Optimal vitamin D status and serum parathyroid hormone concentrations in African American women
Optimal vitamin D status and serum parathyroid hormone concentrations in African American women
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DOI：
10.1093/ajcn/84.3.602
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发表时间：
2006-09-01
影响因子：
7.1
通讯作者：
Yeh, James K.
中科院分区：
文献类型：
--
作者：
Aloia, John F.;Talwar, Sonia A.;Yeh, James K.
背景资料：预防骨质疏松症的最佳维生素D状态已经从血清25-羟基维生素D [25（OH）D]浓度的检查中推断出来，低于该浓度，血清甲状旁腺激素（PTH）就会增加。本研究的目的是确定血清25（OH）D是否存在一个阈值，低于该阈值血清PTH升高，D高于这个阈值有较低的骨丢失率比人与25（OH）D低于threshold.Design：血清25（OH）D血清甲状旁腺素的关系进行了分析，在208名非洲裔美国妇女纵向研究3年。这些中年健康妇女被随机分配接受安慰剂或800 IU维生素D-3/d; 2年后，维生素D-3补充增加到2000 IU/d。两组都接受了钙补充剂，以确保足够的钙摄入量。一项系统的文献回顾发现了一个广泛的阈值，部分原因是不同的钙摄入量。结果：黄土图建议血清25（OH）D的断点在40和50 nmol/L之间。线性模型拟合数据，在44 nmol/L时显示样条结。启发式方法证实，当血清25（OH）D浓度> 40 nmol/L时，PTH下降不像血清25（OH）D浓度< 40 nmol/L时那样迅速。我们发现，25（OH）D浓度高于和低于40 nmol/L的人之间的骨丢失率没有显着差异。结论：虽然25（OH）D的阈值可以确定，我们建议，它不应该被用来推荐最佳的维生素D状态。
Background: Optimal vitamin D status for the prevention of osteoporosis has been inferred from examinations of the serum 25-hydroxyvitamn D [25(OH)D] concentration below which there is an increase in serum parathyroid hormone (PTH).Objective: The objectives of the study were to ascertain whether a threshold for serum 25(OH)D exists below which serum PTH increases and whether persons with 25(OH)D above this threshold have lower rates of bone loss than do persons with 25(OH)D below the threshold.Design: The relation of serum 25(OH)D to serum PTH was analyzed in 208 African American women studied longitudinally for 3 y. These healthy women in midlife were randomly assigned to receive placebo or 800 IU vitamin D-3/d; after 2 y, the vitamin D-3 supplementation was increased to 2000 IU/d. Both groups received calcium supplements to ensure an adequate calcium intake. A systematic literature review found a wide range of threshold values in part due to varied calcium intake.Results: A Loess plot suggested a breakpoint between 40 and 50 nmol/L for serum 25(OH)D. A line-line model was fitted to the data, and it showed a spline knot at 44 nmol/L. A heuristic approach verified that PTH does not decline as rapidly when the serum concentration of 25(OH)D is > 40 nmol/L as when it is < 40 nmol/L. We found no significant difference in rates of bone loss between persons with 25(OH)D concentrations above and below 40 nmol/L.Conclusion: Although a threshold for 25(OH)D can be identified we suggest that it should not be used to recommend optimal vitamin D status.