Licht-im-Terrarium: Literaturdatenbank
Licht-im-Terrarium: Literaturdatenbank |
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Hollis, B. W. (2011). Chapter 47 - detection of vitamin d and its major metabolites. In D. Feldman, W. J. Pike & J. S. Adams (Eds), Vitamin D (Third Edition) Third Edition ed.(pp. 823–844). San Diego: Academic Press. Added by: Sarina (2016-10-21 10:11:21) |
| Resource type: Book Article DOI: http://dx.doi.org/10.1016/B978-0-12-381978-9.10047-2 ID no. (ISBN etc.): 978-0-12-381978-9 BibTeX citation key: Hollis2011 View all bibliographic details  |
Categories: Englisch = English Creators: Adams, Feldman, Hollis, Pike Publisher: Academic Press (San Diego) Collection: Vitamin D (Third Edition) |
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The field of vitamin D assay technology has progressed significantly over the past four decades. Further, the clinical utility of these measurements has moved from esoteric into mainstream clinical diagnosis. This movement has been fueled by the realization that vitamin D is involved in bodily systems beyond skeletal integrity. The clinical assay techniques for circulating 25(OH)D and 1,25(OH)2D have progressed away from competitive protein-binding assays (CPBAs) that utilize tritium reporters to radioimmunoassays (RIAs) that utilize both {I125} and chemiluminescent reporters. These advances have allowed direct serum analysis of 25(OH)D in an automated format that provides a huge sample throughput. Detection of circulating 25(OH)D can also be achieved utilizing direct high-performance liquid chromatographic (HPLC) or liquid chromatography coupled with mass spectrometry (LC-MS) techniques. These methods are accurate, however, they require expensive equipment and restrict sample throughput in the large clinical laboratory. Direct serum detection of 1,25(OH)2D is unlikely to occur for many reasons as a sample prepurification will always be required. These advances will allow 25(OH)D to be detected in an accurate, rapid fashion to meet the clinical demands emerging. Publisher Summary Vitamin D is a 9,10-secosteroid and is treated as such in the numbering of its carbon skeleton. Vitamin D occurs in two distinct forms—vitamin {D2} and vitamin D3. Metabolic activation of vitamin D is achieved through hydroxylation reactions at both carbon 25 of the side chain and, subsequently, carbon 1 of the A ring. Metabolic inactivation of vitamin D takes place primarily through a series of oxidative reactions at carbons 23, 24, and 26 of the side chain of the molecule. These metabolic activations and inactivations are well characterized and result in a plethora of vitamin D metabolites. Of all the compounds, only four, vitamin D, 25-hydroxyvitamin D (25(OH)D), 24,25-dihydroxyvitamin D (24,25(OH)2D), and 1,25- dihydroxyvitamin D (1,25(OH)2D) have been extensively quantitated, and to date only two of those, namely, 25(OH)D and 1,25(OH)2D, provide any clinically relevant information. However, the quantitation of vitamin D and 24,25(OH)2D can provide important information in a research environment. This calls for further research.
Added by: Sarina |