When people think about vitamin K, they usually think about its key role in blood clotting. You probably don’t know the other health benefits of Vitamin K2. Even though it does play an important role in the cardiovascular system, its benefits go far beyond the health of your blood. It is important to learn the differences between the different types of vitamin K and what they do. How can you get more vitamin K in your diet? 

What Is Vitamin K2 versus K1?

First, there are different types of vitamin K, with the most common examples being vitamin K2 and vitamin K1. Vitamin K was discovered in the early 1900s after an experiment went wrong. A group of research animals bled to death following a restrictive diet that removed cholesterol and unknowingly, also vitamin K. Without vitamin K, their blood could not clot.

Danish researcher Henrik Dam published his findings in a German research journal where the chemical was translated as Koagulationsvitamin and then became known as “Vitamin K”.

Scientist Edward Doisy did follow-up research to determine the structure of Vitamin K and in 1943, Dam and Doisy shared the Nobel Prize for their efforts.

This led to more research on vitamin K that uncovered multiple types. The first is called vitamin K1. This is also called phylloquinone, and it is frequently found in leafy green vegetables. This form of vitamin K is responsible for the vast majority of vitamin K people consume in their diets. 

The other type of vitamin K is called vitamin K2. It is frequently found in fermented foods, and animal products, and is even produced by bacteria that live in your gut. There are several subcategories of vitamin K2. These are usually called MKs and range from MK4 to MK7 and even MK13. Overall, vitamin K1 and vitamin K2 make up the vast majority of vitamin K that people consume. 

What Are the Health Benefits of Vitamin K2?

Even though most of the vitamin K that people consume comes from vitamin K1, there are numerous health benefits to consuming vitamin K2 as well. A few examples of the major health benefits of vitamin K2 include: 

The Role of Vitamin K2 in Blood Clotting

One of the most important roles of vitamin K in the human body is blood clotting. This role includes vitamin K2. It is true that excessive blood clotting can be a bad thing; however, it is important to strike a healthy balance. If the blood does not clot when it is supposed to, it is possible for people to bleed to death. Without enough vitamin K, even a paper cut can lead to significant medical complications.

For example, there are a lot of people who take a medication called warfarin to prevent the blood from clotting too quickly. If you are taking blood thinners, talk to your doctor before starting to increase your vitamin K2 thru diet or a supplement since there may be an impact on the effectiveness of your blood thinner.

Vitamin K2 plays a significant role in blood clotting. Furthermore, medical studies have shown that the impact of vitamin K2 on blood clotting is significantly more powerful than the impact of vitamin K1. As a result, it is important for people to monitor their food intake to make sure they are getting enough vitamin K, including vitamin K2. This is particularly important for people who take blood-thinning medications, such as warfarin. People need to meet with their doctors regularly to make sure they are getting enough vitamin K and that their blood is behaving as it should. 

Vitamin K2 Can Prevent Bone Fractures

In addition, medical researchers believe that vitamin K2 plays a significant role in the prevention of bone fractures. There are a number of vitamins and minerals that are responsible for bone health. Most people think about calcium and vitamin D when it comes to the health of their bones. At the same time, Vitamin K is also important.

For example, Vitamin K is responsible for activating numerous proteins that are required for the growth and development of new bone tissue. Furthermore, multiple studies have been produced showing that low levels of vitamin K1 and vitamin K2 can increase the risk of bone fractures.

On the other hand, when the study breaks up vitamin K1 and vitamin K2, research has shown that vitamin K2 is significantly more important. For example, the MK4 subtype of vitamin K2 appears to be particularly important in protecting the health of the bones. Ultimately, Vitamin K is critical for the overall health of the bone structure. It is important for everyone to make sure they consume enough vitamin K2 and their diets to make sure their bones are healthy. This is particularly important as they get older, as the density of bone tissue can decline with age, making people more susceptible to bone fractures. 

