. When grain is fed to cattle it is to promote muscle gain and is mixed in with the other items I mentioned earlier in rations recommended by nutritionists. Feeding them grains exclusively would result in malnourished cattle and the farmer/rancher would go broke in the process since it would be very expensive.

  87. Alan Reith says

    What is the recommended minimum intake of Vitamin K2 per day for and adult male (me) with calcium in the arteries? Doctor has put me on Caduet (a statin I believe) which is giving me several unwanted side effects.
    I have sourced Natto (Nippon Food Supplies) and am planning to replace the Caduet with it.
    Any comments would be greatly appreciated.

  88. Ed says

    I think marrow also has lots of K2, so a good marrow bone broth ought to be a good diet addition. I’m still looking for a good reference, though, to support that.

  89. says

    My mother has been k2 for 3 months. She has recently noticed black patches on her face and arms, swelling on one side of face and inside mouth, pain behind her ear leading to her neck. Could this be a side effect of K2? She is on statins, and aspirin.

    • jarrod says

      Do not take stations and asparin while on significant doses of k2. K2 is regulator like vitamin the other medication will be affected by it, also vitamin k2 can be converted to vitamin k1 so it is possible to have overly thin blood which would allow local blood vessels in checks to bleed resulting in dark patches like bruising.

  90. KimC. says

    Wow, thanks so much for your prompt and helpful reply, Chris. I had no idea that “google scholar” existed. And yes, it was that sentence that caught my attention: K2 is preferentially used by other tissues to deposit calcium in appropriate locations, such as in the bones and teeth, and prevent it from depositing in locations where it does not belong, such as the soft tissues.(Spronk et al., 2003, pp. 531-537
    Thanks again and best wishes to you in your academic endeavors.

  91. KimC. says

    Oh, I hate to be a bother when you’re busy trying to complete your studies, but this is of great interest to me as my husband suffers from DISH – Diffuse Idiopathic Skeletal Hyperostosis – essentialy calcification of the anterior ligaments of the spine. Although quite rare in a man of his age (he’s only in his late 40’s), his Rheumatologist has told him that dietary changes would not make a difference, but I wonder if K2 supplementation could be of assistance here.

    I’ve been unable to find the original Spronk research article quoted in your post and any assistance in locating it, if at all possible, would be greatly appreciated.

    Thanks so much for your terrific blog.
    Kim C.

    • Dee T. says

      I noticed you mentioned DISH. There is a forum on Facebook for that. If you need support and more info.
      I was wondering how K2 would work with dissolving the calcium from DISH which attaches and flows across the ligaments like melted wax. Do you think this might be a possibility?
      Hoping this might help slow the progression of this long thought rare form of Arthritis.
      Thanks for the info.
      Dee T.

  92. Ben Foster says

    Chris: Re:K2 studies showing reduced prostate cancer risk. But the studies point to dairy sources of K2, e.g.cheeses. Dairy is implicated in prostate cancer. So: Is it good or bad for prostate health to eat cheeses? And what of nattokinase supplements instead of natto? Does miso fit into the K2 picture?

    • says

      from what I understand from my vitamin bottle nattokinase supplements have no vitamin k2 in it but you can buy vitamin k2 easly… the kind I use Now food vitamin k2… $8.28 at Iherb. If you are a first time customer you can get $5 off your order if you spend under $40. or $10 off your first order if you spend over $40….. the coupon code is.. ULO354 they have a lot of other kinds of K2 but I found that one most economical and 100mcg

      • Nevada_Smith says

        While most good K2 supplements have the K2 removed, it is possible to find nattokinase with the K2 still in it such as the product called Nattovena. think it is a dumb thing to do to remove the K2. K1 is the coagulation vitamin.

