National Centre for Epidemiology and Population Health, The Australian National University, Canberra, ACT, Australia.
Mol Nutr Food Res. 2010 Aug;54(8):1062-71. doi: 10.1002/mnfr.200900468.
The use of vitamin D testing has grown rapidly in the recent times as a result of increased interest in the role of vitamin D in health. Although the generally accepted measure of vitamin D status is circulating 25(OH)D concentration, there is little consensus on which assay method should be used. Commonly used assays include competitive protein-binding assay, RIA, enzyme immunoassay, chemiluminescence immunoassays, HPLC, and LC-MS/MS, each with its own advantages and disadvantages. However, there is significant interassay and interlaboratory variability in measurements. Our simulation of the published data showed that using a deficiency cut-point of 50 nmol/L, 57% of samples assessed using a chemiluminescence immunoassay were classified as deficient compared with 41% of samples assessed using LC-MS/MS; a 20% misclassification rate. Similar rates of misclassification were seen at 75 nmol/L. This has implications for clinical practice and decision limits for vitamin D supplementation, suggesting that cut-points should be assay specific rather than universal and that greater harmonization between laboratories is required. Newer assays using alternative biological samples to determine the circulating 25(OH)D have been proposed and advances in the genetics of vitamin D and the role of vitamin D-binding protein may improve future assay accuracy.
由于人们对维生素 D 在健康中的作用越来越感兴趣，维生素 D 检测在最近迅速普及。尽管循环 25（OH）D 浓度是公认的维生素 D 状态衡量标准，但对于应该使用哪种检测方法，目前还没有共识。常用的检测方法包括竞争性蛋白结合测定法、放射免疫测定法、酶免疫测定法、化学发光免疫测定法、高效液相色谱法和液相色谱-串联质谱法，每种方法都有其自身的优缺点。然而，在测量方面，存在着显著的检测内和实验室间变异性。我们对已发表数据的模拟表明，使用 50 nmol/L 的缺乏切点，与使用 LC-MS/MS 评估的 41%的样本相比，使用化学发光免疫测定法评估的样本中有 57%被归类为缺乏；存在 20%的错误分类率。在 75 nmol/L 时也观察到了类似的错误分类率。这对临床实践和维生素 D 补充的决策界限产生了影响，表明切点应该是特定于检测方法的，而不是通用的，并且需要在实验室之间进行更大的协调。已经提出了使用替代生物样本来确定循环 25（OH）D 的新检测方法，并且维生素 D 和维生素 D 结合蛋白的遗传学的进步可能会提高未来检测方法的准确性。
