Emerging evidence suggests that calcium from bone is deposited in the arteries. This leads to calcification in valves and vessels, which is associated with a 3 to 4-fold higher risk of coronary heart disease. There is currently no effective treatment available for vascular calcification and treatment is targeted to relieve symptoms. Therefore, due to the increased cardiovascular risk it is essential to attempt to lower the burden of vascular calcification and associated health care costs. A better understanding of the mechanisms underlying soft tissue calcification that occurs in aging and high risk populations is needed to discover new treatment options.
Calcium and vitamin D supplementation is frequently advised in older adults for the prevention of osteoporosis and to reduce the risk of fractures and falls. However, recent randomized trials showed that individuals taking calcium and vitamin D were at higher risk of cardiovascular disease. The widespread use of vitamin D and calcium supplements, and the fortification of vitamin D in food products, underscores the need for further investigation.
Vitamin D and vitamin K are fat-soluble vitamins. Vitamin D plays an important role in calcium homeostasis, and an optimal vitamin D status is related to improved cardiovascular health. Vitamin K is mostly known for its beneficial effects on blood coagulation, however, recent studies suggest a role in bone health and in reducing vascular calcification and cardiovascular disease. Vitamin K occurs in our diet in two forms: vitamin K1 mostly found in green leafy vegetables and vitamin K2 mainly found in animal foods, fermented dairy such as cheese, and natto (fermented soy beans). Vitamin K2 includes a range of vitamin K forms and differs from vitamin K1 in its side-chain length and degree of saturation. Vitamin K2 is the most biologically active form and has a longer half-life than (days vs. hours) vitamin K1.
Vitamin K is required for the maturation of several proteins through its role as a cofactor for the enzyme γ-glutamyl carboxylase. It plays an important role in the synthesis of numerous blood clotting factors, and calcium and bone metabolism. These vitamin K-dependent proteins are also known as Gla proteins and have a specific affinity for calcium. Vitamin K deficiency results in the synthesis of under-carboxylated, biologically inactive Gla-proteins– a risk factor for calcification.
Recent studies show that vitamin K reduces coronary calcification and cardiovascular disease. New evidence suggests that vitamin K combined with vitamin D can lower vascular calcification more than the effect of either alone. This presentation will give a brief overview of the current body of evidence of joint associations between vitamin D and vitamin K with both bone and cardiovascular health. Some new data about the use of vitamin D supplement use combined with a low vitamin K status on survival and cardiovascular disease risk will be presented as well.
These promising results of the joint associations of vitamin D and vitamin K in relation to cardiovascular health stimulate further follow-up studies to better understand the clinical implications of this relationship to promote cardiovascular health.