Full-scan mass spectral evidence for 3-epi-25-hydroxyvitamin D₃ in serum of infants and adults

Abstract

This preliminary finding suggests that the prevalence of 3-epi-25OHD₃ in serum of infants is considerable, and that even in adults the concentrations of this form should not be neglected.

State-of-the-Art Vitamin D Assays: A Comparison of Automated Immunoassays with Liquid Chromatography–Tandem Mass Spectrometry Methods

“…Initial reports suggested that this issue is confined to children younger than 1 year (25 ). However, a recent study by Stepman et al showed that even in adults 3-epi forms are present in variable concentrations and may represent up to 17% of total 25OH-D (26 ). A limitation of the LC-MS/MS methods used in this study is that they did not separate the epimer forms.…”

Automated Competitive Protein‐Binding Assay for Total 25‐OH Vitamin D, Multicenter Evaluation and Practical Performance

“…The Elecsys assay is standardized against a modified version of the LC-MS/MS method published by Vogeser et al (22) with traceability to the reference material NIST SRM 2972, which consists of two ethanolic solutions of either 25-OHD2 or 25-OHD3 that are used to calibrate chromatographic methods (5,21,30). In addition, the performance of the in house LC-MS/MS was monitored by using NIST SRM 972 (vitamin D in human serum), which is the first certified reference material for quality-control use with officially assigned target values (5,18,19,30). Hence, the calibration of the Elecsys assay is traceable to the NIST standards described above.…”

Fast Separation of 25-Hydroxyvitamin D3 from 3-Epi-25-Hydroxyvitamin D3 in Human Serum by Liquid Chromatography–Tandem Mass Spectrometry: Variable Prevalence of 3-Epi-25-Hydroxyvitamin D3 in Infants, Children, and Adults

“…A limitation of most LC-MS/MS methods is the potential interference from coeluting isomeric compounds having identical elemental composition but different structure, leading to overestimation of true 25(OH)D concentrations. Of particular interest is the C3 epimer of 25(OH)D, 3-epi-25(OH)D, which can be present at relatively high concentrations in sera from infants, but can also be found in sera from adults, albeit at lower concentrations (1,2 Calibrators, controls, and patient sera were treated with sodium hydroxide to release vitamin D metabolites from the binding protein before protein precipitation. Subsequent off-line solid-phase extraction was followed by chromatographic separation performed by use of a pentafluorophenyl-propyl (PFP) column (Acquity UPLC CSH™ fluoro-phenyl 1.7 m, 2.1 ϫ 100 mm; Waters).…”