Adams Jamie, Pepping Joseph
Castle Medical Center, Kailua, HI 96814, USA.
Am J Health Syst Pharm. 2005 Aug 1;62(15):1574-81. doi: 10.2146/ajhp040357.
The role of vitamin K in the prevention and treatment of osteoporosis and arterial calcification is examined.
Vitamin K is essential for the activation of vitamin K-dependent proteins, which are involved not only in blood coagulation but in bone metabolism and the inhibition of arterial calcification. In humans, vitamin K is primarily a cofactor in the enzymatic reaction that converts glutamate residues into gamma-carboxyglutamate residues in vitamin K-dependent proteins. Numerous studies have demonstrated the importance of vitamin K in bone health. The results of recent studies have suggested that concurrent use of menaquinone and vitamin D may substantially reduce bone loss. Menaquinone was also found to have a synergistic effect when administered with hormone therapy. Several epidemiologic and intervention studies have found that vitamin K deficiency causes reductions in bone mineral density and increases the risk of fractures. Arterial calcification is an active, cell-controlled process that shares many similarities with bone metabolism. Concurrent arterial calcification and osteoporosis have been called the "calcification paradox" and occur frequently in postmenopausal women. The results of two dose-response studies have indicated that the amount of vitamin K needed for optimal gamma-carboxylation of osteocalcin is significantly higher than what is provided through diet alone and that current dosage recommendations should be increased to optimize bone mineralization. Few adverse effects have been reported from oral vitamin K.
Phytonadione and menaquinone may be effective for the prevention and treatment of osteoporosis and arterial calcification.
研究维生素K在骨质疏松症和动脉钙化的预防及治疗中的作用。
维生素K对于维生素K依赖蛋白的激活至关重要，这些蛋白不仅参与血液凝固，还参与骨代谢及抑制动脉钙化。在人类中，维生素K主要是一种酶促反应中的辅助因子，该反应将维生素K依赖蛋白中的谷氨酸残基转化为γ-羧基谷氨酸残基。众多研究已证明维生素K对骨骼健康的重要性。近期研究结果表明，同时使用甲萘醌和维生素D可能会大幅减少骨质流失。还发现甲萘醌与激素疗法联合使用时有协同作用。多项流行病学和干预研究发现，维生素K缺乏会导致骨矿物质密度降低并增加骨折风险。动脉钙化是一个活跃的、细胞控制的过程，与骨代谢有许多相似之处。动脉钙化和骨质疏松症同时出现被称为“钙化悖论”，且在绝经后女性中经常发生。两项剂量反应研究结果表明，骨钙素最佳γ-羧化所需的维生素K量显著高于仅通过饮食提供的量，并且目前的剂量建议应增加以优化骨矿化。口服维生素K报告的不良反应很少。
叶绿醌和甲萘醌可能对骨质疏松症和动脉钙化的预防及治疗有效。
