By Dr. Joseph Mercola, a physician trained in both traditional and natural medicine who provides up-to-date natural health information
Shared by Nutrition Breakthroughs,
maker of the effective calcium and magnesium based sleep aid Sleep Minerals II
While the importance of vitamin D has become more fully appreciated, another vitamin that is just as important as vitamin D, vitamin K2, needs wider recognition. It’s a fat-soluble vitamin most well known for its role in blood clotting.
However, there are two primary kinds of vitamin K, and they serve very different functions. Vitamin K1 is the primary form of vitamin K responsible for blood clotting, whereas vitamin K2 is essential for bone strength, the health of arteries and blood vessels, and plays a role in other biological processes as well, including tissue renewal and cell growth.
In the 2014 paper, “Vitamin K: An old vitamin in a new perspective,” vitamin D expert Dr. Michael Holick and co-authors review the history of vitamin K and its many benefits, including its significance for skeletal and cardiovascular health. They also discuss important drug interactions.
Vitamins K1 and K2 are Not Interchangeable
The difference between vitamins K1 and K2 was first established in the Rotterdam Study, published in 2004. A variety of foods were measured for vitamin K content, and vitamin K1 was found to be present in high amounts in green leafy vegetables, such as spinach, kale, broccoli, and cabbage.
Vitamin K2, on the other hand, is only present in fermented foods. It’s produced by certain bacteria during the fermentation process. Interestingly, while the K1 in vegetables is poorly absorbed, virtually all of the K2 in fermented foods is readily available to your body.
Examples of foods high in vitamin K2 include raw dairy products such as certain cheeses, raw butter, and kefir, as well as natto (a fermented soy product) and fermented vegetables like sauerkraut.
However, not every strain of bacteria makes K2, so not all fermented foods will contain it. For example, pasteurized dairy and products from confined animal feeding operations (CAFOs) are NOT high in K2 and should be avoided. Only grass-fed animals (not grain fed) will develop naturally high K2 levels.
Most commercial yogurts are virtually devoid of vitamin K2, and while certain types of cheeses, such as Gouda, Brie, and Edam are high in K2, others are not. It really depends on the specific bacteria present during the fermentation.
One of the best sources I’ve found is to ferment your own vegetables using a special starter culture designed with bacterial strains that produce vitamin K2.
My research team found we could get 400 to 500 micrograms (mcg) of vitamin K2 in a two-ounce serving of fermented vegetables using such a starter culture, which is a clinically therapeutic dose.
If you want to learn more about making your own fermented vegetables with a starter culture, you can watch the video at Mercola.com.
Sub-Categories of Vitamin K2
Vitamin K2 (a fat-soluble vitamin) can be broken into two additional categories, called:
- MK-4 (menaquinone-4), a short-chain form (a type of fat) of vitamin K2 found in butter, egg yolks, and animal-based foods. Short chain fats are often liquid at room temperature.
Avoid this in supplemental form, as it’s only available in synthetic form. MK-4 also has a very short biological half-life (the time it takes to reduce the amount of a supplement by one-half in the body) — about one hour— making it a poor candidate as a dietary supplement.
- MK-7 (menaquinone-7), longer-chain forms. (A longer chain form has more chains of carbon atoms). (These are fats that are solid at room temperature) and found in fermented foods. There’s a variety of these long-chain forms but the most common one is MK-7.
This is the one you’ll want to look for in supplements, as this form is extracted from real food, specifically natto, a fermented soy product. You could actually get loads of MK-7 from consuming natto, which is relatively inexpensive and available in most Asian food markets.
The MK-7, which forms in the fermentation process, has two major advantages. It stays in your body longer, and has a longer half-life, which means you can just take it once a day in very convenient dosing.
Health Effects of Vitamin K2 Deficiency
Vitamin K2 is an important adjunct to vitamin D, without which vitamin D cannot work properly. K2’s biological action is also impaired by a lack of vitamin D, so you really need to consider these two nutrients together.
This means that if you take high doses of oral vitamin D you need to remember to also increase your vitamin K2 intake from either food or a MK-7 supplement. Failing to do so could cause harm, as without K2, your body will not be able to complete the transport of calcium into the proper areas, and arterial calcification could set in.
