How Long Does Vitamin K2 MK-4 Remain Active in Your Body?

Updated: June 7, 2023

Lara Cover Photo

Lara Pizzorno is the author of “Your Bones: How You Can Prevent Osteoporosis and Have Strong Bones for Life – Naturally” and a member of the American Medical Writers Association with 29 years of experience specializing in bone health.

Recently we asked Lara if she would help provide a series of short, ongoing videos to help you (our customers and readers) stay up to date on the latest facts and science related to bone health.

In this latest video, Lara discusses how long vitamin K2 in the form of MK-4 stays active in your body…and you may be surprised at the answer. Watch the video below (or read the transcript provided) and let us know what you think in the comments. 🙂

Hello, my name is Lara Pizzorno and I’m the author of Your Bones. I’m here to share with you some information that I hope would help you to have healthier bones. In this video clip, we are going to talk about the dietary sources for vitamin K2. Specifically, we’ll be talking about the dietary sources for the short chain menaquinone, MK4, which is a version of K2 that only remains active in your body for about six hours.

The K2 story is a lot more complex than the vitamin K1 story, but I promise it’s not hard to understand. There’s just a lot more information than you find in relation to vitamin K1. And I will explain it fully, and I will repeat the key things you need to know many times.

So in this video, we are going to talk about:

  • Dietary sources for the short-life version of vitamin K2, which is called menaquinone 4 or MK4. And menaquinone 4 only remains active in your body for approximately six hours.

As I explained in one of the earlier videos in this series, if you eat a healthy diet that includes lots of vitamin K1, then your needs for vitamin K1 will be easily met. And if you eat so many leafy green vegetables, that you have extra K1 left over after it has been used to produce the clotting factors that you absolutely have to have so that you don’t bleed out from a paper cut; if you still have some vitamin K1 left over, then the extra K1 would go to your intestines where health promoting bacteria, in your intestines, can convert it into menaquinone 4 or MK4, the short life version of K2.

So in this sense, you can think of leafy greens as an indirect dietary source of vitamin K2.

But the food sources of vitamin K1, leafy greens, are not an adequate source of vitamin K2 for healthy bones because you really need to eat a lot of leafy greens to have enough vitamin K1 left over, so that some will go to the bacteria in your intestines and be converted into vitamin K2.

And, you have to have a healthy digestive tract that contains these healthy bacteria. And, the type of K2 that the bacteria produce, MK4, gets cleared out of our bodies very quickly. It’s only going to last for about six hours. And at best, your gut bacteria is only going to be producing a few micrograms of MK4. But for MK4 to have a beneficial impact on your bones, the research shows that what you need to have is 45 milligrams, not micrograms but milligrams. One milligram is 1,000 micrograms and during the studies, they gave women 15 milligrams or 15,000 micrograms every six to eight hours, three times a day – 45,000 micrograms a day is what they needed to have for beneficial effects on bones produced by MK4.

Your good bacteria, at best, is going to supply you with a few micrograms; it’s just nowhere near enough to do the job. And lastly, another reason why foods that are rich in K1 are not even a particularly great indirect source of K2 is that whether the vitamin K in leafy greens is going to be available for you depends not only on how much leafy greens you consume, but how well you absorb the vitamin K1 from these leafy greens. And vitamin K1 is very tightly bound to chloroplast membranes in plant cells, from which it is absorbed pretty ineffectively.

So if you want get the most K1 from the leafy greens that you eat, you want to try to always serve them dressed with a little oiloil-822618_640

I like some extra virgin oil, which has other benefits for you as well. 

Studies have shown that after eating spinach, a leafy green, circulating levels of vitamin K1 can be increased by at least three fold, if the greens are accompanied by a little vegetable oil. One other thing that you have to remember is as we discussed in an early video, when we were talking about vitamin K1, is that you want to make sure that the vegetable oils that you use are not hydrogenated, not even partially hydrogenated.

Unhydrogenated oil is required because when oil is hydrogenated or even partially hydrogenated, the vitamin K1 in it is changed from filoquinone into a form called dihydrofiloquinone, which doesn’t work anymore. It’s no longer capable of activating the vitamin K dependent proteins.

So be sure when you purchase your oils, that you are not getting even partially hydrogenated oil, and avoid hydrogenated or partially hydrogenated oils in processed foods.

Don’t eat them. They’re not going to help your bones.

