Vitamin K2: 9 Uses and Benefits

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Vitamin K2 is an essential vitamin that many people never hear of until they have their first child and the nurse administers a Vitamin K injection.

Sadly, this essential nutrient is often overlooked, and it is important at all life stages, not just for newborn babies or pregnant moms. Other vitamins and minerals like Vitamin D, Magnesium and Calcium get the attention they deserve, but K2 is often ignored with dire consequences.

What is Vitamin K2?

Vitamin K is a fat soluble vitamin that is important for blood clotting and that contributes to a healthy heart, bones and immune system.

There are several different forms, mainly K1 and K2, though they act differently in the body:

  • Vitamin K1– (or phylloquinone) is natural form found in greens and nettle that is used by the liver for proper blood clotting.
  • Vitamin K2– (or menaquinone) is a more absorbable form of Vitamin K found in certain fermented foods and supplements is used by soft tissues and is helpful for bones, heart tissue and more
  • Vitamin K3– (or menadione) is a synthetic form of Vitamin K. This is typically the one injected into infants at birth and some studies have shown potential toxicity from this form

Which Form of Vitamin K2 is Best?

Vitamin K1 is found in leafy greens, though only a small amount is actually absorbed and used by the body. In fact, experts suggest that only 10% of Vitamin K1 from greens is used by the body.

Vitamin K2 is found in fermented raw grass fed dairy and certain other fermented foods (like natto). This is because K2 is a product of the fermentation and is created by certain bacteria. In general, these foods contain a proportionately lower amount of K2 (compared to the K1 in greens), though much more is absorbed. (1)

Interestingly, studies have shown great health and cardiovascular benefits from K2, but hardly any effect from K1. K1 is necessary for proper blood clotting and is used by the liver, while K2 benefits the bones and controls proper utilization of calcium. In fact, it is helpful to think of them as two separate nutrients with different purposes.

There is also a misconception that the body can convert K1 to K2. The research actually showed that while some other animals can effectively convert K1-K2, humans need food or supplemental sources of K2 for good health. (2)

Chris Kresser explains why the K1->K2 conversion is not effective in humans:

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)

Are We Deficient in Vitamin K?

Estimates are that over half of the adult population is deficient in Vitamin K.

While the effects of Vitamin K deficiency can show up in more serious problems like cardiovascular disease, bone loss and tooth decay, it can also manifest in smaller symptoms like easy bruising, heavy periods, or nosebleeds.

Those with digestive problems or with a history of antibiotic use are the most at risk for these problems.

In general, it would be a good idea to get adequate K1 and K2 from diet and supplements, though K2 is the most studied and effective for the benefits listed below.

For the rest of this post, I’ll be using the terms “Vitamin K” and “K2” to refer to the K2 form of Vitamin K.

Uses for Vitamin K2

So why is Vitamin K so important for optimal health anyway?

1. For Healthy Bones

Research has shown that Vitamin K2 is one of the most important nutrients for long-term bone health and that it is even more important than calcium.

K2 is needed to help calcium and other minerals bind into the bone matrix to strengthen bones (and not to stay in soft tissue where it can cause calcification in the wrong places).

In fact, studies have shown that Vitamin K is effective at not just stopping bone loss in people with osteoporosis but potentially reversing it as well.(3) This same research found up to an 80% reduction in fractures in osteoporosis patients with K2 supplements.

2. For Heart Health

I wrote before about how calcification of the arteries can occur when a person consumes too much calcium without the needed cofactors in the right ratios: Magnesium, Vitamin K2 and Vitamin D3.

The book Vitamin K and The Calcium Paradox details how Vitamin K is needed to usher calcium into bones and other necessary places in the body and keep it out of soft tissue, arteries and the heart. Magnesium is also important for this process and without the needed K2, D3 and magnesium, calcification is more likely.

It is important to note that the research only shows a cardiovascular benefit from K2 and not K1. In fact, the Rotterdam study found that those with the highest dietary or supplemental intake of K2 had the lowest risk of calcification of the arteries, and the lowest risk of getting or dying from cardiovascular disease.