If you get your vitamin D primarily from sun exposure then this issue is largely circumvented, as your body is then able to regulate its vitamin D production. You simply cannot overdose on vitamin D from sun exposure.
Vitamins D and K2 also work synergistically with magnesium and calcium, so this quartet should ideally be taken in combination. Unfortunately, most people are deficient in both vitamins D and K, and magnesium insufficiency is also common.
At least 50 percent of the general population is at risk of vitamin D deficiency and insufficiency, and as many as 97 percent may be lacking in vitamin K2. This could very well be due to the fact that we stopped eating fermented foods with the advent of refrigeration and other food processing techniques.
While you likely get sufficient amounts of vitamin K from your diet to maintain adequate blood clotting, you’re probably not getting enough to protect you from a variety of other health problems that are more specifically associated with vitamin K2, such as:
Beware: Statins May Deplete Vitamin K2
Statins are a group of drugs that act to reduce levels of fats, including cholesterol, in the blood. Besides a vitamin K2-poor diet, certain drugs may affect your vitamin K2 status. Research published in the Journal of the American College of Cardiology suggests statin drugs may increase calcification in the arteries, and other research shows that statins deplete vitamin K2.
You may be aware that statin users need to take CoQ10 (or ubiquinol) as the drug depletes this nutrient, but they may also need vitamin K2 in order to avoid the cardiovascular risks associated with statins.
Why Vitamin K Is Critical for Cardiovascular Health
In the 1980s, it was discovered that vitamin K is needed to activate the protein osteocalcin, which is found in your bone. A decade or so later, another vitamin K-dependent protein was discovered: matrix Gla protein (MGP), found in your vascular (heart) system.
Without vitamin K, these and other vitamin K-dependent proteins remain inactivated, and cannot perform their biological functions. Another important finding was that MGP strongly inhibits calcification. When MGP remains inactivated, you end up with serious arterial calcifications, and this is why vitamin K is so crucial for cardiovascular health. Evidence suggests vitamin K can even reverse arterial calcification induced by vitamin K deficiency.
Vitamin K2 also helps prevent arterial calcification by shuttling calcium away from areas where it shouldn’t be (in the lining of your blood vessels) to where it’s really needed (such as in your bone). In the Rotterdam Study, which ran for 10 years, those who consumed the greatest amounts of K2 had the lowest risk of cardiovascular disease, cardiovascular calcification, and the lowest chance of dying from cardiovascular disease.
People who consumed 45 mcg of K2 daily lived seven years longer than people getting 12 mcg per day. This was a profound discovery, because such a correlation did not exist for K1 intake. In a subsequent trial called the Prospect Study, 16,000 people were followed for 10 years. Here, they found that each additional 10 mcg of K2 in the diet resulted in nine percent fewer cardiac events.
More recently, a study published in a medical journal on circulation, found that MK-7 supplementation improved arterial stiffness in otherwise healthy postmenopausal women. This study has been lauded as significant because while previous studies have only been able to show an association, this is the first to confirm that long-term use of vitamin K2 in the form of MK-7 does result in improved cardiovascular health.
Vitamin K2 Is Crucial for Osteoporosis Prevention
As mentioned, vitamin K2 also plays a crucial role in bone health, and may be critical for the prevention of osteoporosis. Osteocalcin is a protein produced by your osteoblasts (cells responsible for bone formation), and is utilized within the bone as an integral part of the bone-forming process. However, osteocalcin must be “carboxylated” (take part in a salt-like reaction) before it can be effective. Vitamin K functions as a cofactor for the enzyme that catalyzes (allows) the carboxylation of osteocalcin.
A number of Japanese trials have shown that vitamin K2 completely reverses bone loss and in some cases even increases bone mass in people with osteoporosis. The pooled evidence of seven Japanese trials also show that vitamin K2 supplementation produces a 60 percent reduction in vertebral fractures and an 80 percent reduction in hip and other non-vertebral fractures.
A recent Chinese meta-analysis of 19 randomized controlled trials found that vitamin K2 supplementation significantly improved vertebral bone density in postmenopausal women, and reduced the risk of bone fractures.
