Vitamin K2 and Cardiovascular Health
Vitamin K is an essential compound that was first discovered in 1929 due to its rule in blood coagulation (i.e., blood clotting).
The origin of the letter ‘K’ stems from the initial nomenclature given by a German scientific journal, which called this compound as ‘Koagulationsvitamin’.
Since then, hundreds of clinical studies and research papers identified the potential role of vitamin K in the human body.
It promotes cardiovascular health, reduces the risk of fragile bones (i.e., osteoporosis), and prevents tooth decay.
Interestingly, most of these benefits are attributed to vitamin K2.
To break it down, there are two forms of vitamin K:
- Vitamin K1 (phylloquinone) – generally found in plant foods
- Vitamin K2 (menaquinone) – generally found in animal foods
In this article, we briefly discuss vitamin K2’s mechanism of action and how it affects cardiovascular health.
How does Vitamin K2 Work?
The primary role of vitamin K is to activate different proteins that interfere with blood clotting, cardiovascular health, and bone mineralization.
By regulating calcium metabolism and deposition, vitamin K2 improves the health of bones and prevents calcification of blood vessels and heart cavities, which could potentially predispose to atherosclerosis.
Despite the similarities between the two forms of vitamin K, many scientists believe that each compound serves different functions.
For instance, one animal study found that vitamin K2 reduces blood vessel calcification; when experimenting with vitamin K1, these findings were absent.
Additionally, studies conducted on humans showed that vitamin K2 supplementation improves bone and cardiovascular health, whereas vitamin K1 showed no such results.
In summary, vitamin K2 demonstrated more promising results when it comes to cardiovascular and bone health.
What is Cardiovascular Disease?
Cardiovascular disease (CVD) is responsible for over 17.9 million related deaths every year.
In the medical community, cardiovascular disease is an umbrella term that’s used to describe an array of pathologies.
These include coronary artery disease, peripheral artery disease, and stroke.
All of these ailments result from the irreversible clogging of a main artery, which deprives different tissues from oxygen and nutrients.
Depending on the affected organ, the patient could develop:
- Myocardial infarction (i.e., heart attack)
- Ischemic limb
The main culprit behind vascular obstruction is the oxidation of cholesterol that occurs in the lumen of those vessels.
What is Atherosclerosis?
Atherosclerosis is a term used in the medical literature to describe a complex mass that forms over decades.
This mass eventually leads to the partial or total obstruction of a blood vessel.
This plaque results from the accumulation of LDL (i.e., bad cholesterol) under the intima (innermost layer of the blood vessel).
When immune cells (e.g., macrophages) identify this plaque, they consider it as a foreign tissue, which precipitates a local immune and inflammatory reaction that results in dead macrophages and neutrophils, further adding to the size of the plaque.
The primary risk factors for atherosclerosis include:
- Dyslipidemia (e.g., high LDL, low HDL)
- Diabetes mellitus
- Chronic blood hypertension
- Oxidative stress (i.e., a high number of free radicals)
- Intravascular calcification (i.e., calcium build-up inside the arteries)
- Chronic inflammation
How does Vitamin K2 Help with Cardiovascular Health?
Calcium build-up inside blood vessels is an important risk factor for heart disease.
Consequently, foods and medications that can prevent the accumulation of calcium could potentially reduce the risk of cardiovascular disease.
As mentioned above, the primary way that vitamin K2 helps with this condition is by preventing the deposition of calcium inside the arteries.
In a 2004 study, researchers analyzed the effects of taking high amounts of vitamin K2 over the course of 7-10 years.
The results showed that individuals with the highest intake of vitamin K2 had a 52% reduction in the risk of intravascular calcification and a 57% risk reduction of dying from myocardial infarction.
In another study, 16,057 women had a lower risk of dying from cardiovascular disease after ramping up their vitamin K2 intake.
When comparing these findings to the effects of vitamin K1, researchers found a negligible impact of the latter.
With that being said, the two studies mentioned above are observational studies.
It means they could only be used to find a correlation between vitamin K2 intake and heart disease. And as you may know, correlation does not equal causation.
To simply this concept, here’s an analogy:
Drowning-related deaths are highest when people consume a lot of ice cream.
Obviously, ice cream consumption does not cause people to drown.
This is merely a correlation that occurs because both swimming and ice cream intake peak during the summer season.
The same thing applies to vitamin K2 intake and cardiovascular disease.