With the drastic rise of heart disease in recent decades, Vitamin K is becoming an ever-important topic.

3. For Oral Health

Oral health is vital for overall health and Vitamin K is important for oral health. In fact, Vitamin K was one of the vitamins that Dr. Weston A. Price found was vital for tooth remineralization and prevention of cavities.

I used it as part of my tooth remineralization process that helped me reverse several small cavities. (I recently confirmed that remineralization is possible in an interview with a dentist who specializes in this process- listen here)

4. To Reduce Varicose Veins

This will be getting its own post soon, but the same action that makes Vitamin K beneficial for bone health may also make it helpful for those with varicose veins. (4)

Human research is still in the early stages, but we know that Vitamin K is needed for the production of MGP (matrix GLA protein), which helps avoid calcification in the arteries. This same protein helps stop calcification in the veins as well since the calcium meant for the bones is ushered into the bones and does not accumulate in veins and arteries.

The preliminary study published in the Journal of Vascular Research found that Vitamin K2 was necessary in reversing the chemical change and avoiding or getting rid of varicose veins.

More research is needed, but since Vitamin K has so many other benefits, it might be worth trying for those who struggle with varicose veins.

5. To Reduce Cancer Risks

There are several well-documented studies that show a correlation between higher Vitamin K consumption and lower risk of certain cancers:

  • A European cohort study showed that K2 may reduce the risk of prostate cancer by 35%  (5)
  • A follow up study showed a 63% reduced risk of prostate cancer in those with the highest Vitamin K intake vs. the lowest (6)
  • A 2003 study showed a benefit of K2 in slowing the growth of lung cancer and leukemia cells.
  • It is also shown to reduce the risk of and halt the growth of hepatocellular carcinoma, a dangerous type of liver cancer. (7)
  • It impairs the ability of cancer cells to stimulate tumor growth (8)
  • Stop the proliferation of cancer cells (9)

Life Extension Magazine reported that:

Lab studies demonstrate tremendous potential for vitamin K in many other cancer types as well. Vitamin K2 induces certain kinds of human leukemia cells to differentiate, or turn into normal white blood cells. In cells from certain brain tumors, in stomach cancer, and in colorectal cancer lines, vitamin K halts the reproductive cell cycle and induces apoptosis. Vitamin K also triggers a DNA-degrading protein that cancer cells normally suppress; thereby preventing tumor cells from repairing themselves effectively.

More research is definitely needed, but these initial studies show that Vitamin K may be an effective (and inexpensive) possibility for the future of cancer treatment.

6. For Brain Health

Some fascinating new research showed that the same process that makes Vitamin K helpful for preventing calcification of the arteries and muscle tissue might also make it beneficial for protecting the brain against Alzheimers and other diseases.

In short, the theory is that Vitamin K helps prevent excess calcium in the body (including the brain), and this excess disregulated calcium in the brain accounts for some of the damage from Alzheimers.

Another study looked at the dietary intake of Vitamin K in patients with early Alzheimers and found that those diagnosed with Alzheimers had considerably less Vitamin K than those in the control group. (10)

7. Longevity

We now know that Vitamin K affects 16 Gla-proteins in the body. This is one of the reasons that studies have consistently shown an inverse relationship between Vitamin K levels and mortality from all causes. (11) In other words, the better your Vitamin K levels, the less likely you are to die from all causes. (12)

In fact, the most recent study showed that those with the highest intake were 36% less likely to die from all causes than those with the lowest. (13, 14)

Of course, all of the above benefits show why it would logically have such an impact on mortality by reducing the risk of death from the main causes like atherosclerosis, osteoporosis, diabetes, and cancer, but it appears that there is a dose dependent correlation with Vitamin K intake:

Insufficient blood clotting was thought to be the main sign of vitamin K deficiency. However, scientists have since learned that you can have enough vitamin K to promote healthy blood clotting, yet still not have enough vitamin K for it to activate the Gla-proteins necessary to help prevent cardiovascular disease, osteoporosis, diabetes, and cancer, all conditions in which vitamin K-dependent proteins are known to be factors. Fortunately, studies show that vitamin K supplementation can significantly increase the amount of activated Gla-proteins in tissues—without over-activating the clotting proteins.(15)

8. Synthesis of Other Nutrients

I already mentioned how Vitamin K is needed for proper calcium synthesis (along with magnesium) but it is also needed in balance with Vitamin D3.