Another three-year long placebo-controlled study done in the Netherlands found that postmenopausal women taking 180 mcg of MK-7 per day increased their bone strength and saw a decrease in the rate of age-related bone mineral decline and reduced loss of bone density, compared to those taking a placebo.
Vitamin K2 Is Also Important for Healthy Pregnancy, Cancer Prevention, and More
Vitamin K2 also plays an important role throughout pregnancy and during breastfeeding for the healthy growth of the child. Not only does it affect the development of both primary and adult teeth; it also helps develop proper facial form and strong bones. (During childhood, vitamin K2 helps prevent cavities.) It may be particularly important during the third trimester, as most women’s levels tend to drop at that time, indicating there’s an additional drain on the system toward the end of the pregnancy.
Since there are no reported cases of overdose of vitamin K2, and appears to have no toxicity issues, it may be prudent to double or even triple your intake while pregnant. Cancer prevention is another health benefit of vitamin K2. The 2010 European Prospective Investigation into Cancer and Nutrition (EPIC) study found that high intake of vitamin K2 — not K1 — leads to reduced cancer risk, as well as a 30 percent lower risk of dying from cancer.
The evidence also suggests vitamin K2 may reduce the risk for a type of lymphoma (cancer of the lymph nodes). Mayo Clinic researchers discovered that people with the highest intake of vitamin K2 had a 45 percent lower risk for this type of cancer, compared to those with the lowest vitamin K2 intake. They attribute this effect to vitamin K2’s ability to inhibit inflammatory cytokines, which are related to this type of lymphoma, and its role the life cycle of your cells. Researchers are also looking into other health benefits.
- Vitamin K2 has been shown to improve insulin sensitivity; people who get the most vitamin K2 from their foods are about 20 percent less likely to develop type 2 diabetes
- One 2012 study found vitamin K2 has the potential to improve disease activity in those with rheumatoid arthritis (RA)
- Another study, found that vitamin K2 serves as an electron carrier for the energy producing portion of our cells, thereby helping maintain normal ATP production (ATP is the energy factory in our cells) and preventing dysfunction, such as that found in Parkinson’s disease
- According to Dr. Holick’s paper, vitamin K2 has anti-inflammatory,
anti-oxidative, and anticarcinogenic properties, and in addition to cancer and diabetes, MK-7 in particular may also offer benefits for age-related macular degeneration in the eyes.
Are You Getting Enough Vitamin K?
Clearly, you want both vitamin K1 and K2, but you’re virtually guaranteed to not get enough K2 from your diet unless you eat the proper fermented foods. Dietary sources of vitamin K1 include:
As for a clinically useful dosage of vitamin K2, some studies — including the Rotterdam study — have shown as little as 45 micrograms (mcg) per day is sufficient. As a general guideline, I recommend getting around 150 mcg of vitamin K2 per day. Others recommend slightly higher amounts; upwards of 180 to 200 mcg. You can obtain healthy amounts (about 200 mcg) of K2 by eating 15 grams (half an ounce) of natto each day, or fermented vegetables. If you fermented them using a starter culture designed with vitamin K2-producing bacteria, one ounce will give you about 200 to 250 mcgs.
If you opt for a vitamin K2 supplement, make sure it’s MK-7. Also remember to take it with fat since it’s fat-soluble and won’t be absorbed otherwise. Fortunately, you don’t need to worry about overdosing on K2, as it appears to be completely non-toxic. People have been given a thousand-fold “overdose” over the course of three years, showing no adverse reactions (i.e., no increased clotting tendencies).
That said, people who are taking vitamin K antagonists, i.e. drugs that reduce blood clotting by reducing the action of vitamin K, are advised to avoid MK-7 supplements. As a last tip, keep in mind that vitamin K2 may not necessarily make you “feel better” per se. Its internal workings are such that you’re not likely to feel the difference physically. Compliance can therefore be a problem, as people are more likely to take something that has a noticeable effect. This may not happen with vitamin K2, but that certainly does not mean it’s not doing anything.
This article on vitamin K2 benefits is shared with you by Nutrition Breakthroughs, maker of the original calcium and magnesium based natural sleep aid Sleep Minerals II, and Joints and More, the natural remedy for joint relief, aches and pains, stronger hair and nails, and more energy.
