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Tang, Jonathan 
ORCID: https://orcid.org/0000-0001-6305-6333, Washbourne, Christopher, Budnik-Zawilska, Milka, Piec, Isabelle ORCID: https://orcid.org/0000-0002-0648-1330 and Fraser, William
(2014)
Assessment of C3-Epi-25-Hydroxyvitamin D concentration in adult serum: LC-MS/MS determination using [2H3] 3-epi-25OHD3 internal standard and NIST traceable commercial 3-epi-25OHD calibrators.
In: American Society of Bone and Mineral Research, 2013-10-04 - 2013-10-07, Baltimore Convention Center.
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Abstract
Background: The C-3 Epimer of 25 Hydroxyvitamin D3 (3-Epi-25OHD3) is produced in the liver by the epimerisation pathway of 25-hydroxy vitamin D3. It differs from 25OHD3 in configuration of the hydroxyl group at the third carbon (C-3) position. Despite the fact that little is known regarding its clinical significance, concerns have been raised that isobaric interference may result in over-estimation of total 25OHD when measured by liquid chromatography tandem mass spectrometry (LC-MS/MS). Objective: The aim of the study was to assess the occurrence of 3-Epi-25OHD3 in adult serum samples. A LC-MS/MS technique was developed to resolve and quantify 3-Epi-25OHD3 from 25OHD3. The newly available NIST (SRM972a) traceable 3-Epi-25OHD commercial standards were used to ensure assay accuracy. Method: Serum was precipitated with zinc sulphate and acetonitrile containing [2H3]-3-epi-25OHD3 as internal standard. The extract was chromatographed using a 2.6µm 100 x 2.1mm I.D. solid core particle column. Mass detection and quantification were performed by positive electrospray ionization with MS/MS in multiple reaction monitoring mode. Results: The method was able to fully resolved 3-Epi-25OHD3 from 25OHD3. The intraassay CVs for the epimer were 6.3% and 4.1% at 25.4 and 62.1 nmol/L respectively; and interassay CVs were 8.3% and 6.5% at 27.6 and 63.2 nmol/L, respectively. In our sample cohort with 25OHD3 ranged between 3.4 – 165 nmol/L, 3-Epi-25OHD3 was detected in 91.9% of samples (mean = 3.8 nmol/L). No detectable 3-Epi-25OHD2 was found in our sample study. One patient sample had total 25OHD3 of 187 nmol/L that was shown to contain 141 nmol/L of 25OHD3 and 44 nmol/L of 3-Epi-25OHD3. This patient was receiving a high dose of vitamin D supplementation. Conclusion: Using [2H3]-3-epi-25OHD3 as internal standard and NIST aligned calibrators enabled us to obtain an accurate assessment of 3-epi-25OHD concentration in adult serum. Although the concentration of serum 3-epi-25OHD3 was found to be low the presence was observed in the majority of our samples. The findings in this study showed that 3-epi-25OHD3 contributed to the overestimation of 25OHD3 that could potentially resulted in misinterpretation of total vitamin D status.
| Item Type: | Conference or Workshop Item (Poster) |
|---|---|
| Additional Information: | J C Y Tang, C J Washbourne, I Piec, and W D Fraser 2014 Assessment of C3-Epi-25-Hydroxyvitamin D concentration in adult serum: LC-MS/MS determination using [2H3] 3-epi-25OHD3 internal standard and NIST traceable commercial 3-epi-25OHD calibrators. J Bone Miner Res 29 (Suppl 1). Available at http://www.asbmr.org/education/AbstractDetail?aid=c462af1d-cc58-44f4-9844-900f42a36ef1. Accessed September 07, 2014. |
| Faculty \ School: | Faculty of Medicine and Health Sciences > Norwich Medical School Faculty of Science |
| UEA Research Groups: | Faculty of Medicine and Health Sciences > Research Groups > Musculoskeletal Medicine Faculty of Medicine and Health Sciences > Research Centres > Metabolic Health |
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| Depositing User: | Pure Connector |
| Date Deposited: | 31 Oct 2014 12:58 |
| Last Modified: | 19 Oct 2023 03:58 |
| URI: | https://ueaeprints.uea.ac.uk/id/eprint/50534 |
| DOI: |
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