  93. Ben Foster says

    Dear Chris,
    I’ve only recently come across the K2 studies. They raise a series of questions for me. My major concern is prostate cancer, and I am intrigued by the studies showing a reduced danger of advanced prostate cancer for men who consume more K2. But the sources for K2 are primarily animal, especially dairy. This finding directly disagrees with many other recent finding that correlate high dairy intake with high risk for prostate cancer. The Japanese, who eat little dairy, have one quarter the prostate cancer that we Americans suffer. In countries with high dairy intake, prostate cancer rates are also high. Colin Campbell in The China Study asserts that diary interferes with the body’s use of vitamin D, and that high dairy intake causes an enormous increase in aggressive and advanced prostate cancer. Campbell recommends a vegan diet–no animal based food at all. He claims that population studies demonstrate that vegan populations do not suffer from the  high incidence of cardiovascular disease and cancer that we in the West do with our diets heavy on animal protein. Campbell asserts that it is the protein especially in dairy that makes it so harmful to Western diets. In the recent study of K2, cheeses, especially Gouda and Edam, were recommended as sources of K2. Since this contradicts so directly the findings of Campbell, I am puzzled. But also hopeful. Because of my prostate cancer fears, I have given up nearly all dairy, and the part I miss most is cheese. How I would love to find out that at least some cheeses come in with  a clean bill of health in regards to the prostate. My other questions are these: does miso qualify as a source of K2? What about supplementation with nattokinase? Nattokinase supplements are easy to come by, but natto is scarce in these parts, and I’m not eager to make my own. Sorry to throw so many questions at you. Credit it to your raising important issues.

    • says

      the chinese make fuyu which is fermented soya bean paste… after trying the Japanese frozen natto for 3 serving $4.50 and the Chinese… several servings $2. in a jar I do like the fuyu best… Also from what I understand any excess k2 the body gets rid of in 24 hours.

      • Annie says

        Pat ,
        This is a old post, but you say K2 leaves the body in 24 hours. You need to say what K2 you are talking about.
        K2 MK-4, or K2 Mk-7.

        That only happens with K2-Mk4 and that leaves the body in about 4 to 5 hour. I should be taken with food, and A little healthy fat.. every few hours.

        K2 Mk-7 is a whole different bred so to speak of k2.
        Mk- 7 can stay in the body for a couple of days, and it also can give you a rapid heard beat, depending on how much you take!..
        You really do not need Mk7 everyday..

    • Diana says

      Hi Ben,
      Please read Denise Minger on the China Study. Campbell has been cherry picking. Denise put all the data together and came to very different conclusions than Campbell.

    • Joe says

      I had same questions.. Read Devil in the Milk an all your questions are solved.. Now i have a different question (hours an months of study an attempts to purchase u will understand why)… Is aged goat cheese an cow cheese all same when talking K2 ?? Help

  94. roni says

    hi again chris, i have another question for you. what do you think of bragg’s liquid amino’s?    thanx.

  95. roni says

    hi chris,  thank you for this information! until recently i was unaware of the research findings on k2.  i wonder if you have any idea what a good amount of k2 per day is, and what is the designation for it? units? micro or miligram?  and lastly, any idea of the amount of k2 in trader joe’s organic low fat yogurt?  does the lower fat content lower the k2 level?
    thanx for your reply.

  96. says

    Both natto and sauerkraut can be purchased at health food stores.  It’s important to get organic natto made from non-GMO soy.  See the posts earlier in this thread for more info.

  97. Judy says

    Does this have to be made or can it be purchased somewhere like whole foods markets, etc.  How do you prepare it?

    • says

      YOur best choice would be natto which is the organic soya fermented from Japan, I found it in the freezer section of the Oriental grocery store… however the Chinese make a fermented soya also organic non gmo called fuyu .. It seems a better buy… Little squares like cheese comes in a jar…$2 for several servings… I did it with rice and kale..

      • Richard says

        Many times you get what you pay for. Proper natto has been made with Bacillus natto and has much more K2 than fermented foods.

  98. says


    It is a common misconception that Asians eat “a lot of soy”.  In fact, that’s not true.  Soy has traditionally been used as a condiment in Asia, and even then it was carefully prepared (through long fermentation) to destroy the phytates found in soy that inhibit nutrient absorption.

    Many vegetarians in the USA, and Europe and Australia would think nothing of consuming 8 ounces (about 220 grams) of tofu and a couple of glasses of soy milk per day, two or three times a week. But this is well in excess of what Asians typically consume; they generally use small portions of soy to complement their meal. It should also be noted that soy is not the main source of dietary protein and that a regime of calcium-set tofu and soymilk bears little resemblance to the soy consumed traditionally in Asia.