We don’t need anywhere near as much of the longer lasting forms of vitamin K2, and the longer lasting forms are called the long chain menaquinones. And the form of those that are available as a supplement is MK7. But, in terms of getting MK7 or the long chain menaquinones from our diet, the foods that contain them, again, provide so little of the long chain menaquinones that to get enough K2 to help our bones you really need to take a supplement. And we would talk more about that later.

If you are taking AlgaeCal Plus and you are getting 100 micrograms of MK7, and this is the form that remains active in your body for the longest amount of time. Two to three days, unlike the MK4 form which gets cleared out of the body much more rapidly within six to eight hours. And if you regularly eat the foods that contain a tiny bit of vitamin K2 in the form of menaquinone or the other long chain menaquinones, they would supply you with a few more micrograms of K2 that last in your body and will serve you well.

We’ll talk more about the differences between MK4 and the MK7 forms of K2 later in the videos in which I would focus on the best sources of the different types of vitamin K2. In the next video, we’ll discuss: what are the best food sources of the long chain menaquinone forms of vitamin K2. I hope this video has been helpful for you and thank you for tuning in.


Geleijnse JM, Vermeer C, Grobbee DE, et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J Nutr. 2004 Nov;134(11):3100-5. PMID: 15514282

Photo via Pixabay

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  1. Kerry

    May 5, 2019 , 3:58 pm

    I have hemochromotosis and am finding it difficult to bleed during a phlebotomy. Could the Vit K2 I am taking be the cause of this and is my K2 too high and dangerous?

  2. Jenna AlgaeCal

    May 7, 2019 , 9:19 am

    Hi Kerry,

    Vitamin K2 promotes healthy blood clotting and does not cause excess blood clot formation! However, it’s best to speak with your doctor who has a complete understanding of your medical history to determine if vitamin K2 supplementation is right for you — and the optimal dose.

    – Jenna @ AlgaeCal

  3. Gerhard

    May 15, 2020 , 5:13 pm

    Actually, vitamin K1 promotes blood clotting…….

  4. Blaire AlgaeCal

    May 19, 2020 , 2:08 pm

    Sorry for any confusion, Gerhard! Both vitamin K2 and K1 assist with blood clotting ?

    Let us know if you have any questions!

    – Blaire @ AlgaeCal

  5. Kerry

    June 6, 2020 , 7:08 am


    Me and my daughter 14 is taking d3 1000mcg with k2 100mcg . How much extra mk7 do we need ?

  6. Blaire AlgaeCal

    June 8, 2020 , 12:44 pm

    Hi Kerry,

    Thanks for reaching out!

    100 mcg of vitamin K2 should be sufficient with that amount of vitamin D3 for yourself. However, we recommend discussing any vitamin intake for your daughter with her doctor ❤️

    – Blaire @ AlgaeCal

  7. Wichai

    June 14, 2021 , 5:43 am

    My friends have told me to take d3 5000iu and k2 mk7 100 mcg, are these dangerous? How many days should I take a week? Is calcium carbonate still needed?

    Thank you in advance for your answers

    Best regards,

  8. Megan AlgaeCal

    June 17, 2021 , 8:49 am

    Hi Wichai!

    Vitamin D3 requirements vary greatly from person to person. The best way to know how much you need is to have a blood test done. You can learn more about this here. The amount of vitamin K2 recommended for you will differ based on how much vitamin D3 you take.

    Regarding calcium, we recommend looking for a plant-based calcium that provides all the bone-healthy nutrients, including vitamin D3, vitamin K2, etc. If you’re interested, AlgaeCal includes all of these and more! Feel free to learn more about AlgaeCal here or by giving us a call at 1-800-820-0184 (USA & Canada toll free).

    Hope this helps!

    -Megan @ AlgaeCal

  9. mimi hamil

    August 2, 2021 , 6:44 am

    Hi Kerry,
    I have VTE from Covid and Dr prescribed blood thinner. Now they reduce from 5 mg to 3 mg and 1day take and 1 day off.
    I like to have vegies. May I ask, how long will Vitamin K stay in my body.
    Let said I take the blood thinner at night on Sunday. and the Monday night I won’t take… so can I eat vegie spinach on Monday – all day and Tus i won’t eat them because I will need to take the medicine on Tuesday night.
    Thank you,

  10. Megan AlgaeCal

    August 4, 2021 , 9:01 am

    Hi Mimi,

    It’s best to check in with your doctor regarding their recommendations for you. They may advise you to avoid vitamin K or to simply make sure you have a consistent intake of vitamin K. As they have a record of your overall medical history, they’ll be able to best help. ❤️

    – Megan @ AlgaeCal

  11. Alvina

    February 22, 2023 , 7:36 am

    Can you send these videos to me?