Fermented foods like cheese, sauerkraut, and natto (a soybean product) are also high in K2. The only plant sources of K2 are these fermented foods, with the highest amount in natto; unless you regularly eat this, relying on animal products for K2 will be easier for most people on western diets.Do all fermented foods have vitamin K2? ›
Vitamin K2 is mainly present in fermented food such as cheese and natto (fermented soybeans), but gut microbiota are also able to synthesize vitamin K2 . One exception, menaquinone-4 (MK-4), is formed in humans and animals by tissue-specific conversion of PK and/or menadione .How much vitamin K2 is in fermented food? ›
The highest source of dietary Vitamin K2 is currently found in a traditional Japanese fermented soy bean dish called Natto, containing a whopping 850mcg of Vitamin K2 per serving.How much sauerkraut per day for K2? ›
In another, women reduced their risk of heart disease by 9% for every 10 mcg of vitamin K2 they consumed per day ( 75 ). For reference, 1 cup of sauerkraut contains about 6.6 mcg of vitamin K2 ( 76 ).Does store bought sauerkraut have vitamin K2? ›
Sauerkraut is fermented cabbage with a distinctive sour flavor. Like with natto, this fermentation process offers many health benefits, like promoting good gut health and boosting immunity. With 2.75 micrograms per half-cup, sauerkraut is also a great source of vitamin K2.
Some commercial sauerkrauts contain as many as 28 different strains of lactic acid bacteria. Sauerkraut is a great source of vitamin K2, containing 6 micrograms (mcg) of the vitamin per cup. Other sources of vitamin K2 include natto — fermented soybeans — as well as chicken, eggs, and some hard cheeses.Does vitamin K2 remove plaque from arteries? ›
Optimal Vitamin K2 intake is crucial to avoid the calcium plaque buildup of atherosclerosis, thus keeping the risk and rate of calcification as low as possible. Matrix GLA protein (MGP)—found in the tissues of the heart, kidneys, and lungs—plays a dominant role in vascular calcium metabolism.Which vegetable has the most vitamin K2? ›
- dark leafy green vegetables, such as spinach, kale, and collards.
- vegetable oils.
A daily K2 dosage of 75–120 µg, a range encompassing the recommended dose in many countries, provides adequate osteocalcin activation. A dose of 375 µg per day, however, may provide more efficient osteocalcin activation and, therefore, better utilisation of available calcium for bone building.What is the best form of K2? ›
There are two main types of Vitamin K2 available for supplementation: MK-4 and MK-7. While both are forms of vitamin K2, MK-7 has been shown to be more effective than MK-4 at producing osteocaclin and reducing overall cardiovascular risk.
Full-fat kefir is an excellent source of vitamin K2, as well as calcium, both of which are beneficial to bone health and reducing the risk of developing osteoporosis.What happens if you have too much vitamin K2? ›
Vitamin K toxicity is extremely rare. The only reported toxicity comes from menadione, which has no use in humans. Its toxicity is thought to be associated with its water-soluble properties. When toxicity does occur, it manifests with signs of jaundice, hyperbilirubinemia, hemolytic anemia, and kernicterus in infants.How many eggs should I eat daily for K2? ›
One dozen eggs a day from caged hens won't supply enough K2 for your daily requirement, whereas two to four eggs a day from pasture-raised hens may provide adequate K2.How long does it take for sauerkraut to heal gut? ›
When I did the sauerkraut protocol, it took me about 6 weeks to get through step 3 and about 2 months to get through all the steps. But everyone is different. Probiotics crowd out bad bacteria; anti-bacterials kill bad bacteria. To eradicate stubborn bad gut bacteria, try taking some anti-bacterial herbs.What foods contain the most K2? ›
Vitamin K2 is only found in animal foods and certain fermented dishes. Small amounts are also produced by your gut bacteria ( 10 ). Natto, a Japanese dish made from fermented soybeans, is one of the best sources of vitamin K2. Other good sources include meat, liver, and cheese ( 11 ).Are pickles high in vitamin K2? ›
The pickling or fermenting process that helps create pickles or slaws like kimchi and sauerkraut and makes them rich sources of probiotics also produces menaquinones, vitamin K2. One cup of pickled cucumbers contains 130 mcg (109% DV) of vitamin K.Does olive oil have vitamin K2? ›
ALL YOU NEED TO KNOW ABOUT VITAMIN K.
