Your cardiovascular system needs nutritional support to keep running in excellent condition that includes efficiently responding to the challenges that may impact the health of blood vessels, such as inflammation, calcium deposition and hardening of arteries.
Research in the last decade has revealed the important role of vitamin D in heart health. And while people are getting increasingly aware of this, few, however, realize that there is another nutrient which is nearly as important in delivering heart benefits as the sunshine vitamin. Yes, we are talking about vitamin K2. In fact, vitamin D3 and vitamin K2 work in tandem to keep both our bones and heart in good shape. How?
Let’s find out, but not before taking a short detour and talking about the ‘good and bad’ of calcium.
We have known for a long time how calcium works in the body. It is an all too important mineral for making your bones strong and healthy. But it is also required for other important functions; for example, cellular signalling, blood clotting, transmission of nerve impulses, muscle contraction (that includes your heart muscle), regulation of hormones and so much more. So, calcium is important and supplementation may be necessary if you are not getting enough from your food.
However, the problem is that calcium needs to be properly regulated in the bloodstream and tissues, failing which can lead to the mineral settling in the most unwanted places and resulting in serious health issues, especially impacting the bones, arteries and heart. Calcium build-up in the arteries contributes to plaque formation, making arteries stiff and inflexible and increasing the risk of high blood pressure, blood clots, heart attacks and strokes.
Interestingly, your body has robust, effective mechanisms in place to cope with the calcification issues in the arteries; and that’s where vitamin K2 enters the picture. While vitamin D helps your body absorb calcium from the food you eat or from the supplements you take, it is vitamin K2 that hand-holds and guides this calcium towards where it needs to be.
Vitamin D3 in heart health
We know vitamin D for its classical role in proper bone formation and growth. It helps the body to absorb calcium while preventing osteoporosis and reducing the risk of fractures. But vitamin D may be doing more than just building strong bones. Research shows that it plays a key role in your overall health and, in particular, cardiovascular health.
Heart muscle cells and the cells in the endothelium need vitamin D to work. We know this as these cells have vitamin D receptors. Studies show that vitamin D3 deficiency contributes to high blood pressure, inflammation, calcium deposits and plaque build-up in the arteries, and vascular stiffness. Insufficient levels of the sunshine vitamin also cause metabolic syndrome and impaired insulin sensitivity.   All these are underlying risk factors for cardiovascular disease such as heart attack, stroke, heart failure and peripheral artery disease. Vitamin D lowers these risks and significantly brings down inflammatory markers such as C-reactive protein.
But, it seems the picture is not yet complete for when it comes to heart health, vitamin K2 seems to be every bit as crucial as vitamin D.
Vitamin K2: A little known nutrient we need for a healthy heart (and bones)
Vitamin K2 performs many other important functions but let us, for now at least, focus on its role in cardiovascular health.
Vitamin K2 is an integral part of the mechanism your body uses to protect the arteries from calcium build-up. What vitamin K2 does is that it activates two enzymes; Matrix Gla-protein (MGP) and Osteocalcin.
MGP, produced by smooth muscle cells of the blood vessels, is possibly the most important inhibitor of calcification in the arteries.  MGP binds to calcium in the blood vessels and removes it from there. But guess what, it’s activation is dependent on vitamin K2.
In addition, vitamin K2 also activates osteocalcin. It is a protein secreted by osteoblasts, cells responsible for building up the skeleton (versus osteoclasts that break the bones during bone remodelling and repair). Now, osteocalcin binds to the calcium floating in the bloodstream and nudges it towards the bone matrix where it is integrated and contributes to a stronger skeletal structure.
Vitamin D allows the calcium to be available to the body but without vitamin K2, this calcium wouldn’t know which direction to move in. In a nutshell, Vitamin K2 makes sure the calcium ends up where it should be, and steers it clear from places where it doesn’t belong, for example, deposited in the blood vessels and arteries.
Studies show that vitamin K2 deficiency puts you at an increased risk of coronary heart disease. Many studies, including the famous Rotterdam study, have revealed that people with sufficient levels of vitamin K2 have a lower risk of arterial calcification and death from coronary heart disease.  
Conclusion: Taking calcium and vitamin D3? Add vitamin K2.
Most people don’t realize that by taking calcium supplements alone, they are putting their heart health in jeopardy. Even if you are taking vitamin D3 but lacking in Vitamin K2, it would result in excess calcification causing clogged arteries and other health issues.
If you are taking calcium and vitamin D3 supplements, it is now time to make vitamin K2 supplementation a part of your heart-healthy regimen, especially if you are on statin drugs as these cholesterol-lowering drugs deplete K2 levels in the body. Your heart will thank you for it!
- V. Kunadian, G. A. Ford, B. Bawamia, W. Qiu, and J. E. Manson. Vitamin D deficiency and coronary artery disease: A review of the evidence. American Heart Journal, vol. 167, no. 3, pp. 283–291, 2014.
- Ioana Mozos, Otilia Marginean. Links between Vitamin D Deficiency and Cardiovascular Diseases. BioMed Research International. 2015
- E. Theuwissen, E. Smit and C. Vermeer, 'The Role of Vitamin K in Soft-Tissue Calcification,' Adv. Nutr. 3(2), 166–173 (2012).
- Johanna M. Geleijnse et al. Dietary Intake of Menaquinone Is Associated with a Reduced Risk of Coronary Heart Disease: The Rotterdam Study. The Journal of Nutrition. 2004.
- G.C. Gast et al. A High Menaquinone Intake Reduces the Incidence of Coronary Heart Disease. Nutr. Metab. Cardiovasc. Dis. 2009.