  12. Manja

    February 22, 2023 , 11:51 am

    Hi Alvina, thank you for your interest in our blog post on Vitamin K2! I’m sorry that we are not able to send the videos included in our articles and we appreciate your understanding. If you wish to revisit the article in the future, may I suggest bookmarking the page in your browser? Let us know if there’s anything else we can assist you with.

    – Manja @ AlgaeCal

  13. Sandra

    April 24, 2023 , 1:44 pm

    Great article, I didn’t know about the 2 types. I’ve just ordered my first Bone Builder pk.

  14. Brianne AlgaeCal

    April 25, 2023 , 10:13 am

    So great to hear you’ve gotten started with AlgaeCal, Sandra! Have you joined the AlgaeCal Community yet? It’s a supportive space for AlgaeCal
    customers to learn and grow together! We’d love for you to join HERE! 🙂

    – Brianne @ AlgaeCal

  15. Naima Jamil

    April 25, 2023 , 11:48 am

    Hello Lara. I watched your video and very sorry to say your described information on how the Vitamin K2 MK-4 is synthesized in the human body, is incorrect. MK-4 is the only form of Vitamin K2 synthesized without fermentation, with the help of gut bacteria. Instead MK-4 is synthesized from Vitamin K1 and combined with another endogenius molecule named GG(GeranylGeraniol) in 24/25 organs of the human body. All other K2s are synthesized through the fermentation process. Please listen to Dr Barrie Tan’s podcasts on how K2 MK-4 is formed from K1.

  16. Lara Pizzorno, MDiv, MA, LMT

    April 28, 2023 , 3:16 pm

    Hi Naima, thank you for bringing the need to update this video to my attention!

    The video you saw was taped in 2014, at which time, the information provided was a correct summation of current research. The accepted understanding of MK-4 synthesis then was that MK-4 was derived primarily in the intestines from K1 with the help of probiotic bacteria. 

Here’s one example and quite a few additional citations stating this view: 
“Apart from the dietary intake sources, MKs are mainly synthesized by gut microbiota, predominantly in the ileum (58). MKs are abundant in the human gut, and the concentrations of different MK forms within the intestine show considerable intraindividual and interindividual variations related to heterogeneity in the intestinal microbiome composition (59). Bacteria can release MKs in lipid-soluble (60) or other forms of complexes, such as short-chain quinones (61)…” (As I believe you know, MK-4 is the shortest chain menaquinone.) 

The gene encoding UBIAD1, the biosynthetic enzyme for MK-4, was just identified in 2014, and that discovery initiated the research investigating UBIAD1’s production of MK-4 in humans, which Dr. Tan is now talking about in his podcasts.

    Since 2014, we’ve learned that:
    “In animals and human beings, MK-4 is catabolized from K1 with K3 as an intermediate with UbiA prenyltransferase domain-containing protein 1 (UBIAD1) (54), and partially from long-chain MKs in extrahepatic tissues, for example, salivary gland, brain, pancreas, reproductive organs, kidney, and fat (1)…The prenylation process seems to happen independently from intestinal bacteria (56, 57). ” 

We now know that while all other MKs are synthesized by bacteria, some of which are present in the human microbiome, MK-4 is an atypical MK that can be synthesized in vivo given a suitable naphthoquinone precursor such as menadione or K1.
    MK4 is synthesized in the mitochondria of animal tissues from phylloquinone (K1) via the following process. Briefly, the phytyl sidechain of K1 is removed by a still unknown enzyme, liberating menadione as an intermediate. Then UBIAD1 (a transferase enzyme) transfers the geranylgeranyl group from geranylgeranyl pyrophosphate to menadione to form MK4. So that’s where geranylgeraniol (GG) comes in.

    Geranylgeraniol (GG) is the initial inactive form of geranylgeranyl pyrophosphate. It’s produced in the mevalonate pathway (the same biochemical pathway via which we produce cholesterol), is converted to “activate” form, geranylgeranyl pyrophosphate (GGPP), and used in quite a few life essential processes: protein synthesis and posttranslational modification (protein prenylation), and as a building block in the production of testosterone, vitamin E and MK-4 from K1.

    While we now know that humans are capable of producing MK-4 in quite a few tissues, providing optimal amounts of this critical nutrient is, unfortunately, not so happily straightforward for several reasons: 

UBIAD1 SNPs that adversely affect the function of this enzyme are not uncommon, specifically the G186R mutation. 