|Food||μg per serving|
|Blueberries, raw (1 cup)||14|
|Chicken breast, cooked (85g)||13|
|Canola oil (1 Tbsp)||10|
|Olive oil (1 Tbsp)||8|
Sauerkraut contains far more lactobacillus than yogurt, making it a superior source of this probiotic. Two ounces of homemade sauerkraut has more probiotics than 100 probiotic capsules. Store-bought sauerkraut is often treated with preservatives, meaning it does not offer the same health effects as homemade sauerkraut.Who should not eat fermented foods? ›
- People who are already bloated. Fermented foods are probiotics (ie. ...
- People who are intolerant to histamines. Histamine is a compound that is produced by the body and found in fermented foods. ...
- People who have a compromised immune system.
As mentioned earlier, ACV contains vitamin K2, which is helping in treating bronchial asthma.
Sources of Vitamin K2
Natto, a fermented soy product, contains the greatest amount. Other plant-based sources include sauerkraut, tempeh, and kombucha, but their K2 content is inconsistent and will depend on the method of production.
In the groups receiving high-dose vitamin K1 or K2 (MK-4), not only was there no further arterial calcium accumulation, there was a 37% reduction of previously accumulated arterial calcification after six weeks. After 12 weeks, there was a 53% reduction in accumulated arterial calcium deposits.Can K2 reverse arterial calcification? ›
Vitamin K-2 acts to prevent calcification of arteries, and it can reverse calcification after it happens. Secondly, Vitamin K-2 also uniquely activates a hormone in our bones named osteocalcin. This activation step is necessary and essential for the transfer of circulating calcium out of plasma into the bone matrix.What herb dissolves artery plaque? ›
- Alpha-Linolenic Acid (ALA)
- American Ginseng.
- Asian Ginseng.
- Carnitine (L-Carnitine)
Avocados: Avocados are high in vitamin K, although the amount varies from avocado to avocado. Vitamin K content in guacamole can varies even more.What does vitamin K2 do for hair? ›
Vitamin K2, to be specific, is crucial to preventing scalp calcification, which is when calcium builds on the scalp and prevents hair growth. Vitamin K2 helps us regulate our calcium intake and maintain a healthy scalp.Does broccoli have vitamin K2? ›
Vitamin K predominantly, naturally, presents in the form of phylloquinone (vitamin K1) and menaquinone (vitamin K2). Primarily, phylloquinone is present in green leafy vegetables such as spinach, kale, broccoli, and certain vegetable oils .Can K2 reverse osteoporosis? ›
Some, but not all research, demonstrates that people with osteoporosis can use Vitamin K2 to improve both bone density and bone strength. Vitamin K2 is more effective than Vitamin K1 for improving bone health. The main sources of Vitamin K2 are animal products and fermented foods.How much vitamin K2 to unclog arteries? ›
A subgroup analysis of the study observed that vitamin K2 MK-7 (720 µg/day) and D (25 µg/day) supplementation for two years helped slow the progression of coronary plaque development in individuals at high risk of developing coronary artery calcification with no prior identified ischemic heart disease.What is the best way to absorb vitamin K2? ›
Take your Vitamin K2 supplement with your dinner that includes dietary fat or at bedtime, 8 to 12 hours after you take your Vitamin D3. Most people take their D3 with breakfast and K2 at dinner time and this seems sensible, as some research shows that D3 is more effective if not taken at the same time as K2.
