Wu Feitong, Laslett Laura L, Zhang Qian
Menzies Institute for Medical Research (F.W., L.L.L.), University of Tasmania, Hobart, Tasmania 7000, Australia; National Institute for Nutrition and Health (Q.Z.), Chinese Center for Disease Control and Prevention, Beijing 100050, China; and School of Public Health (F.W.), Anhui Medical University, Hefei 230032, Anhui, China.
J Clin Endocrinol Metab. 2015 Dec;100(12):4481-9. doi: 10.1210/jc.2015-2849. Epub 2015 Oct 14.
There is no consensus on the definition of vitamin D deficiency for bone health based on serum 25-hydroxyvitamin D (25OHD) levels.
Our objective was to determine whether thresholds exist for associations between 25OHD levels and bone outcomes and if low 25OHD levels have adverse effects on bone health.
This is a cross-sectional study.
This study included secondary school students in Beijing, China, aged 12-15 years.
We measured serum 25OHD; bone mineral density (BMD) of total body, hip, and lumbar spine (LS); serum PTH; bone alkaline phosphatase (BAP); and tartrate-resistant acid phosphatase 5b (TRAP5b) in 222 healthy adolescents (111 girls, 111 boys).
The prevalence of low 25OHD was 61% (<30 nmol/liter) and 97% (<50 nmol/liter) (mean 25OHD, 30 nmol/liter). Dietary calcium intake was low (294 and 307 mg/d for boys and girls, respectively). In girls, break-points for 25OHD (nmol/liter) were: total body BMD 20 (95% confidence interval [CI], 14-27), hip BMD 25 (17-34), LS BMD 22 (14-30), TRAP5b 37 (22-52), and PTH 31 (23-38). In boys, break-points were: total body BMD 39 (24-55), TRAP5b 33 (20-45), and PTH 35 (27-43); no break-points were identified for hip and LS BMD. No break-points were identified for BAP in either gender. Below these break-points, higher 25OHD is associated with increased total body BMD, reduced PTH, and TRAP5b, whereas above these break-points, no such relationship exists.
Vitamin D deficiency and insufficiency is common in healthy Chinese adolescents. Attaining serum 25OHD levels of more than 20-37 nmol/liter in girls and 33-39 nmol/liter in boys had positive influences on BMD and bone remodelling markers. However, estimates may be affected by low calcium intake and low serum 25OHD levels, with 97% of adolescents having levels below 50 nmol/liter.
基于血清25-羟基维生素D（25OHD）水平，对于骨骼健康的维生素D缺乏定义尚无共识。
我们的目的是确定25OHD水平与骨骼结局之间是否存在关联阈值，以及低25OHD水平是否对骨骼健康有不利影响。
这是一项横断面研究。
本研究纳入了中国北京年龄在12至15岁的中学生。
我们测量了222名健康青少年（111名女孩，111名男孩）的血清25OHD；全身、髋部和腰椎（LS）的骨密度（BMD）；血清甲状旁腺激素（PTH）；骨碱性磷酸酶（BAP）；以及抗酒石酸酸性磷酸酶5b（TRAP5b）。
25OHD水平低（<30 nmol/升）的患病率为61%，（<50 nmol/升）的患病率为97%（25OHD平均水平为30 nmol/升）。膳食钙摄入量低（男孩和女孩分别为294和307毫克/天）。在女孩中，25OHD（nmol/升）的断点为：全身骨密度20（95%置信区间[CI]，14 - 27），髋部骨密度25（17 - 34），腰椎骨密度22（14 - 30），TRAP5b 37（22 - 52），以及PTH 31（23 - 38）。在男孩中，断点为：全身骨密度39（24 - 55），TRAP5b 33（20 - 45），以及PTH 35（27 - 43）；未确定髋部和腰椎骨密度的断点。在任何性别中均未确定BAP的断点。低于这些断点时，较高的25OHD与全身骨密度增加、PTH和TRAP5b降低相关，而高于这些断点时，不存在这种关系。
维生素D缺乏和不足在健康的中国青少年中很常见。女孩血清25OHD水平达到20 - 37 nmol/升以上，男孩达到33 - 39 nmol/升以上，对骨密度和骨重塑标志物有积极影响。然而，估计值可能受到低钙摄入量和低血清25OHD水平的影响，97%的青少年水平低于50 nmol/升。