K2 and D3 work synergistically for many aspects of health. In fact, Calcium, Magnesium, K2 and D3 all work in balance. Taking too much D3 can cause a Magnesium deficiency without supplemental magnesium. Taking too much calcium can cause a magnesium deficiency or lead to over-calcification.

Vitamin D helps you absorb calcium, but K2 helps it actually end up in your bones and Magnesium helps make sure it gets there efficiently.

9. Skin Health & Anti-Aging

K2 is also promising for skin health and anti-aging. Just as it prevents the calcification of arteries, veins and soft tissue, it helps stop excess calcium in the elastin in the skin.

For this reason, K2 may help keep skin elastic and prevent wrinkles.(16)

2011 research showed that women with extensive wrinkles were also more likely to have low bones mass. Other research has shown that Japanese women were less likely to have wrinkles than other cultures, and noted the natto (fermented soy high in K2) in the diet of Japanese women.

How to Test for Vitamin K2 Deficiency?

You can measure serum K1 and K2, just like you can measure D3, but unfortunately, this is not extremely accurate, since K1 is held in the liver and has a short half life (about 4 hours). Essentially, a serum K test would only reveal Vitamin K levels from food intake in the last day or so.

There is a more advanced test, called the enzyme-linked immunosorbent assays (ELISA) that tests the presence of MGP. Initial reports on this test showed that almost 100% of people tested were deficient. The doctor who developed the test, Dr. Schurgers, suggests that almost everyone could benefit from increasing dietary and supplemental levels of K1 and K2.

How I Take Vitamin K2

Since there are no known side effects from K2 consumption, even at high levels, I take 180 mcg (two 90mcg capsules) per day on most days (consuming a small amount of Natto would also work). I also consume Fermented Cod Liver Oil Daily, which is a natural source of K2 (and other fat soluble vitamins), as well as Emu Oil (a natural source of K2). Raw butter from grass fed cows is also a good source of Vitamin K2 for those who tolerate dairy.

Some experts recommend as much as 500mcg per day, but I would only consume high levels like this under the guidance of a practitioner to make sure that cofactors (D3, calcium and magnesium) maintained proper levels as well.

For K1- I eat a lot of leafy greens and use nettle leaf (high in K1) in many of my homemade herbal teas.

Of course, since K2 is a fat soluble vitamin, it is important to check with a doctor before taking, especially at high doses of if pregnant or nursing. I also recommend this book for learning more about Vitamin K supplementation and safety.

Food Sources of Vitamin K

Food sources of Vitamin K2Food sources of K1:

  • Kale
  • Dried Basil
  • Spring Onions/Scallions
  • Broccoli
  • Brussels Sprouts
  • Asparagus
  • Cabbage
  • Cucumbers
  • Prunes
  • Most greens

Food sources of K2:

Bottom Line

I believe that Vitamin K2 is an unspoken and vitally important nutrient and that widespread deficiency could be related to the rapid rise in health problems we see in modern society.

Those who have any of the health problems associated with K2 deficiency (listed above) might consider doing their own research on K2 and talking to a qualified doctor of practitioner to see if it would be beneficial for their specific cases.

Have you ever used Vitamin K2? Did you notice any benefit? Share below!

Katie Wells Avatar

About Katie Wells

Katie Wells, CTNC, MCHC, Founder of Wellness Mama and Co-founder of Wellnesse, has a background in research, journalism, and nutrition. As a mom of six, she turned to research and took health into her own hands to find answers to her health problems. is the culmination of her thousands of hours of research and all posts are medically reviewed and verified by the Wellness Mama research team. Katie is also the author of the bestselling books The Wellness Mama Cookbook and The Wellness Mama 5-Step Lifestyle Detox.