Another problem is the all too common use of the bisphosphonates and statin drugs, both of which interfere with the mevalonate pathway and thus the production of GG. 

Producing sufficient MK-4 requires a constant supply of excess K1 since (per Ames’ groundbreaking paper on triage theory (which came out in 2009), K1 will first be used to activate clotting factors and only excess K1 will be available for MK-4 synthesis. You may remember, the MK-4 form of K2 clears typically in 6 hours, possibly in 8-10 if your genetic inheritance includes slower versions of the enzymes that clear vitamin K, but again, far from rarely seen SNPs result in increased vitamin K clearance. 

Very few people now consume large amounts of leafy greens or unrefined vegetable oils containing phylloquinone, and certainly do not do so every 6-8 hours. Not only do we not ingest the necessary amounts of leafy greens, but the primary source of K1 in the modern diet is processed vegetable oils, and the form of K1 found in processed oils is dihydrophylloquinone, a form that is not converted to MK-4, which is why its intake is associated with low BMD and CVD.

    Booth et al. examined the bioavailability of dihydro-K1 in humans, in which, following a 15-day depletion of dietary vitamin K, subjects were fed 200 μg/day of either K1 or dihydro-K1. They found that dihydro-K1 had a low biological activity in hepatic vitamin K-dependent clotting proteins (PIVKA-II were produced; these are inactive under-γ-carboxylated forms of vitamin K-dependent clotting factors) and no biological activity in an extrahepatic vitamin K-dependent protein (osteocalcin). In the Booth et al. study, the plasma K1 concentration after the administration of K1 was far higher than after administration of dihydro-K1. In rats, dihydro-K1 was well absorbed and its concentrations in the serum were much higher than that of K1. In humans, however, dihydro-K1 is poorly absorbed and produces low to no biological activity. 

For all these reasons, despite the fact that I do consume unrefined organic vegetable oils and at least 5 cups of organically grown leafy greens – picked fresh from our own garden daily, I continue to recommend supplemental MK-7 and personally rely on its use to safeguard the health of my bones and cardiovascular system.

    Lastly, regarding Dr. Tan, I know Barrie personally and respect him greatly. Joe (Dr. Pizzorno) and I just saw him and his wife, Elizabeth, at the IHS conference in NYC in February. We exchanged books – we all did book signings at this conference – so I have a copy of his latest, The Truth about Vitamin E, in which he sums up ground-breaking research on the tocotrienols, especially delta-tocotrienol. I highly recommend you get a copy and read this, if you have not already done so and consider adding delta-tocotrienol to your bone health protocol.

  17. Cindy Johnston

    May 3, 2023 , 7:36 am

    Lara explains the differences between the MK levels so clearly, that I, as a non-scientist, can understand. I will still eat leafy green vegetables, but also continue FOREVER, my AlgaeCal supplements.

  18. Brianne AlgaeCal

    May 3, 2023 , 2:41 pm

    So very happy you found this information easy to understand, Cindy! Thank you for the positive feedback! 🙂

    – Brianne @ AlgaeCal

  19. Marilyn McGuire

    May 3, 2023 , 8:36 am

    This was very educational. I knew nothing about MK 4 or 7 before.

  20. Yoori AlgaeCal

    May 3, 2023 , 6:12 pm

    We are happy to hear that the article was informative, Marilyn!

    – Yoori @ AlgaeCal

  21. Barbara Greenstein

    May 3, 2023 , 12:01 pm

    IK can be very confusing. Thanks for explaining the difference.

  22. Norma King

    May 3, 2023 , 12:16 pm

    I like the idea of leafy greens with good oil.

  23. Luisa Saffiotti

    May 3, 2023 , 12:25 pm

    I really appreciated Lara Pizzorno’s explanation of the mecahnisms of K1 and K2 absorption and storage. I was delighted to learn that eating greens with olive oil improves K1 absorption—that combination is a daily part of my diet !
    Also great to know that Algae Cal Plus includes the necessary daily dose of MK7.

  24. Cheryl D

    May 3, 2023 , 1:18 pm

    Appreciate the Vitamin K explanations. I did not realize the differences and will watch for more of the AlgaeCal videos.

  25. Peggy

    May 3, 2023 , 1:53 pm

    I was taking a D3 5000iu supplement. After being on AlgaeCal Plus for 3 months my blood work showed the Vitamin D level high so my Dr. said to stop the D3 supplement. I also no longer take a Vitamin K supplement. I eat more leafy greens with oil and balsamic vinegar.

