Effect of Vitamin K on Age-Related Bone Loss

描述（从申请人的描述扫描）：膳食摄入量 成人的维生素K含量很低。这些摄入量不支持完整的 骨钙素的羧化，骨中的维生素K依赖性蛋白，和 短期膳食维生素K缺乏可能会增加成年人的骨转换。 流行病学证据表明， 维生素K营养和老年男性和女性与年龄相关的骨质流失。然而 目前尚不清楚这些维生素K营养标志物是否是 在这些研究中，普遍的总体营养状况较差。而且 长期补充维生素K对骨矿物质密度（BMD）和 尚未检查骨转换。在为期3年的双盲安慰剂研究中， 对照试验，我们建议研究维生素K补充剂的作用 (500 450名男性的股骨颈BMD和骨转换标志物， 60-80岁的妇女。所有参与者还将接受钙和 维生素D补充剂，除了多种维生素，以防止任何潜在的 骨质流失与这些营养素的饮食不足有关。我们将 测量血浆维生素K浓度和羧基化不足百分比 骨钙素（维生素K状态的标志物）、血清骨钙素和胶原蛋白 1型交联N-端肽（骨转换标志物）和髋部BMD， 以及在出生后1、6、12、24和36个月时的脚跟、脊柱和全身。 维生素K补充剂血浆25-羟基维生素D和1， 25-二羟维生素D浓度和尿钙将在 相同的时间点将在该评估中用作Covanate。其他 在研究过程中收集的协变量包括年龄， 人体测量数据、体力活动、使用的药物、吸烟和饮食 能量、蛋白质、酒精和咖啡因的摄入量。拟议的试验提供了一个 确定补充维生素K是否会减少的独特机会 老年男性和女性中与年龄相关的骨质流失，高于 补充钙和维生素D。

DESCRIPTION (Scanned from the applicant's description): Usual dietary intakes of vitamin K among adults are low. These intakes do not support complete carboxylation of osteocalcin, a vitamin K-dependent protein in bone, and short-term dietary vitamin K deficiency may increase bone turnover in adults. Epidemiological evidence has shown associations between biochemical markers of vitamin K nutrition and age-related bone loss in elderly men and women. However it is not known if these markers of vitamin K nutrition are indicators of generalized poor total nutritional status in these studies. Furthermore, the impact of long-term vitamin K supplementation on bone mineral density (BMD) and bone turnover has not been examined. In a 3-year, double-blind, placebo controlled trial, we propose to study the effect of vitamin K supplementation (500 ug/d on femoral neck BMD and markers of bone turnover in 450 men and women, aged 60-80 years. All participants will also be receiving calcium and vitamin D supplements, in addition to a multivitamin, to prevent any potential bone loss associated with dietary inadequacy of these nutrients. We will measure plasma vitamin K concentrations and percent undercarboxylated osteocalcin (markers of vitamin K status), serum osteocalcin and collagen Type-1-crosslink N-telopeptides (markers of bone turnover) and BMD of the hip, as well as the heel, spine and total body at 1, 6, 12, 24, and 36 months of vitamin K supplementation. Plasma 25-hydroxyvitamin D and 1, 25-dihydroxyvitamin D concentrations and urinary calcium will be measured at the same time points to be used as covanates in this assessment. Other covariates collected through the course of the study include age, anthropometric data, physical activity, medication used, smoking, and dietary intakes of energy, protein, alcohol and caffeine. The proposed trial provides a unique opportunity to determine if supplemental vitamin K will reduce age-related bone loss in elderly men and women, above that achieved by supplemental calcium and vitamin D alone.