82 responses to “Vitamin K2: 9 Uses and Benefits”

  1. jeff bowles Avatar
    jeff bowles

    Hi there I once took 45 mg of vitamin k2 3 x a day for 3 months in an effort to decalcify my arteries..I never had them checked but I believe it worked a I used to drink lots of coffee and enjoyed i but a I got older it made me feel weird…after the 3 months of high dose k2 coffee mad me feel good again like when I was younger..So I shold have had MRI’s done before and after but too bad…


    I have been detected to have right carotid artery 70-80%blocked with calcification at base. I am aged 58 years vegetarian Indian male on blood thinning agents like statin , rosovas and olmart 40 and also vitamin B12 for the last 4 years when I suffered TIA. Plz do me favour if the calcium deposition in my artery can be cleared with supplements of vitamin K2 and if affirmative kindly suggest sources and amount of doses. Regards from

  3. Heidi Brownell Avatar
    Heidi Brownell

    Hi Wellness Mama,
    What oral vitamin k dosage schedule did you follow when giving to your babies? Trying to put together the best plan with all of the conflicting information out there!

  4. Jade Brunet Avatar
    Jade Brunet

    I wanted to know more about the importance of vitamin K2. I did not know that it was helpful in reducing cancer risks. Something to consider would be consulting with a doctor before taking the supplement to ensure that it will be beneficial.

  5. Elsha Avatar

    I make butter from raw cream so now I’m wondering how it seems to be only the butter that contains the vit k2 and not the cream??

  6. James Avatar

    I discovered K2 several years ago and have been taking 100 mcg daily since that time. And justifiably so as K2 moves calcium from the arteries into teeth and bone where it belongs. I also take D3 and magnesium but did not understand the synergism with K2 until I read the above article.

    My story starts in the 1950’s when dad died of a heart attack at age 39. I followed in succession with a heart attack at age 40, my brother at age 45 and my son at age 45. Very predictable in our family.

    My heart attack was followed by a quad by pass 23 years later. Recently my cardiologist recommended I have an angiogram 10 years post bypass as he had concerns about a less than robust stress test with imaging. BTW, I am now 73. The good news is my grafted veins are 100% clear. There was no bad news.

    I attribute this success to my supplements with K2 at the core and a diet similar to Mediterranean with a focus on organic kefir, grass fed butter and meats and wild seafood. I also avoid grains and sugar so my carb intake is rather low albeit, I consume large amounts of greens. I limit my fruit due to fructose.

    As my glucose levels are very low, I have been experimenting with a disaccharide known as Trehalose. My energy levels improved significantly and I find myself doing more physical work without being tired. Trehalose is converted to 100% glucose and is digested very slow for extended energy.

  7. Ed Darrell Avatar
    Ed Darrell

    A friend from my youth had a problem with bleeding, and his physician suggested eating the skin of an orange every day.

    What form of vitamin K is in orange skins, and is that a reasonable way to get it?

  8. Kate Grey Avatar
    Kate Grey

    Hi Kate!
    Thank you for all the information you’ve included. I was wondering if you could recommend a certain brand of K2 supplements. I know you mention Jarrow Formulas, but currently can’t afford to spend 12dollars on only 60capsules. Could you suggest different brands for different budgets?


  9. Laura Avatar

    I have been taking a D3 / K2 supplement combo for over a year now and while it does not appear to have any questionable ingredients, I do wish I could get the bulk of my D3 from the sun instead. I work long hours and rarely see the sun.

    What I have noticed is that not long after I started supplementing the D3, my sleep problems went away. I have taken magnesium citrate at bed time for three years but after reading your post on the benefit of trans-dermal absorption rather than ingestion, I will be making your magnesium oil right away! Thank you for this post.