    Perhaps the best survey of what types/quantities of soy eaten in Asia comes from data from a validated, semi quantitative food frequency questionnaire that surveyed 1242 men and 3596 women who participated in an annual health check-up program in Takayama City, Japan.  This survey identified that the soy products consumed were tofu (plain, fried, deep-fried, or dried), miso, fermented soybeans, soymilk, and boiled soybeans. The estimated amount of soy protein consumed from these sources was 8.00 ± 4.95 g/day for men and 6.88 ± 4.06 g/day for women (Nagata C, Takatsuka N, Kurisu Y, Shimizu H; J Nutr 1998, 128:209-13). 

    According to KC Chang, editor of Food in Chinese Culture, the total caloric intake due to soy in the Chinese diet in the 1930’s was only 1.5%, compared with 65% for pork.

    Compare that to the 220g that the average American consumes in a single 8 oz. glass of soymilk.  What’s more, almost all processed food these days has some form of soy in it, whether in the form of soybean oil, soy protein, soy flour or soy lecithin.  The reality is that most Americans – especially those who are “health conscious” – are consuming far more soy than Asians ever have, and far more than it is healthy to eat.

    Did you read any of the information I linked to?  I’d really recommend you do that before making up your mind one way or the other.  Here’s a direct link to the study which demonstrated a significant decrease in sperm count in males consuming as little as one cup of soy milk per day.  It was published in a major, peer-reviewed journal by a reputable researcher working at the Harvard School of Public Health. 

    I’ve written about other dangers of soy consumption on this blog (I provided the link in my previous post).  There is overwhelming evidence that soy is harmful too our health in the quantities we’re consuming it in.  This is true whether the soy is organic or not. 


    • Robert says

      I absolutely do not believe that 4-5 servings of soy a day is dangerous. It sounds like you have been reading the drivel served up by the Weston Price people. Soy has in fact been shown to help prevent breast cancer.

      Also, what modern Japanese eat has little do to with what was previously consumed. Even now, edadmame is eaten frequently and it is no mere 8 grams that are eaten either.

    • Richard says

      No idea about where you got your information on people in Asia not eating much soy but it is totally wrong. Next you will be saying the Japanese do not eat natto.

      The Japanese and Chinese have a large amount soy at least weekly, which is much more than the Western Diet, and a small amount daily. Not only is tofu popular in both countries but Kikkoman Soy Sauce popular in Japan is made from soybeans.
      Neighborhood food markets in China have large slabs of fresh tofu which customers cut and place in a bag to be weighed at the counter.

  99. carl says

    That is hard to believe as they eat a lot of soy in China and it doesn’t look like they have problems with feritlity as it is the world’s most populus country; my soy yogurt is organic soy;

    • farseas says

      I came here looking for the answer to this exact question. But I was wondering about K2 in other fermented soy products, specifically kefir.

  100. says


    I’m not aware that K2 has any specific effect on blood pressure.  While I can’t provide any medical advice, as I’m not a doctor, I can tell you that there are several ways to lower blood pressure naturally, including stress reduction, meditation, acupuncture, and dietary therapy.  Meditation is particularly effective, and is completely non-invasive – not to mention free!

    • John says

      From my understanding, Vit K2 deposits calcium where it belongs, such as bones and teeth. It does work with Vit D and magnesium to do this. With the absence of Vit K2, it is also my understanding (from much research) that calcium is deposited in the arteries…. aka arteriosclerosis.
      Apparently, Vit K2 assists in the repair of arteriosclerosis.
      Therefore… it is easy to conclude, that given enough time (how long is a piece of string) that K2 may indeed improve blood pressure BUT for a more immediate effect, you cannot go past Hawthorn Berry syrup. This dilates the arteries and veins (most people on the SAD diet will have hardened arteries, also a cofactor in heart disease and High Blood Pressure).
      Hope this information is helpful.

