The benefits of vitamin K on heart health
Vitamin K is important for optimal health, and the benefits of vitamin K are wide ranging. For example, vitamin K has many positive benefits on the skeletal system (HERE). In addition to aiding bone health, vitamin K is also suspected of assisting cardiovascular (heart and surrounding vessel) health. More specifically, vitamin K may help delay or prevent cardiovascular disease (CVD), and CVD related disorders, such as coronary heart disease.
There has been a focus on the role of arterial stiffness in the development of cardiovascular disease in recent years. Arterial stiffness is a term given to the elasticity of the arteries. Generally speaking, hardening or stiffening of the arteries is unfavourable, and is more conducive to CVD. Arterial stiffness is referred to as arteriosclerosis. Simply put, the harder or stiffer the arteries, the greater the pressure of blood against the walls of the arteries. On the other hand, a more elastic artery will cope much better with the pressure exerted upon by the blood. Of particular importance is the carotid artery, as this handles a large volume of blood each beat, plus it tends to be the site at which arterial stiffness, and calcification, can be most destructive.
Arterial stiffness typically accompanies age, along with other cardiovascular risk factors, and is caused by various phenomena including: breaks in fibre, accumulation of collagen, fibrosis, medial smooth muscle necrosis…inflammation and calcification. The role that vitamin plays, specifically in regard to the last two phenomena, will be described below.
Here’s the interesting part: a lower prevalence of calcification and coronary heart disease mortality is found in people with the highest intake of vitamin K, and in particular vitamin K2. Vitamin K2 therefore appears, at least on the surface, beneficial to cardiovascular health. Most studies thus far have been observational, however. This means that where there ‘tends’ to be a high intake of vitamin K2, the incidence of coronary heart disease appears to be low. But, we don’t know if the vitamin K2 is actually causing the lower heart disease incidence, as it could be down to many other factors (e.g. vegetable intake, sunlight, stress management, exercise etc.).
Multiple benefits of vitamin K
That being said, there does appear to be physiological mechanisms by which vitamin K may directly aid cardiovascular health. For example, vitamin K may help to slow or prevent the progression of calcification in arteries, most notably the carotid artery. [Remember above, arterial calcification is part of the stiffening or hardening process – not a good thing]. More specifically, vitamin K2 supplementation enhances something known as MGP carboxylation – decreased MGP carboxylation decreases the ability of MGP to inhibit arterial calcification.
[MGP is a potent inhibitor of arterial calcification (Schurgers et al. 2008)]
Thus, with a lower intake of vitamin K comes a decline in MGP, which would otherwise serve to prevent the calcification of arteries.
In addition, vitamin K may help to attenuate or slow the rise in inflammatory markers, and again delay the onset of arterial stiffening. For instance, observational data has shown an inverse association between vitamin K and IL-6 and CRP (two inflammatory markers), whilst intervention studies showed a decline in inflammation with high dose vitamin K2 supplementation in people with arthritis.
Benefits of vitamin K – summary
Coronary artery calcification has recently emerged as an important predictor of cardiovascular disorder. Recent scientific literature highlights the role that vitamin K plays in halting the increases in arterial calcification. By maintaining levels of MGP, and perhaps by reducing inflammation also, vitamin K helps to safeguard vascular health. In turn, it likely prevents, or at least delays, coronary artery calcification, and thus reduces ones risk for CVD.