A high phylloquinone intake is required to achieve maximal osteocalcin γ-carboxylation
A high phylloquinone intake is required to achieve maximal osteocalcin γ-carboxylation
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DOI：
10.1093/ajcn/76.5.1055
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发表时间：
2002-11-01
影响因子：
7.1
通讯作者：
Suttie, JW
中科院分区：
文献类型：
--
作者：
Binkley, NC;Krueger, DC;Suttie, JW
背景：膳食维生素K通常不足以使血清骨钙素γ-羧化最大化。叶绿醌补充增加骨钙素γ-carboxylation;然而，所需的量，以最大限度地提高羧化是unknowed.Objective：这项研究评估的能力，各种剂量的叶绿醌（维生素K-1），以促进骨钙素γ-carboxylation.Design：健康的成年人年龄在19-36 y参加了2个子studies。在最初的剂量探索研究（子研究A），6名妇女和4名男子接受安慰剂每天1周，然后叶绿醌每天3周：500，1000和2000微克，在第2，3和4周，分别。在基线和每周补充后测量骨钙素和低羧化骨钙素。随后，为了进一步描述骨钙素对不同剂量维生素K-1的γ-羧化反应，58名女性和42名男性被随机分配接受安慰剂或叶绿醌补充剂（250、375、500和1000 μ g/d），持续2周（子研究B）。结果：在亚研究A中，加入叶绿醌后，%ucOC降低（P < 0.0001），1000和2000 μg组降低幅度大于500 μg组（P < 0.05）。在子研究B中，第1周时所有补充组的%ucOC均降低（趋势P < 0.0001），并持续至第2周。补充叶绿醌可降低%ucOC，且呈依赖性; 250 μg组与安慰剂组、1000 μ g组与500 μg组之间的%ucOC存在显著差异，但250、375和500 μg组之间无显著差异。结论：每日叶绿醌摄入量≥ 1000 μg可使γ-羧酸循环骨钙素达到最大。
Background: Dietary vitamin K is usually inadequate to maximize serum osteocalcin gamma-carboxylation. Phylloquinone supplementation increases osteocalcin gamma-carboxylation; however, the amount required to maximize carboxylation is not known.Objective: This study assessed the ability of various doses of phylloquinone (vitamin K-1) to facilitate osteocalcin gamma-carboxylation.Design: Healthy adults aged 19-36 y participated in 2 substudies. In an initial dose-finding study (substudy A), 6 women and 4 men received a placebo daily for 1 wk and then phylloquinone daily for 3 wk: 500, 1000, and 2000 mug during weeks 2, 3, and 4, respectively. Osteocalcin and undercarboxylated osteocalcin were measured at baseline and after each week of supplementation. Subsequently, to further delineate the gamma-carboxylation response of osteocalcin to various doses of vitamin K-1 58 women and 42 men were randomly assigned to receive placebo or phylloquinone supplementation (250, 375, 500, and 1000 mug/d) for 2 wk (substudy B). The percentage of undercarboxylated osteocalcin (%ucOC) was measured at baseline and weeks 1 and 2.Results: In substudy A, %ucOC decreased with phylloquinone supplementation (P < 0.0001); a greater reduction was observed with 1000 and 2000 μg than with 500 μg (P < 0.05). In substudy B, %ucOC decreased in all supplemented groups by week 1 (P for the trend < 0.0001), which was sustained through week 2. Phylloquinone supplementation decreased %ucOC do se-dependently; %ucOC was significantly different between the 250-μg and the placebo groups and between the 1000- and 500-μg groups but not between the 250, 375-, and 500-μg groups.Conclusion: A daily phylloquinone intake of ≈1000 μg is required to maximally γ-carboxylate circulating osteocalcin.