  101. rose tubbs says

    I have been on HBP medication which includes calcium chanel blockers (admittedly a small dose) for nearly 3 years -monitoring shows blood pressure now well controlled but I hate taking pharmaceutical drugs. Dr is very loathe to give me info on this drug and I have always wondered what would be the natural alternative. With your info it seems to become a bit clearer and I would lke to take a little K2 or at least eat sauerkraut and more cheese & egg yolk. What do you think?

  102. Jean says

    Hi, I have bone spurs on my heals. It would be great if vk2 worked to heal them. I quit my job as a PE teacher becuase of the pain. I am just hoping to find some that isn’t made from gentically modified soy beans.

    • alison says

      I did B12 injections. It worked great the only thing is you have to give yourself injections every day. I went to a functional medicine doctor.

    • annie says

      I realize these posts are old, and by this time your heel spur is gone (I hope).

      K2 MK4 did not take my spurs away, but “Acid A Cal” took my heel spurs away, and a spur in my throat.
      It can be bought at Amazon…

      I have nothing to do with Acid A Cal or Amazon…
      Just wanted to share this with you, and hope it can help other people..
      Btw it is a vitamin, and why this combo works , I have No idea, but it has for me, and others that I have told about it..

      Take Care,…

      • Dee says

        Jean, spurs in your throat and in your heel…sounds like DISH Arthritis to me. I have it, Can you tell me more about Acid A Cal? If you would like to know more about DISH, do a search then if you chat with your doc, (s)he may or may not be familiar with it. If you want to know more, contact the DISH forum on facebook.

    • bob kusek says

      Hi ,Jean. I removed bone spurs in my shoulder and rist. I STOPED EATING GRAINS and COMSUMING SUGAR, MEATand DAIRY .That is a Vegan lifestyle. princibly a diet of fruits , berries , and melons. Clean your lymph system through movment , massage , sweating , tone the kidneys flush the bowels. link on to robertmorsend / utube videos.

      • jarrod says

        I wonder how vegiterians get enough vitamin q10 , b12 , vitamin k2 mk4&mk7 collegen glucosamine. I have wondered about going vegetarian.

      • Richard says

        Bob, because you stopped consuming grains is not related to a vegan diet, which does include grains if desired.

  103. Carol Hitchcock says

    So grateful for the info on K-2.  I’m just discovering this and have just discovered at the age of 67 from a cat scan that I have minimal calcification and minimal calcium deposits in my main aeorta in the stomach area.  It is so satisfying to have an answer and unfortunately most doctors don’t seem to offer this as they are more of a reporter and less of a problem solver or researcher.                                                  Thanks so much!                                 Carol 

  104. Peggy says

    I have found an organic natto at our local Japanese market, Nijiya Market, a chain in CA. They also feature several non-GMO versions. You could also make your own (Gold Mine carries the starter, as does Nijiya Market). The food is the best way to go if you can eat it. Then you also get nattokinase benefits (helps dissolve clots) as well as the K2. About 1/4 of a 100gm pkg eaten every other day should protect you well enough due to the MK-7 long lasting form of K2. BTW, natto can be frozen and re-frozen without significant loss several times.

    • Chip says

      Regarding freezing natto, do you have any information as to whether freezing reduces the content of K2? I believe I’ve read that freezing does significantly lower the amounts of some vitamins, like B6.

  105. says

    Hi, Does any one no where I can buy vitk2 Natto that is non gmo and certified organic? I just read an article stating that many of the soy beans grown in the US that have been sold to Japan have tested positive for gmo even though they were organic. I would like to buy the food instead of the suppliment in hopes that it is cheeper but also pure. 

  106. says


    Thanks for your comment.

    Kefir definitely has more K2 than milk, as K2 is a product of bacterial fermentation. Natto, a fermented soy product, is the highest natural source of K2.


  107. says

    Excellent article! I’d be interested to find out if kefir has more K2 than the milk it is made from. I would not be surprised if it did.

    I added the little bit of K2 data for food that I could find to my Excel dietary nutrition calculator. Most of what I found came from Chris Masterjohn’s WAPF article on K2 in Wise Traditions.

