Synthesis of 13C Labeled Vitamin D Metabolites for Their Use in LC-MS/MS: Valuable Tools for Cancer Research and Other Applications

Abstract

Background/aim: Simultaneous assessment of various vitamin D metabolites in human biofluids by liquid chromatography tandem mass spectrometry (LC-MS/MS) represents a new promising tool for the differential diagnosis of vitamin D-related diseases. Particularly, besides 25(OH)VD_2/3, low-abundant medicinally relevant vitamin D metabolites, such as 24,25(OH)₂VD_2/3, 1,25(OH)₂VD_2/3, and 1,24,25(OH)₃VD_2/3, along with their 3-epi-derivatives have to be considered.

Materials and methods: The assessment of these metabolites by LC-MS/MS requires the development of calibration and reference standards, that is, their labeling with multiple deuterium-, or even better, ¹³C- atoms.

Results: Overall, 10 ¹³C-labeled vitamin D metabolites have been chemically synthesized and obtained in good yield and high purity.

Conclusion: Access to a wide variety of ¹³C-labeled highly pure vitamin D metabolites enables the advancement of LC-MS/MS applications towards a better understanding of differential diagnosis of vitamin D-related diseases.

Keywords: Cancer prevention; LC-MS/MS assay development; vitamin D metabolites; vitamin D synthesis.