Sato K A, Gray R W, Lemann J
J Lab Clin Med. 1982 Mar;99(3):325-30.
Patients with the nephrotic syndrome may exhibit low serum 25-OH-D concentrations. We developed a method for isolation of 25-OH-D from urine, with measurement by competitive binding assay. Daily urinary 25-OH-D excretion in healthy subjects averaged 0.17 +/- 0.15 nmol/day. Among nephrotic patients, urinary 25-OH-D excretion ranged from 0.27 to 10 nmol/day, in direct relation to the severity of proteinuria (r=0.76) and averaged 3.7 +/- 3.5 nmol/day. The 25-OH-D in the urine of nephrotic patients was unconjugated, implying that it was excreted with the serum VDBG, which has been shown to have a molecular weight and isoelectric point similar to that of albumin. We conclude that low serum 25-OH-D concentrations among nephrotic patients are principally the result or urinary losses of steroid. (J Lab Clin Med 99:325, 1982.)
肾病综合征患者可能会出现血清25-羟基维生素D浓度降低的情况。我们开发了一种从尿液中分离25-羟基维生素D的方法，并通过竞争性结合测定法进行测量。健康受试者每日尿25-羟基维生素D排泄量平均为0.17±0.15 nmol/天。在肾病患者中，尿25-羟基维生素D排泄量在0.27至10 nmol/天之间，与蛋白尿严重程度直接相关（r = 0.76），平均为3.7±3.5 nmol/天。肾病患者尿液中的25-羟基维生素D未结合，这意味着它与血清维生素D结合球蛋白一起排泄，血清维生素D结合球蛋白的分子量和等电点已被证明与白蛋白相似。我们得出结论，肾病患者血清25-羟基维生素D浓度低主要是类固醇经尿液流失的结果。（《实验室与临床医学杂志》99:325, 1982年）