    • Fat Albert says

      Anybody have any idea ,at all, where one can “obtain” ( purchase) vitamin K2!!?? And, by the way folks, be careful where you purchase “natto.” Natto is a product that contains a lot of vitamin K2. Avoid “Doctor’s Best” nattokinase ( concentrated natto .) The “FOOLS” removed all the vitamin K2 from the product!!! Why they did that, I’ll never know!! It’s the Vitamin K2 that makes the stuff “effective” when it comes to clearing blocked arteries!!!!! Nattokinase without vitamin K2 is like a car with NO BATTERY!!!! Don’t buy “Doctor’s Best” nattokinase. You’ll waste your money.

      • Alexis says

        I buy my k-2 from They have a lot of different brands, etc. They are very fast and very reasonably priced as well.

        • bob james says

          Just be careful when ordering from If you click on the “address verification” button they give your information to Experian, the credit reporting agency.

          That’s right! Despite their promise not to give your info to any other party, they do it every day with Experian.

      • Richard says

        They are not the fools….you do not know what nattokinase is otherwise you would know it does not contain any K2…

        • Nevada Smith says

          nattokinase does contain K2 but the manufactureres removed it because they think it will interfere with the blood thinning qualities of nattokinase. Nattokinase is a metabolite of Natto, the fermented soybean food product and it too is a good source of K2 as the articled states.

          Chris DOES know what he is talking about. Contrary to popular belief, studies actually show that persons taking drugs to thin their blood do better when they take K2 along with their drugs.

          You can purchase nattokinase with or without K2 in the formula. The more expensive products have K2 removed but I believe this is a huge mistake. I therefore take k2 with my nattokinase. K1 is used more for clotting than K2 is.

      • whitney says

        I purchased Cardio Assurance from Nature’s Sunshine which contains K2(MK-7) and Googled it and found this wonderful article! :)

      • Sally Lehrman says

        I just bought some the other day from Amazon: both the Thorne K2 (liquid) and the the Life Extension Brand of Super K2 (capsule) and I will soon buy the highly touted book “Vitamin K2 and the Calcium Paradox: How a Little-Known Vitamin C…” — Happy shopping!

      • Patricia says

        I get mine online
        It is made in USA; head office is in California. That’s why delivery and handling is free in USA. Delivery took about 3 to 7 days. It has Omega 3+ as well as CoQ10 and Vitamin K2 and it is Extended release(long-term effect).

      • abby100 says

        Puritan’s Pride is a great online resource for vitamins and minerals including K2 which is a tan gel small like D or E.

      • Jared says

        While obviously the best source of vitamin K2 (Mk-4 and Mk-7) is from whole foods. There is a supplement I take that contains both types in it called the Daily Multi Nutrient. I think it’s a good option, especially considering some of the preliminary research behind supplemental K2.

      • says

        There is a difference between K2-MK-4, and K2-MK-7

        That said, when you refer to K-2, you all need to say which one, since there is a Big difference.

    • Richard says

      Sauerkraut does not have a large amount of K2…nor does miso.

      Natto is head and shoulders above any other food item…

  108. says


    Whenever possible, I prefer to get necessary nutrients from food sources. In the case of K2, you can eat fermented foods like sauerkraut, kim chi, kefir, yogurt and natto. Hard cheeses, grass-fed butter, egg yolks and chicken liver are also good sources.


  109. says

    Hi Carl,

    My guess is that soy yogurt doesn’t have much K2. Commercial yogurt is not fermented for very long, so the amount of K2 produced in the process is likely to be fairly low. Regardless, I wouldn’t recommend soy yogurt for other reasons. Soymilk, which soy yogurt is made from, is highly processed and poses many risks to health. As little as one cup of soy milk per day was recently shown to significantly reduce sperm counts in men, and it can cause similar hormonal problems in women. Please see my recent articles on soy for more information.

    If you’re eating soy yogurt because you’re sensitive to dairy products, try making yogurt at home from scratch. If you ferment it for 24 hours or longer, all of the lactose will be consumed by the probiotic organisms. Many people who are lactose-intolerant are able to eat yogurt when it’s made this way. Plus, the longer fermentation time means that the K2 content will be much higher – especially if the yogurt is made from whole milk that comes from grass-fed cows. Rapidly growing green grass (in Spring and Fall) is very rich in K1, which cows convert to K2. That’s why grass-fed butter and milk/cheese are high sources of K2.


