The Role of Vitamin K2 in Heart and Bone Health Vitamin K2 is a fat-soluble vitamin with distinct roles in calcium regulation that affect both cardiovascular and skeletal systems. Unlike vitamin K1, which primarily supports blood clotting, vitamin K2 helps direct calcium to bones and teeth while limiting its accumulation in soft tissues such as arterial walls. Understanding these mechanisms clarifies why K2 is important for maintaining bone density and reducing arterial calcification. Biology and subtypes Vitamin K2 exists in several menaquinone forms, notably MK-4 and MK-7, which differ in chain length, tissue distribution, and half-life. MK-4 is found in some animal foods and tissues, while MK-7, commonly derived from fermented foods, tends to have a longer circulating half-life and may support steady activation of vitamin K–dependent proteins. Two key vitamin K–dependent proteins relevant to heart and bone health are osteocalcin, which binds calcium in bone, and matrix Gla protein (MGP), which inhibits vascular calcification. Evidence for cardiovascular benefits Observational studies and some randomized trials indicate an association between higher dietary intake or circulating status of vitamin K2 and lower markers of arterial calcification and cardiovascular events. Vitamin K2 activates MGP; without adequate activation, calcium can deposit in arterial walls, reducing elasticity and increasing cardiovascular risk. While evidence is promising, many studies are observational; larger randomized controlled trials are needed to confirm causality and optimal dosing strategies. Role in bone health Vitamin K2 contributes to bone quality by activating osteocalcin, enabling efficient incorporation of calcium into the bone matrix. Clinical studies have reported improvements in bone mineral density and reductions in fracture risk with vitamin K2 supplementation, particularly in older adults. The effect is most consistent when vitamin K2 is combined with adequate calcium and vitamin D, reflecting their complementary roles: calcium provides substrate, vitamin D supports absorption, and vitamin K2 directs deposition into bone. Sources and deficiency signals Natural sources of vitamin K2 include fermented foods such as natto, certain cheeses, and animal products like egg yolk and liver. Dietary intake varies by region and dietary habits; some populations may have limited K2 consumption. Signs that may suggest suboptimal vitamin K2 status include easy bruising, bleeding tendencies, lower bone density, and clinical indicators of arterial stiffness. Laboratory assessment of vitamin K status can be complex; healthcare professionals may evaluate risk and consider targeted testing in specific situations. Practical considerations When assessing strategies to support bone and cardiovascular health, consider the balance of evidence, individual dietary intake, and interactions with medications (for example, vitamin K can interfere with some anticoagulants). For further reading on complementary nutrient strategies and supplement formats, see the iron supplement guide and an overview of liposomal capsules. General information about product availability is available at Topvitamine. The Topvitamine resource on vitamin K2 provides a concise summary of its physiological roles and implications: [The Role of Vitamin K2 in Heart and Bone Health](https://www.topvitamine.com/blogs/news/the-role-of-vitamin-k2-in-heart-and-bone-health-topvitamine). Conclusion Vitamin K2 supports calcium handling in the body, contributing to bone mineralization and helping to limit vascular calcification. Current evidence supports its biological relevance for heart and bone health, though clinical recommendations should be individualized and consider overall diet, vitamin D and calcium status, and medication use.