Bach A U, Anderson S A, Foley A L, Williams E C, Suttie J W
Department of Nutritional Sciences, College of Agricultural and Life Sciences, University of Wisconsin-Madison 53706, USA.
Am J Clin Nutr. 1996 Dec;64(6):894-902. doi: 10.1093/ajcn/64.6.894.
Vitamin K is required to convert specific glutamyl residues in a limited number of proteins to gamma-carboxyglutamyl residues. The response of various measures of vitamin K insufficiency to the administration of 1 mg/d of the vitamin K antagonist warfarin was studied in two groups of nine older (55-75 y) or younger (20-28 y) subjects. The most consistent and extensive alteration was an increase in the concentration of serum under-gamma-carboxylated osteocalcin followed by increased immunochemical detection of plasma under-gamma-carboxylated prothrombin (PIVKA-II), and by a decreased urinary excretion of gamma-carboxyglutamic acid. Plasma concentrations of prothrombin were altered by this treatment but prothrombin times, factor VII activity, prothrombin F-1 x 2 concentrations, and a less sensitive assay for under-gamma-carboxylated prothrombine were not. The concentration of serum under-gamma-carboxylated osteocalcin was lower when subjects consumed 1 mg vitamin K/d than when they consumed their normal diet.
维生素K是将有限数量蛋白质中的特定谷氨酰残基转化为γ-羧基谷氨酰残基所必需的。在两组各9名年龄较大（55 - 75岁）或年龄较小（20 - 28岁）的受试者中，研究了维生素K拮抗剂华法林以1毫克/天的剂量给药后，各种维生素K不足指标的反应。最一致且广泛的变化是血清中未羧化骨钙素浓度升高，其次是血浆中未羧化凝血酶原（PIVKA-II）的免疫化学检测增加，以及γ-羧基谷氨酸的尿排泄减少。凝血酶原的血浆浓度因这种治疗而改变，但凝血酶原时间、因子VII活性、凝血酶原F-1 x 2浓度以及对未羧化凝血酶原的较不敏感检测未受影响。当受试者每天摄入1毫克维生素K时，血清中未羧化骨钙素的浓度低于他们正常饮食时的浓度。
