title: UPLC-MS/MS Determination of Deuterated 25-Hydroxyvitamin D (d3-25OHD3) and Other Vitamin D Metabolites for the Measurement of 25OHD Half-Life.
abstract: Plasma 25-hydroxyvitamin D (25OHD) half-life (25OHDt1/2) is a dynamic marker of vitamin D metabolism that can be used to assess vitamin D expenditure and help inform vitamin D requirements. Our group recently established an approach to determine the 25OHDt1/2as an alternative biomarker of 25OHD expenditure in humans. The approach uses a small oral dose of stable isotope labeled 25OHD3[3-2H-25OHD3(6,19,19-d3)] (d3-25OHD3) (tracer), which is distinguishable from endogenous 25OHD by liquid chromatography tandem-mass spectrometry (LC-MS/MS). We report here the method, which relies on protein precipitation, purification with solid phase extraction, derivatization with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), and determination of the compounds by isotope-dilution UPLC-MS/MS. The method proved to be rapid and sensitive (LOQ 0.2 nmol/L) for the quantification of this tracer as well as the other vitamin D metabolites: 25OHD3, 25OHD2, and 24,25(OH)2D3in human plasma.
authors.affiliation: MRC Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK. scimaar@yahoo.com.
authors.forename: Shima
authors.initials: S
authors.lastname: Assar
authors.affiliation: MRC Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK.
authors.forename: Inez
authors.initials: I
authors.lastname: Schoenmakers
authors.affiliation: MRC Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK.
authors.forename: Albert
authors.initials: A
authors.lastname: Koulman
authors.affiliation: MRC Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK.
authors.forename: Ann
authors.initials: A
authors.lastname: Prentice
authors.affiliation: MRC Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge, CB1 9NL, UK.
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Jones
mesh_terms: D015415:Biomarkers; D002853:Chromatography, Liquid / Q000379:methods / Q000592:standards; D003903:Deuterium; D006801:Humans; D007553:Isotope Labeling; D055442:Metabolome; D055432:Metabolomics / Q000379:methods / Q000592:standards; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry / Q000379:methods / Q000592:standards; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood*
chemical_list: D015415:Biomarkers; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D003903:Deuterium
keywords: 24,25(OH)2D3; 25OHD2; 25OHD3; Biomarker; Liquid chromatography mass spectrometry; PTAD derivatization; Stable isotope of 25OHD3; Vitamin D