  110. says

    Hi Roni,

    Here’s a list of the vitamin K content of various foods, measured in micrograms. I recommend reading that entire article, actually.

    I don’t recommend any low-fat products, including low-fat yogurt. See here for an explanation. The fat is where all of the fat-soluble vitamins will be found, including K2. Therefore low-fat yogurt will have less K2 (and other beneficial nutrients) than whole-fat yogurt.

    I don’t recommend a specific target for K2. I suggest that people eat plenty of fermented foods (sauerkraut, kefir & yogurt made from grass-fed milk), grass-fed butter, hard cheeses, and egg yolks (from pasture-raised chickens). If you do that, you’ll get all the K2 you need.


  111. says

    I don’t recommend Bragg’s for two reasons:

    1) Like most products with “spices” or “natural flavors” listed as ingredients, Bragg’s contains MSG. The industry avoids listing MSG on the label by putting MSG in spice mixes, and if the mix is less than 50% MSG, manufacturers don’t have to put it on the label.

    2) Too much processed soy can cause numerous health problems.


  112. says


    I haven’t had a chance to review the studies you mention linking dairy consumption to prostate cancer risk, but I am skeptical. Were they observational studies? Were they well-designed? Did they control for other dietary factors? What type of dairy products were they? If the studies were anything like the recent study which “proved” that eating red meat is bad for you (see my article Where’s the Beef for more on that ridiculous claim).

    Along those same lines, before you put too much stock in Campbell’s China Study, I’d highly recommend reading this review of his book. Make sure to read Campbell’s response to the review, and Masterjohn’s response to Campbell. Many of the claims made by Campbell aren’t even supported by his own data. That’s unfortunately all-too-common when study authors have a strong agenda, as Campbell did.

    Also keep in mind that pasteurized dairy and raw dairy, which is what I advocate eating whenever possible, aren’t the same foods. Raw dairy still contains all of the enzymes and probiotics naturally present in the milk. You could say it’s a “whole food”. The pasteurization process (high heat) kills those enzymes and probiotics, which makes pasteurized dairy more like a processed food. Many people don’t have lactase in sufficient amounts to digest the lactose in milk; that’s why people like me thrive on raw milk but cannot tolerate much pasteurized milk at all.

    K2 must always be consumed with adequate amounts of D and A. That’s just one of many reasons why a vegan diet is a bad idea.

  113. says

    Hi Kim,

    I’m sorry to hear about your husband’s condition. I’m not familiar with it specifically, so it’s difficult to say whether K2 supplementation would help. However, as K2 regulates calcium metabolism in the body (putting it where it should be, and not where it shouldn’t be), I imagine it may be helpful. Unfortunately I don’t have the original Spronk article any longer. Here is a search for “spronk k2” on Google Scholar. You might want to check through the results. Also, if you haven’t already read it, I highly recommend checking out Chris Masterjohn’s article on K2 on the WAPF website. Good luck!

  114. says

    Hi Mona,

    I’ve never heard of K2 causing any side effects like the ones you mention. I think it’s far more likely that the statins are causing those problems, but it’s impossible to say for sure. Have you read my articles on statins? They are not proven to be beneficial for women of any age. Perhaps your mom should consider discontinuing them.


  115. Angie says

    The Bragg’s website says:
    Bragg does not add any MSG to its liquid amino products. However, MSG is found naturally occurring in many foods, such as mushrooms, tomatoes, parmesan cheese, and soybeans. Since Bragg Liquid Aminos is made from soybeans, there can be some very small amounts of naturally occurring MSG. Patricia Bragg is personally very opposed to adding MSG as a food ingredient to foods, and she is very sensitive to MSG.

  116. Mike says

    Hi Chris,

    I just had a body scan that indicated my bone density is low, and I recently was diagnosed with gout also (which subsequently seems to have come under control through frequent Korean Vinegar drink consumption).

    I found this product after getting recommended K2 and D by the BodyScan professional who seemed well researched in naturopathy:

    Sorry to ask – but is there anything to watch out for in supplements or anything particularly good?

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