Vitamin K2 Is Important for Cardiovascular Health

Finally, vitamin K2 also appears to play a critical role in the overall health of your heart. Vitamin K is responsible for activating a specific protein that prevents calcium from depositing in the arteries. If calcium is allowed to deposit in the arteries, it can lead to blood clots, restricting blood flow to important parts of the body. 

Numerous medical studies have been produced showing that vitamin K2 is better at reducing calcium deposits in the cardiovascular system than vitamin K1. Therefore, it is important for people to pay close attention to how much vitamin K they are consuming. Specifically, studies have shown that MK7 form of vitamin K2 appears to be particularly beneficial in protecting the health of the heart. Some people have even taken supplements to help them protect their cardiovascular systems.

Many of these benefits are relatively new, so there are still a lot of ongoing studies. Even though it is important for people to ensure they consume enough vitamin K2 to protect their hearts, it is just as important for people to make sure they exercise regularly to prevent the development of chronic medical complications. It will be interesting to see what further research reveals. 

These are just a few of the many benefits of consuming vitamin K2 regularly. It is critical for people to watch their diets closely to make sure they get enough vitamin K2. 

How does Vitamin K2 reduce the calcification of arteries? (introducing MGP)

Vitamin K2 plays a vital role in reducing arterial calcification by activating a protein called matrix Gla protein (MGP). MGP is a potent inhibitor of vascular calcification, which means it helps prevent calcium from being deposited in the arterial walls. Let me explain the mechanism in more detail.

Calcification of the arteries, specifically in the tunica media (middle layer) of the arterial wall, contributes to the development of atherosclerosis and arterial stiffness, both of which are risk factors for cardiovascular disease. MGP is synthesized by vascular smooth muscle cells and is secreted into the extracellular matrix of the arterial wall.

MGP requires activation through a process called carboxylation, which adds carboxyl groups to specific glutamic acid residues in the protein. This carboxylation process is dependent on vitamin K, specifically vitamin K2 (menaquinone), as a cofactor. When MGP is carboxylated, it becomes biologically active and can bind to calcium ions and hydroxyapatite crystals, inhibiting their deposition in the arterial wall and thereby preventing calcification.

However, if there’s a deficiency of vitamin K2 or if the body’s demand for vitamin K2 is higher than the supply, MGP may remain undercarboxylated, which means it’s inactive and cannot perform its function of inhibiting calcification. This can lead to increased arterial calcification and associated cardiovascular risks.

In summary, vitamin K2 is crucial for the activation of MGP, which helps prevent arterial calcification and promotes heart health. Ensuring an adequate intake of vitamin K2 through diet or supplementation may contribute to reducing the risk of cardiovascular disease by maintaining the proper functioning of MGP.

Is There Good Medical Research on Vitamin K2?

A lot of the research surrounding vitamin K2 is still relatively new. Therefore, a lot of medical professionals are still producing research studies on vitamin K2. At the same time, there is already a lot of research data showing just how beneficial it is for people to consume vitamin K2 on a regular basis. For example, a few important studies people may want to look at include:

• A medical study was produced showing that people who take vitamin K2 supplements, specifically MK7, might be able to reduce their risk of developing cardiovascular complications.
• Some observational studies have been produced showing that vitamin K2 is better than vitamin K1 at helping people protect their blood vessels from calcium deposition. 
• Medical studies have also been produced to showing that lower levels of vitamin K1 and vitamin K2 could increase someone’s risk of developing a serious bone fracture. 
• Medical studies have also shown that eating a single serving of natto that contains a lot of vitamin K2 could significantly change the way someone’s blood clots for up to four days.

These are just a few of the many medical studies that have been published so far taking a look at the impact of vitamin K2 on different parts of the body. It will be interesting to see what future medical studies show. 

The Rotterdam Study and Vitamin K2

Now, let’s discuss some research that supports the use of vitamin K2 in the prevention of heart disease in humans. Here are a few notable studies:

1. Geleijnse, J. M., Vermeer, C., Grobbee, D. E., Schurgers, L. J., Knapen, M. H., van der Meer, I. M., … & Witteman, J. C. (2004). Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. The Journal of Nutrition, 134(11), 3100-3105.

