biostudies-literatureWise SAIntramural NIH HHSNIH Office of the Director351-366https://www.ebi.ac.uk/biostudies/studies/S-EPMC8748290biostudies-literatureUnknown414(1)An interlaboratory comparison study was conducted by the Vitamin D Standardization Program (VDSP) to assess the performance of ligand binding assays (Part 2) for the determination of serum total 25-hydroxyvitamin D [25(OH)D]. Fifty single-donor samples were assigned target values for concentrations of 25-hydroxyvitamin D<sub>2</sub> [25(OH)D<sub>2</sub>], 25-hydroxyvitamin D<sub>3</sub> [25(OH)D<sub>3</sub>], 3-epi-25-hydroxyvitamin D<sub>3</sub> [3-epi-25(OH)D<sub>3</sub>], and 24R,25-dihydroxyvitamin D<sub>3</sub> [24R,25(OH)<sub>2</sub>D<sub>3</sub>] using isotope dilution liquid chromatography-tandem mass spectrometry (ID LC-MS/MS). VDSP Intercomparison Study 2 Part 2 includes results from 17 laboratories using 32 ligand binding assays. Assay performance was evaluated using mean % biasAnalytical and bioanalytical chemistryInterlaboratory comparison of 25-hydroxyvitamin D assays: Vitamin D Standardization Program (VDSP) Intercomparison Study 2 - Part 2 ligand binding assays - impact of 25-hydroxyvitamin D<sub>2</sub> and 24R,25-dihydroxyvitamin D<sub>3</sub> on assay performance.PMC8748290not applicableZ99 OD999999Beckert CCamara JESempos CTPham HSimpson CWise SAKhan DAWilliams ELCavalier EBatista MCNalin FSchultess JParker NPopp CLukas PKuszak AJTourneur CKilbane MBennett AFreeman JHahm GJansen EBurdette CQMerkel JMushtaq SVan Slooten GVillarreal ADurazo-Arvizu RAKaul RPease CTwomey PJfalseInterlaboratory comparison of 25-hydroxyvitamin D assays: Vitamin D Standardization Program (VDSP) Intercomparison Study 2 - Part 2 ligand binding assays - impact of 25-hydroxyvitamin D<sub>2</sub> and 24R,25-dihydroxyvitamin D<sub>3</sub> on assay performance.An interlaboratory comparison study was conducted by the Vitamin D Standardization Program (VDSP) to assess the performance of ligand binding assays (Part 2) for the determination of serum total 25-hydroxyvitamin D [25(OH)D]. Fifty single-donor samples were assigned target values for concentrations of 25-hydroxyvitamin D<sub>2</sub> [25(OH)D<sub>2</sub>], 25-hydroxyvitamin D<sub>3</sub> [25(OH)D<sub>3</sub>], 3-epi-25-hydroxyvitamin D<sub>3</sub> [3-epi-25(OH)D<sub>3</sub>], and 24R,25-dihydroxyvitamin D<sub>3</sub> [24R,25(OH)<sub>2</sub>D<sub>3</sub>] using isotope dilution liquid chromatography-tandem mass spectrometry (ID LC-MS/MS). VDSP Intercomparison Study 2 Part 2 includes results from 17 laboratories using 32 ligand binding assays. Assay performance was evaluated using mean % bias2022-01-01T00:00:00Z2022 Jan2025-04-19T18:08:20.699Z2025-04-19T18:08:20.699ZS-EPMC87482903443520710.1007/s00216-021-03577-0