Seamans Kelly M, Cashman Kevin D
Department of Food and Nutritional Sciences, University College Cork, Cork, Ireland.
Am J Clin Nutr. 2009 Jun;89(6):1997S-2008S. doi: 10.3945/ajcn.2009.27230D. Epub 2009 Apr 29.
Although serum 25-hydroxyvitamin D [25(OH)D] is the currently accepted vitamin D status marker of choice, use of other biomarkers or functional endpoints have been suggested.
The objective was to systematically review the effectiveness of 25(OH)D, parathyroid hormone (PTH), bone turnover markers, bone mineral density (BMD), and calcium absorption as biomarkers of vitamin D status.
Methods included a structured search on Ovid MEDLINE, EMBASE (Ovid), and Cochrane CENTRAL; rigorous inclusion/exclusion criteria; data extraction; quality assessment; meta-analysis; and meta-regression.
Thirty-six vitamin D supplementation randomized controlled trials (RCTs) and 4 before-after studies were included. Vitamin D supplementation significantly raised circulating 25(OH)D in all but one RCT, but the response was highly heterogeneous [weighted mean difference (WMD): 34.1 nmol/L; 95% CI: 28.9, 39.2; 32 RCTs; I2 = 97%). Vitamin D supplementation (without calcium) significantly lowered circulating PTH (WMD: -0.29 pmol/L; 95% CI: -0.56, -0.02; 11 RCTs; I2 = 29%), but this was not apparent in the presence of calcium supplementation. There was a suggestion that whole-body or lumbar spine BMD may be a useful biomarker in older people but not in adolescents. Bone turnover markers were not useful biomarkers of vitamin D status, but 4 before-after studies suggested that intestinal calcium absorption may respond to vitamin D status.
This systematic review confirmed that circulating 25(OH)D is a robust and reliable marker of vitamin D status. Further research is needed to clarify which population subgroups show responses of PTH, BMD, and/or calcium absorption in response to changes in vitamin D status.
尽管血清25-羟维生素D[25(OH)D]是目前公认的首选维生素D状态标志物，但也有人建议使用其他生物标志物或功能终点指标。
系统评价25(OH)D、甲状旁腺激素(PTH)、骨转换标志物、骨密度(BMD)和钙吸收作为维生素D状态生物标志物的有效性。
方法包括在Ovid MEDLINE、EMBASE(Ovid)和Cochrane CENTRAL上进行结构化检索；严格的纳入/排除标准；数据提取；质量评估；荟萃分析；以及荟萃回归分析。
纳入了36项维生素D补充随机对照试验(RCT)和4项前后对照研究。除一项RCT外，维生素D补充剂在所有试验中均显著提高了循环25(OH)D水平，但反应高度异质性[加权平均差(WMD)：34.1 nmol/L；95%可信区间(CI)：28.9，39.2；32项RCT；I2=97%]。维生素D补充剂(无钙)显著降低了循环PTH水平(WMD：-0.29 pmol/L；95%CI：-0.56，-0.02；11项RCT；I2=29%)，但在补充钙的情况下并不明显。有迹象表明，全身或腰椎骨密度可能是老年人有用的生物标志物，但对青少年则不然。骨转换标志物不是维生素D状态的有用生物标志物，但4项前后对照研究表明，肠道钙吸收可能对维生素D状态有反应。
本系统评价证实，循环25(OH)D是维生素D状态的可靠标志物。需要进一步研究以明确哪些人群亚组在维生素D状态发生变化时，其PTH、BMD和/或钙吸收会出现反应。
