Haarburger D, Hoffman M, Erasmus R T, Pillay T S
Division of Chemical Pathology, Groote Schuur Hospital, University of Cape Town and Department of Chemical Pathology, University of Stellenbosch, Tygerberg Hospital, and National Health Laboratory Service, Cape Town, South Africa.
J Clin Pathol. 2009 Jun;62(6):567-9. doi: 10.1136/jcp.2008.062877. Epub 2009 Feb 12.
The aim of this study was to test the hypothesis that vitamin D deficiency is associated with abnormal levels of calcium and parathyroid hormone (PTH).
Vitamin D requests at a tertiary hospital in South Africa over 2 years were retrospectively analysed along with calcium and PTH levels.
Only when the 25-hydroxyvitamin D (25(OH)D) level dropped below 25 nmol/l, was there a significant rise in PTH. A subnormal 25(OH)D level was also not always related to hypocalcaemia, as more than half of patients with their 25(OH)D level below 25 nmol/l had calcium levels in the reference range. However, all patients with calcium levels below 1.8 mmol/l were shown to have vitamin D insufficiency.
Hypovitaminosis D may co-exist with a blunted PTH response. Therefore, assumptions about vitamin D status should not be made based on PTH and calcium values. 25(OH)D measurements should be requested when vitamin D deficiency is clinically suspected, irrespective of biochemical results.
本研究的目的是检验维生素D缺乏与钙及甲状旁腺激素（PTH）水平异常相关这一假设。
回顾性分析了南非一家三级医院2年间的维生素D检测申请以及钙和PTH水平。
仅当25-羟基维生素D（25(OH)D）水平降至25 nmol/l以下时，PTH才会显著升高。25(OH)D水平低于正常也并非总是与低钙血症相关，因为超过半数25(OH)D水平低于25 nmol/l的患者钙水平在参考范围内。然而，所有钙水平低于1.8 mmol/l的患者均显示存在维生素D不足。
维生素D缺乏症可能与PTH反应迟钝并存。因此，不应基于PTH和钙值来推断维生素D状态。当临床上怀疑维生素D缺乏时，无论生化结果如何，均应进行25(OH)D检测。
