The measurement of vitamin D metabolites: part I—metabolism of vitamin D and the measurement of 25-hydroxyvitamin D

• Published in: Hormones (Athens, Greece) Vol. 19; no. 2; pp. 81 - 96
• Main Authors: Makris, Konstantinos, Sempos, Christopher, Cavalier, Etienne
• Format: Journal Article Web Resource
• Language: English
• Published: Cham Springer International Publishing 01-06-2020
• Subjects: 25-hydroxyvitamin D; Endocrinology; Human health sciences; Humans; Immunoassays; Laboratory medicine & medical technology; Liquid chromatography; Mass spectrometry; Medicine; Medicine & Public Health; Metabolic Diseases; Médecine de laboratoire & technologie médicale; Reference Standards; Review Article; Sciences de la santé humaine; Standardization; Vitamin D; Vitamin D - analogs & derivatives; Vitamin D - analysis; Vitamin D - metabolism; Vitamin D standardization program; Vitamin D; 25-hydroxyvitamin D; Standardization; Liquid chromatography; Mass spectrometry; Vitamin D standardization program; Immunoassays
• ISSN: 1109-3099; 2520-8721; 2520-8721
• DOI: 10.1007/s42000-019-00169-7

It has been more than 80 years since the discovery of vitamin D and its ability to cure rickets in children. Vitamin D is a secosteroid and comes in two distinct forms, vitamin D2 and vitamin D3. During the last 40 years, the synthesis and metabolism of vitamin D were elucidated and more than 50 metabolites of vitamin D have been discovered, though commercial measurement procedures have been developed for only a few of them. The clinical significance of vitamin D in calcium and phosphorus homeostasis is well appreciated. However, recent epidemiological data have indicated that it has several extra-skeletal physiologic actions which are still a matter of scientific debate. Both research findings and the debate around the interpretation of the research results have created increased interest in more measurements of vitamin D. With the ever growing family of measurable vitamin D metabolites and the measuring techniques comes a question: What metabolic product will provide the right answers and which is the best way to measure it. The right choice of analytical technique is connected with the question of which metabolite we aim to measure, what is its serum concentration, and the purpose of the measurement. The aim of the first part of this review is to provide a brief overview of vitamin D metabolism and a more detailed analysis of the existing methods and the status of standardization for the measurement of 25-hydroxyvitamin D.