  10. Ana Avatar

    Hi, I would like to hear your opinion about supplementing vitamin K for toddlers.
    I’ ve been looking for a supplement for kids that contains Vitamin K2 but I couldn’t find anything.
    From your experience, Is it safe to give the Vitamin K , Jarrow formulas, that you recommend, to a 3 year old?

  11. Petina Walsh Avatar
    Petina Walsh

    My understanding is that K2 is actually produced by colonic bacteria, not from fermented foods. Can you confirm?

  12. Anna Avatar

    I’m taking a 5,000 IU D3 supplement every 2 days as per the bottles instruction (although my Dr. recommended a 50,000 ID of D2) and a 90mg K2 supplement everyday. Is this a wise dosage? Should I increase either?

  13. Mar Avatar

    Hello- this is an old post so may not recieve this-please reply if possible:
    Please please can you just tell me more or less your advice on mg supplementation?
    I want to take Vit D3 ( winter months), K2, calcium and magnesium. I hear these are the essential 4 for optimum health but the balance needs to be perfect! i ordered a vitamin wt 5000mg D3 and 50 mcg K2 combined. (I will go less on Vit D3 in summer when i fet 15 min of sun)
    I just need to know the proper balance of supplementation for calcium and magnesium combined wt these?
    No one on any site seems to answer. I know everyone isn’t exact- but more or less there should be a minimum suggestion? All the mercola and health newsletters i get suggest these 4 supplements as key, but ALWAYS are very shady on how much?? Other than that the K2 should be about 5-10% amount of the D3. (5000mg D3/50mcg K2). I reallay am wary tomtake calciummand magnesium without knowimg how much to take?!
    Please share your opinion please. Dr Axe doesnt reply, I know you know him, if you can ask your expert friends?
    I am 54, used to be a runner more active, not so in 4 yrs, still in the menses tho fading out, fairly healthy, but overcoming operation so fairly sedentary lately, 20lbs overweight, trying to lose and “be healthy” eating organic and paleo a lot lately. If that helps any.
    THANK you!

    1. Wellness Mama Avatar

      I’m not a doctor and can’t give any specific medical advice. I personally get calcium from food and don’t take it supplementally and use a topical magnesium (this one) daily. I use about 20-25 sprays all over my body since I’ll only absorb what I need through skin…

    2. J.B. Avatar

      Check out Morley Robbins research at or on his Facebook group, “magnesium advocacy”. He does not recommend ANY calcium, or isolated D supplentation..instead, take Cod liver oil, magnesium and get sunshine, when available, to raise your D levels. Supplemental D can wreak havoc in your body, as it raises your active D levels to sometimes crazy high levels, when its your storage/active ratio that is most important. Also, there are certain forms of magnesium that are better at actually raising your RBC levels..

  14. Linny Avatar

    What exactly is a small amount of the powdered natto? Daily? Same portion for children?

  15. Afkar Avatar

    Is it safe to take one capsule of Jarrow k2 daily during the last few weeks of pregnancy? I am declining the vitamin K shot and want to make sure I have enough in my body to supply baby through breast milk. Thanks in advance!

  16. Bailey Avatar

    I am also curious about the Jarrow k2 during pregnancy. The capsules have evening primrose in them which, if I’m not mistaken, shouldn’t be taken until late in the 3rd trimester because it can induce labor. Wondering if there’s enough in the capsule to have an effect.
    Any tips on giving these to kids under 5??
    Thanks for the info!

  17. Bailey Avatar

    I am also curious about the Jarrow k2 during pregnancy. The capsules have evening primrose in them which, if I’m not mistaken, shouldn’t be taken until late in the 3rd trimester because it can induce labor. Wondering if there’s enough in the capsule to have an effect. Thanks for the info!

  18. Rachel Avatar

    Is the capsule form safe during pregnancy alongside a prenatal? Do you have any other natural remedies for varicose veins during pregnancy?

  19. Laura Avatar


    I was just curious when the various vein post can be expected? I’ve been researching horse chestnut and other remedies and would love to hear what you’ve discovered,


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