The Rotterdam study observed that a higher dietary intake of vitamin K2 was associated with a reduced risk of coronary heart disease, while no such association was found with vitamin K1.

It was a prospective cohort study conducted on 4,807 participants aged 55 years and older, living in Rotterdam, the Netherlands. The study aimed to investigate the association between dietary intake of vitamin K2 (menaquinone) and the incidence of coronary heart disease (CHD).

Foods highest in vitamin K2 in the study were primarily of animal origin and fermented foods, such as:

1. Dairy products, particularly hard and semi-hard cheeses
2. Fermented foods, like natto (a traditional Japanese food made from fermented soybeans)
3. Egg yolks
4. Chicken, especially the liver
5. Meat, such as beef and pork

As for the limitations of the Rotterdam study, there are a few to consider:

1. The study relied on self-reported dietary habits from a food frequency questionnaire, which can be subject to recall bias and measurement errors.
2. The study population was primarily Caucasian and living in a specific geographic region (Rotterdam, the Netherlands), which may limit the generalizability of the findings to other populations or ethnicities.
3. As with any observational study, it is not possible to establish a causal relationship between vitamin K2 intake and reduced risk of CHD. The study only found an association between the two, and there could be other factors or confounders that were not accounted for.

Despite these limitations, the study provided valuable insights into the potential benefits of vitamin K2 in relation to heart health. It’s important to remember that additional research, including randomized controlled trials, would be necessary to establish causality and confirm the findings from this observational study.

Other Studies on the Role of Vitamin K2 and its role in reducing coronary calcifications

The Rotterdam Study followed participants for a median duration of 7.2 years. During this period, the researchers assessed the incidence of coronary heart disease, as well as all-cause mortality and aortic calcification, in relation to the participants’ dietary intake of vitamin K1 (phylloquinone) and vitamin K2 (menaquinone).

As for other studies that confirm the results of the Rotterdam Study, there isn’t a direct comparison with the Framingham Study, as the latter primarily investigated risk factors for cardiovascular disease, rather than focusing on the role of specific nutrients like vitamin K2. However, there are other studies that have further examined the potential benefits of vitamin K2 for heart health:

• Gast, G.C., de Roos, N.M., Sluijs, I., Bots, M.L., Beulens, J.W., Geleijnse, J.M., Witteman, J.C., Grobbee, D.E., Peeters, P.H., van der Schouw, Y.T. (2009). A high menaquinone intake reduces the incidence of coronary heart disease. Nutrition, Metabolism and Cardiovascular Diseases, 19(7), 504-510.

The Gast study, conducted on a Dutch population, found that a high intake of menaquinone (vitamin K2) was associated with a reduced risk of coronary heart disease.

This study was a prospective cohort study, which included 16,057 women aged 49-70 years from the Prospect-EPIC cohort. The participants were free of cardiovascular disease at baseline, and they were followed for an average of 8.1 years. Dietary intake data were collected using a food frequency questionnaire, and the researchers calculated the intake of both phylloquinone (vitamin K1) and menaquinone (vitamin K2) for each participant.

During the follow-up period, 480 incident cases of CHD were documented. The study found that a high intake of menaquinone (vitamin K2) was associated with a reduced risk of CHD. Specifically, women in the highest quartile of vitamin K2 intake had a 20% lower risk of CHD compared to those in the lowest quartile. Notably, this association was more pronounced in participants with hypertension and a higher body mass index (BMI).

On the other hand, the study did not find a significant association between phylloquinone (vitamin K1) intake and CHD risk. This suggests that the potential cardiovascular benefits might be specific to vitamin K2 and not to vitamin K1.

It’s important to note that, like other observational studies, the Gast study cannot establish a causal relationship between vitamin K2 intake and reduced CHD risk. However, the study does provide additional support for the potential role of vitamin K2 in heart health and corroborates the findings of the earlier Rotterdam Study. Further research, including randomized controlled trials, would be needed to confirm these associations and establish causality.