However, the example given in the analogy is on the extreme side of things since there is no mechanism that could potentially connect the two events.
On the other hand, vitamin K2 has a documented biological mechanism that explains its effectiveness in reducing the risk of cardiovascular disease.
Where to Get Vitamin K2?
Unfortunately, most foods labeled as ‘vitamin K-rich’ only contain vitamin K1.
While the body converts vitamin K1 to K2, the scale of this process is negligible, which means you may need to consume vitamin K2-rich foods or take dietary supplements.
Foods that contain large amounts of vitamin K2 include:
- Egg yolks
- Organ meats
If you are not getting sufficient amounts of vitamin K2 through your diet, supplements could largely compensate for any deficiency you have.
Interestingly, taking vitamin K2 with vitamin D showed synergetic effects, which means that dual supplementation leads to more positive effects.
This is more prominent with bone health since both vitamins promote mineralization and reduce the rate of bone resorption, which prevents osteoporosis.
Vitamin K2 offers several health benefits to the body.
Including, and not exclusive to, the promotion of cardiovascular health in susceptible and healthy individuals.
Hopefully, this article managed to convince you of the potential uses of vitamin K2 and why you should incorporate it into your diet.
- Newman, P. and Shearer, M. J. (1998) Vitamin K metabolism. In: Quinn, P. J. and Kagan, V. E. (eds) Fat-Soluble Vitamins. Subcellular Biochemistry, vol 30. Boston, MA: Springer.
- Schurgers, L. J., Teunissen, K. J. F., Hamulyák, K., Knapen, M. H. J., Vik, H. and Vermeer, C. (2007) Vitamin K-containing dietary supplements: Comparison of synthetic vitamin K1 and natto-derived menaquinone-7. Blood, vol.109(8) pp. 3279–3283.
- Vossen, L. M., Schurgers, L. J., van Varik, B. J., Kietselaer, B. L. J. H., Vermeer, C., Meeder, J. G., Rahel, B. M., van Cauteren, Y. J. M., Hoffland, G. A., Rennenberg, R. J. M. W., Reesink, K. D., de Leeuw, P. W. and Kroon, A. A. (2015) Menaquinone-7 supplementation to reduce vascular calcification in patients with coronary artery disease: Rationale and study protocol (VitaK-CAC Trial). Nutrients, vol.7(11) pp. 8905–8915.
- Spronk, H. M. H., Soute, B. A. M., Schurgers, L. J., Thijssen, H. H. W., De Mey, J. G. R. and Vermeer, C. (2003) Tissue-specific utilization of menaquinone-4 results in the prevention of arterial calcification in warfarin-treated rats. Journal of Vascular Research, vol.40(6) pp. 531–537.
- Schwalfenberg, G. K. (2017) Vitamins K1 and K2: The emerging group of vitamins required for human health. Journal of Nutrition and Metabolism, vol.2017 Article 6254836.
- World Health Organisation (2021). https://www.who.int/health-topics/cardiovascular-diseases
- Lusis, A. J. (2010) Atherosclerosis. Nature, vol.407(6801) pp. 233–241.
- Kramer, C. K., Zinman, B., Gross, J. L., Canani, L. H., Rodrigues, T. C., Azevedo, M. J. and Retnakaran, R. (2013) Coronary artery calcium score prediction of all cause mortality and cardiovascular events in people with type 2 diabetes: systematic review and meta-analysis. The BMJ, vol.2013 Article 346.
- Geleijnse, J. M., Vermeer, C., Grobbee, D. E., Schurgers, L. J., Knapen, M. H., van der Meer, I. M., Hofman, A. and Witteman, J. C. M. (2004) Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: The Rotterdam Study. Journal of Nutrition, vol.134(11) pp. 3100–3105.
- Gast, G. C. M., de Roos, N. M., Sluijs, I., Bots, M. L., Beulens, J. W. J., Geleijnse, J. M., Witteman, J. C., Grobbee, D. E., Peeters, P. H. M. and van der Schouw, Y. T. (2009) A high menaquinone intake reduces the incidence of coronary heart disease. Nutrition, Metabolism & Cardiovascular Disease, vol.19(7) pp. 504–510.
- Kidd, P. M. (2010) Vitamins D and K as pleiotropic nutrients: Clinical importance to the skeletal and cardiovascular systems and preliminary evidence for synergy. Alternative Medicine Review, vol.15(3) pp. 199–222.