Thanks to its powerful antioxidant properties, vitamin K might be the key to more youthful and radiant skin. It's been shown to reduce visible signs of skin aging, combat dark circles, soothe inflammation, and accelerate wound healing.What herbs are high in vitamin K2? ›
A 1/4-cup serving of fresh parsley contains the most vitamin K with 246 micrograms. Dried parsley is also a good source of vitamin K with 21.8 micrograms per tablespoon. A tablespoon of dried marjoram provides 10.6 micrograms of vitamin K. Dill, bay leaf, tarragon, rosemary and thyme don't supply any vitamin K.What blocks vitamin K2 absorption? ›
Antibiotics -- Antibiotics, especially those known as cephalosporins, reduce the absorption of vitamin K in the body. Using them for more than 10 days may lower levels of vitamin K because these drugs kill not only harmful bacteria but also the bacteria that make vitamin K.What not to take with vitamin K2? ›
Vitamin K can have a serious and potentially dangerous interaction with anticoagulants such as warfarin (Coumadin®), as well as phenprocoumon, acenocoumarol, and tioclomarol, which are commonly used in some European countries [7,8].What supplements should not be taken with K2? ›
- mineral oil.
There is no evidence that vitamin K supplementation, in physiologic or even higher doses, causes serum enzyme elevations, liver injury or jaundice.Is K2 bad for kidneys? ›
Key Messages: CKD population are at risk of vitamin K deficiency. Supplementation of vitamin K2 is safe and improves the serum markers of its deficiency.Does vitamin K2 form blood clots? ›
Vitamin K likely plays an important role in blood clotting and promoting good heart and bone health. Some research suggests that K2 may be superior to K1 in some of these functions, but further research is needed to confirm this. For optimal health, focus on increasing food sources of both vitamin K1 and K2.Do probiotics have vitamin K2? ›
In addition to dietary sources, vitamin K2 is produced by gut bacteria. Recently it has been discovered that certain probiotic strains, that are already on the market, have the ability to produce vitamin K2 in vitro.Does kombucha have vitamin K2? ›
Sources of Vitamin K2
Natto, a fermented soy product, contains the greatest amount. Other plant-based sources include sauerkraut, tempeh, and kombucha, but their K2 content is inconsistent and will depend on the method of production.
The pickling or fermenting process that helps create pickles or slaws like kimchi and sauerkraut and makes them rich sources of probiotics also produces menaquinones, vitamin K2.Does kimchi contain vitamin K2? ›
Beyond the primarily plant-sourced K1 is under-appreciated K2 (also called menaquinone), found in animal foods and in fermented vegetables such as kimchi and sauerkraut.What plant foods have vitamin K2? ›
- raw sauerkraut.
- natto, a fermented soybean dish.
- unpasteurized kombucha.
- vegan kimchi.
- plant-based kefir.
Green Tea and COVID
And, if you're wondering where matcha green tea fits into the equation, it's known to contain natural levels of both K1 and K2, though not quite as high as those leafy greens above. However, by consuming the whole leaf powder, you're ingesting all present vitamins and minerals.
Food Sources of Vitamin K1 (mcg)
|Collards, frozen, boiled, ½ cup||530||662|
|Blueberries, raw, ½ cup||14||18|
|Iceberg lettuce, raw, 1 cup||14||18|
Data can now explain the process by which intrinsically insoluble, membrane-bound menaquinones can be shed into aqueous solutions, such as honey. The release of soluble forms of MK-7 from dead bacteria ultimately enriched honey in this nutritionally important vitamin K2 homologue.Does cucumber have K2? ›
Supports Strong Bones
With 22 percent of your daily vitamin K in every cup of cucumbers, eating more cukes is a good way to help maintain bone mineral density. Vitamin K (in the form of K2) is a fat-soluble vitamin that works with other essential nutrients like calcium and magnesium to preserve strong bones.
As mentioned earlier, ACV contains vitamin K2, which is helping in treating bronchial asthma.Do fermented chickpeas have vitamin K2? ›
That's why Together Health's Vitamin K2 is made with chickpeas, which are fermented with Bacillus subtilis nattō. Their Vitamin K2 brings you a highly biologically active form of vitamin K2 - one that's 10 times more efficiently absorbed than vitamin K1 from spinach.Does Greek yogurt have K2? ›
Popular fat-free greek yogurts have virtually zero Vitamin K2 while full fat greek yogurts have a fair amount of K2. But not all fatty foods are rich in K2.
Miso is a great natural source of vitamin K2, which helps calcium to be stored in our bones. Now, you may think you get plenty of vitamin K from green vegetables, but they contain vitamin K1, which is not thought to be as effective for this purpose – although it does have other important roles.