Dietary & non-dietary components of vitamin K metabolism

饮食

• 批准号: 6969060
• 负责人: SARAH Louise BOOTH
• 金额: $ 31.77万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-30 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6969060
• 关键词: age difference; blood lipoprotein transport; body composition; bone metabolism; clinical research; dietary supplements; human middle age (35-64); human old age (65+); human subject; lipid transport; nutrition related tag; photon absorptiometry; vitamin K; vitamin metabolism; young adult human (21-34)

DESCRIPTION (provided by applicant): Vitamin K has an emerging role in bone health. However, little is known about the vitamin K metabolism, particularly in regards to aging, and maintenance of bone mass. Such limited understanding about vitamin K metabolism currently impedes the ability to establish dietary recommendations for vitamin K, and interpret the results from recent clinical trials on vitamin K supplementation and bone health currently being conducted in primarily women of a narrow age group. The proposed study will be the first to assess the role of dietary and non-dietary factors that influence the response to measures of vitamin K status and bone turnover to vitamin K depletion and repletion in younger and older men and women. This study will also compare the absorption efficiency of vitamin K, relative to current vitamin K status. Men and women [21 younger (21-40y) and 21 older (60-80y)] will participate in a 65-d metabolic study, with a 5-d run-in period, followed by a 30 d dietary vitamin K restriction period (10 mu/ g/d), and ending with a 30 d dietary vitamin K supplementation period (500 mu g/d). Serial measurements of markers of vitamin K status (plasma phylloquinone, urinary Gla, serum %ucOC and plasma PIVKA-II) and bone turnover (serum osteocalcin and NTx) will provide information on their response to dietary manipulation of vitamin K for both age groups under identical controlled dietary conditions. A stable isotope tracer (deuterium-labeled vitamin K in collards) will be used to compare the absorption of vitamin K during a vitamin K-deplete state (21 d of dietary vitamin K depletion) to that of a vitamin K-replete state (21 d of dietary vitamin K repletion). Because vitamin K is transported in triglyceride-rich lipoproteins, which may vary among individuals due to differences in adiposity, measurement of body composition by DXA and plasma lipids (total and individual lipoproteins) will provide insight into the role of lipids in absorption and transport of vitamin K. The findings of the proposed study are critical for the interpretation of the epidemiologic and clinical data used to determine optimal intakes at which vitamin K may have a protective role in bone health.

描述（由申请人提供）：维生素K在骨骼健康中具有新兴作用。然而，关于维生素K代谢的知之甚少，尤其是在衰老和维持骨骼的方面。对维生素K代谢的理解有限，目前阻碍了为维生素K建立饮食建议的能力，并解释了目前主要是狭窄年龄段的妇女目前正在进行的有关维生素K补充和骨骼健康的临床试验的结果。拟议的研究将是第一个评估饮食和非肤色因素的作用的研究，这些因素影响了对年轻男性和年龄较大的男性和女性对维生素K状态和骨转换量对维生素K耗竭和充实的反应的反应。这项研究还将比较相对于当前的维生素K状态，维生素K的吸收效率。男性和女性[21岁（21-40y）和21岁（60-80y）]将参加65-D代谢研究，其中5-D rail-in-in-in-in-in-in-of-in-of-in-in-in-of-in-t-in-of-in-t-in-of-in-t-in-of-in-t-in-t-in-t-in-of-in-t-in-t-in-t-n of-5 d railimin K限制期（10 mu/g/d）（10 mu/g/d），并以30 d digary的维生素K补充期（500 mu g/d）结束。维生素K状态（血浆phylloquinone，尿中GLA，血清％UCOC和PLASMA PIVKA-II）和骨转换（血清骨质钙蛋白和NTX）的串行测量将提供有关其对两个相同的饮食饮食中的维生素K的反应的信息。将使用稳定的同位素示踪剂（胶囊中的氘标记的维生素K）来比较维生素K-链球菌期间维生素K的吸收（21 d的饮食维生素 k耗尽维生素K复发状态（饮食中维生素K的21 d）。因为维生素K在富含甘油三酸酯的脂蛋白中转运，由于脂肪差的差异，该脂蛋白可能会在个体之间有所不同，因此DXA和血浆脂质（总和总脂蛋白）对身体组成的测量（总和脂蛋白）将深入了解脂质在吸收和运输中的作用。确定维生素K可能在骨骼健康中具有保护作用的最佳摄入量。