  26. Samantha AlgaeCal

    May 5, 2023 , 10:32 am

    Peggy, the 1600 IU of vitamin D included in the daily dosage of AlgaeCal Plus is sufficient for maintaining optimal blood levels of vitamin D. My understanding is that the optimal range of vitamin D blood level is in between 50-80 ng/mL. Once you are back within normal range, you may not need additional supplemental vitamin D3! Additionally, our AlgaeCal Plus contains a clinical dosage of 100mcg of Vitamin K2 and if you are taking less than 5000 IU of Vitamin D3 daily, this amount would be sufficient.
    I’m happy to hear you’re eating more leafy greens, as they are nutritious foods that contain a great amount of calcium and some vitamin K – both of which are good for bone health! Keep it up. 🙂

    – Sam @ AlgaeCal

  27. Joyce Gonzales

    May 3, 2023 , 3:00 pm

    The lady talked about vitamin k1 and vitamin k2 which our bodies need. Good to know about spinach. I love spinach. And we should take a suppliment AlgaeCal would be great. I usually use olive oil especially in cucumber salad.

  28. Kary Piper

    May 3, 2023 , 3:02 pm

    I appreciate that there is so much detailed and scientific information given.

  29. Elissa Kerhulas

    May 3, 2023 , 5:17 pm

    This is so helpful. I’ve been aware of the benefits of K2, but never knew the differences of sources. I’ve been taking Algae Cal’s Bone Builder program and feel confident I’m getting the right MK7 to feed my bones. Thank you.

  30. Sherry J Vandonkelaar

    May 3, 2023 , 8:01 pm

    I didn’t know that I needed oil with my greens. Thanks for that information!

  31. Rashidah El-Amin

    May 4, 2023 , 4:13 am

    I currently take a tablespoon of organic extra virgin olive oil daily to help with my cholesterol and always add a tablespoon to my raw veggies never knowing I was adding xtra protection for vitamin K2.

  32. Karen

    May 4, 2023 , 9:23 am

    Thank you for this informative video and article! So glad I am getting the form of K2 I need from AlgaeCal!

  33. Sheila Green

    May 4, 2023 , 12:30 pm


  34. Rebecca (Becky) Mikla

    May 5, 2023 , 9:28 am

    What great information in the video and article.

  35. Cathy

    May 5, 2023 , 9:01 pm

    I remember when I was a kid that Mom always had Vitamin K shots. I was too young to know what they were for. Happy to know I don’t need shots and can get the right kind of K I need.

  36. Marg

    May 6, 2023 , 5:25 am

    Thanks for sharing all the Vitamin K2 info. Since I don’t eat natto, I feel happy that the correct amount of K2 MK7 is in Algaecal. 🙂

  37. Brianne AlgaeCal

    May 9, 2023 , 7:30 am

    It’s our pleasure, Marg, and we are so happy that you are feeling confident with your AlgaeCal! Please never hesitate to reach out if there is anything we can do to support you! 🙂

    – Brianne @ AlgaeCal

  38. Kandy Riave Hutman

    May 8, 2023 , 4:32 am

    This makes me even more grateful for AlgaeCal Plus

  39. L Miller

    May 8, 2023 , 10:08 am

    Good information. Vitamin K is relatively new to me. I’m glad to hear the details.

  40. Melanie

    May 14, 2023 , 5:49 am

    What great information on K1 and K2. I am so appreciative of Lara for her information. Clearly, the microbiome is an amazing ‘brain’. I am off to get the foods and supplements needed to help my bone health.

  41. Chelsea Dugas

    May 15, 2023 , 11:09 am

    So happy to hear you are jumping into action, Melanie! Thanks for sharing and let us know if you have any questions! 🙂

    – Chelsea @ AlgaeCal

This article features advice from our industry experts to give you the best possible info through cutting-edge research.

Lara Pizzorno
MDiv, MA, LMT - Best-selling author of Healthy Bones Healthy You! and Your Bones; Editor of Longevity Medicine Review, and Senior Medical Editor for Integrative Medicine Advisors.,
Dr. Liz Lipski
PhD, CNS, FACN, IFMP, BCHN, LDN - Professor and Director of Academic Development, Nutrition programs in Clinical Nutrition at Maryland University of Integrative Health.,
Dr. Loren Fishman
MD, B.Phil.,(oxon.) - Medical Director of Manhattan Physical Medicine & Rehabilitation and Founder of the Yoga Injury Prevention Website.,
Prof. Didier Hans
PHD, MBA - Head of Research & Development Center of Bone Diseases, Lausanne University Hospital CHUV, Switzerland,