The National Institute of Standards and Technology (NIST), in collaboration with the National Institutes of Healths Office of Dietary Supplements (NIH-ODS) has developed a Standard Reference Material (SRM) for the determination of 25-hydroxyvitamin D [25(OH)D] in serum. SRM 972 Vitamin D in Serum consists of four serum pools with different levels of vitamin D metabolites and has certified and reference values for 25(OH)D2, 25(OH)D3, and 3-epi-25(OH)D3. Value assignment of this SRM was accomplished using a combination of three isotope-dilution mass spectrometry approaches, with measurements performed at NIST and at the Centers for Disease Control and Prevention (CDC). Chromatographic resolution of the 3-epimer of 25(OH)D3 proved to be essential for accurate determination of this metabolite.
Citation: Analytical Chemistry
Pub Type: Journals
epimer, isotope dilution, mass spectrometry, reference material, vitamin D