Group items tagged

Regression of warfarin-induced medial elastocalcinosis by high intake of vitamin K in rats. Schurgers LJ, Spronk HM, Soute BA, Schiffers PM, DeMey JG, Vermeer C. Blood. 2007 Apr 1;109(7):2823-31. PMID: 17138823 DOI 10.1182/blood-2006-07-035345. This is the first study in rats demonstrating that AC and the resulting decreased arterial distensibility are reversible by high-VK intake

Deficiency of K2 in both mice and humans is associated with coronary calcification; low vitamin K2 levels are associated with increased activity of Gla matrix protein, an enzyme that causes calcium deposition in artery walls. People who take warfarin (Coumadin®), a potent blocker of vitamin K2, experience more arterial and heart valve calcification. The 2004 Rotterdam Heart Study was the experience that really brought this concept closer to our interests. This well-conducted study of 4800 Dutch demonstrated an association of vitamin K2 intake with 57% reduction in cardiovascular events and lesser degrees of aortic calcification (another surrogate for atherosclerosis). Benefit appeared to be associated with a daily K2 intake of 32.7 micrograms per day (Geleijnse JM et al 2004). An important corollary of this study is that it suggests that a vitamin K2-mediated reduction in coronary calcification is accompanied by reduced likelihood of heart attack and other events.

"[Vitamin K and Bone Update. The biological effects of vitamin K(2) on bone quality.] Amizuka N, Li M, Guo Y, Liu Z, Suzuki R, Yamamoto T. Clin Calcium. 2009 Dec;19(12):1788-96. Japanese. PMID: 19949270 Post-transcriptional maturation with the presence of vitamin K(2) promotesgamma-carboxylation of osteocalcin, enabling further binding to hydroxyapatite, from which one could infer that vitamin K(2) increased the quality of bone matrix. For instance, vitamin K(2) rescued the impaired collagen mineralization caused by Mg insufficiency, by promoting a re-association of the process of collagen mineralization with mineralized nodules. Sodium warfarin, which antagonizes the function of vitamin K(2), reduced the binding of osteocalcin to bone matrices, and consequently resulted in crystalline particles being dispersed throughout the osteoid without forming mineralized nodules. Therefore,gamma-carboxylated Gla proteins mediated by vitamin K(2) appear to play a pivotal role in normal mineralization in bone."