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The vitamin K dependant protein osteocalcin may have a positive effect on reducing obesity and diabetes, suggests a new study with mice.\nResearchers writing in the journal Cells studied the effect bone cells have in energy regulation, and found that osteocalcin plays a key role in regulating insulin activity.

"[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."

Vitamin K has been known as the coagulation vitamin, because of its role in the blood-clotting process. However, research over the last few decades has shown that the role of K Vitamins - and natural Vitamin K2, the menaquinones, in particular - has been greatly expanded. Of note, K Vitamins activity outside the liver is required for calcium utilization, the key factor in maintaining both bone and cardiovascular health.\n\nVitamin K2 helps to activate vitamin K-dependent proteins responsible for healthy tissues. In bone, it activates osteocalcin, a protein required to bind calcium to the mineral matrix, thus strengthening the skeleton. In circulation, Vitamin K2 participates in carboxylation of Matrix Gla Protein (MGP), the most potent inhibitor of arterial calcification known, lowering the risk of vascular damage.

Effect of low dose vitamin K2 (MK-4) supplementation on bio-indices in postmenopausal Japanese women. Koitaya N, Ezaki J, Nishimuta M, Yamauchi J, Hashizume E, Morishita K, Miyachi M, Sasaki S, Ishimi Y. J Nutr Sci Vitaminol (Tokyo). 2009 Feb;55(1):15-21. PMID: 19352059 It has been reported that treatment with a pharmacological dose (45 mg/d) of menaquinone-4 (MK-4) prevents bone loss in postmenopausal women. However, it is not known whether supplementation with low dose MK-4 has beneficial effects on bone metabolism in healthy women. The aim of this study is to examine the effects of the supplementation of 1.5 mg/d MK-4 for 4 wk on bone and lipid metabolism in healthy postmenopausal Japanese women. The study was performed as a randomized double blind placebo-controlled trial. The participants aged 53-65 y were randomly assigned to 2 groups and supplemented with 1.5 mg/d of MK-4 or a placebo for 4 wk (n=20 for each group). The most marked effects of MK-4 intake were observed on serum osteocalcin (OC) concentrations. Serum undercarboxylated OC (ucOC) concentration decreased, and the gamma-carboxylated OC (GlaOC) and GlaOC/GlaOC+ucOC ratio that indicates the degree of OC gamma-carboxylation increased significantly at 2 and 4 wk compared with that at baseline in the MK-4 group. The serum ucOC and GlaOC concentrations in the MK-4 group were significantly different from those in the placebo group at 2 wk. These results suggest that supplementation with 1.5 mg/d MK-4 accelerated the degree of OC gamma-carboxylation. The concentrations of serum lipids and other indices were not different between the groups at either intervention period. Thus, the additional intake of MK-4 might be beneficial in the maintenance of bone health in postmenopausal Japanese women.

Stress fractures in the Israeli defense forces from 1995 to 1996. Givon U, Friedman E, Reiner A, Vered I, Finestone A, Shemer J. Clin Orthop Relat Res. 2000 Apr;(373):227-32. PMID: 10810481 Serum levels of bone specific alkaline phosphatase and osteocalcin were elevated in patients with high grade stress fractures compared with control subjects with no symptoms: 37.6 versus 26.2 units/L, and 10.8 versus 8.8 ng/mL, respectively. Levels of 25-hydroxy vitamin D were lower in patients with high grade stress fractures (25.3 ng/mL) than in control subjects (29.8 ng/mL). This study revealed that several parameters can distinguish soldiers with high grade stress fractures, but their predictive value and precise pathogenetic role remain unclear.

Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7.\nSchurgers LJ, Teunissen KJ, Hamulyák K, Knapen MH, Vik H, Vermeer C.\nBlood. 2007 Apr 15;109(8):3279-83. Epub 2006 Dec 7.\nPMID: 17158229 \nDOI 10.1182/blood-2006-08-040709\n

Vitamin K is a fat-soluble vitamin. The "K" is derived from the German word "koagulation." Coagulation refers to the process of blood clot formation. Vitamin K is essential for the functioning of several proteins involved in blood clotting (1). There are two naturally occurring forms of vitamin K

Effect of low dose vitamin K2 (MK-4) supplementation on bio-indices in postmenopausal Japanese women. Koitaya N, Ezaki J, Nishimuta M, Yamauchi J, Hashizume E, Morishita K, Miyachi M, Sasaki S, Ishimi Y. J Nutr Sci Vitaminol (Tokyo). 2009 Feb;55(1):15-21. PMID: 19352059 These results suggest that supplementation with 1.5 mg/d MK-4 accelerated the degree of OC gamma-carboxylation. The concentrations of serum lipids and other indices were not different between the groups at either intervention period. Thus, the additional intake of MK-4 might be beneficial in the maintenance of bone health in postmenopausal Japanese women.

Genetic and non-genetic correlates of vitamins K and D.\nShea MK, Benjamin EJ, Dupuis J, Massaro JM, Jacques PF, D'Agostino RB Sr, Ordovas JM, O'Donnell CJ, Dawson-Hughes B, Vasan RS, Booth SL.\nEur J Clin Nutr. 2007 Nov 21. [Epub ahead of print]\nPMID: 18030310 \ndoi: 10.1038/sj.ejcn\n\n

(NaturalNews) Adequate levels of vitamin K play in a central role in the development and maintenance of healthy bones in children, according to a study conducted by Dutch researchers from the Universities of Maastricht and Utrecht and published in the journal Clinical and Experimental Rheumatology.

Role of vitamin K2 in the treatment of postmenopausal osteoporosis. Iwamoto J, Takeda T, Sato Y. Curr Drug Saf. 2006 Jan;1(1):87-97. Review. PMID: 18690918