• Zwakenberg, S.R., den Braver, N.R., Engelen, A.I., Feskens, E.J., Vermeer, C., Boer, J.M., Verschuren, W.M., van der Schouw, Y.T., Beulens, J.W. (2017). Vitamin K intake and all-cause and cause-specific mortality. Clinical Nutrition, 36(5), 1294-1300.

The Zwackenberg study, part of the EPIC-NL cohort, investigated the association between dietary vitamin K intake and all-cause and cause-specific mortality. It observed that higher intakes of vitamin K2, but not vitamin K1, were associated with a reduced risk of all-cause mortality, and specifically cancer and cardiovascular mortality.

While these studies support the findings of the Rotterdam Study, it’s essential to note that they are also observational in nature. Additional research, including randomized controlled trials, is necessary to establish causality and further confirm the potential heart health benefits of vitamin K2.

• .Beulens, J. W., Bots, M. L., Atsma, F., Bartelink, M. L., Prokop, M., Geleijnse, J. M., … & van der Schouw, Y. T. (2009). High dietary menaquinone intake is associated with reduced coronary calcification. Atherosclerosis, 203(2), 489-493.

This study found that a high dietary intake of vitamin K2 was associated with reduced coronary artery calcification, which is a significant factor in the development of heart disease.

How much Vitamin K2 do you need?

Unfortunately, the Gast 2009 study did not report the exact daily intakes of Vitamin K2 in the different quartiles. However, the study did report the range of Vitamin K2 intake for each quartile. The range of daily Vitamin K2 intake for the lowest quartile was <20.3 micrograms/day, for the second quartile it was 20.3-32.7 micrograms/day, for the third quartile it was 32.7-50.6 micrograms/day, and for the highest quartile it was >50.6 micrograms/day.

Note: CHD = coronary heart disease; RR = relative risk; CI = confidence interval. The reference group is the lowest quartile of vitamin intake.

Although the primary focus of the study was on mortality outcomes, it did report the average daily intake of vitamin K1 (phylloquinone) and vitamin K2 (menaquinone) for the participants.

According to the Zwakenberg study, the mean daily intake of vitamin K2 (menaquinone) in the cohort was 31.6 µg/day. The study also reported that the main sources of vitamin K2 in the participants’ diets were cheese (54%), milk and milk products (22%), and meat (15%).

It’s important to note that the recommended daily intake of vitamin K can vary depending on age, sex, and life stage. The adequate intake (AI) of vitamin K for adult men is 120 µg/day, while for adult women, it’s 90 µg/day. However, these recommendations are mainly based on vitamin K1 intake, as data on the optimal intake of vitamin K2 are limited.

As with any dietary assessment, it’s essential to consider that the average intake in a specific population may not be directly applicable to individuals with different dietary habits or cultural backgrounds. It’s always a good idea to consult with a healthcare professional to determine the appropriate vitamin K intake based on individual needs and circumstances.

How To Get More Vitamin K2 in Your Diet

Clearly, there are a lot of potential benefits that come with consuming vitamin K2. At the same time, foods that contain lots of vitamin K1 do not necessarily contain lots of vitamin K2. Therefore, it is important to take a closer look at how someone might be able to get more vitamin K2 in their diet. 

Those who are looking for greater levels of vitamin K2 MK4 should try to stick with animals and dairy products. For example, lots of organ meats, including kidneys and liver, contain lots of vitamin K2 MK4. This subtype can also be found in relatively high levels in cheese, eggs, butter, and chicken. Read our full article about foods high in vitamin K2 here.

Anyone who is looking for greater levels of vitamin K2 MK7 should try to target fermented foods. For example, kimchi, which is a Korean dish that is made from fermented cabbage, contains very high levels of vitamin K2 MK7. Natto, which is a Japanese dish made from fermented soybeans, also contains very high levels of vitamin K2 MK7.

It is also possible that the body may convert some types of vitamin K into other types when they are required.