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Value Assignment of Vitamin D Metabolites in Vitamin D Standardization Program (VDSP) Serum Samples



Karen W. Phinney, Johanna Camara, Susan Tai, Lane C. Sander, Stephen A. Wise, Linde A. De Grande, Linda M. Thienpont, Antonio M. Possolo, Blaza Toman, Christopher T. Sempos, J. M. Betz, Paul M. Coates


Assay variability has been cited as an obstacle to establishing optimal vitamin D exposure. As part of the Vitamin D Standardization Program (VDSP) effort to standardize the measurement of total 25(OH)D, value assignment of total 25(OH)D in 50 single donor serum samples was performed using two isotope-dilution LC-MS/MS methods. Both methods are recognized as reference measurement procedures (RMPs). These samples and their assigned values serve as the foundation for several aspects of the VDSP. To our knowledge, this is the first time that two RMPs have been used to assign values to such a large number of serum samples.
Journal of Aoac International


reference measurement procedure, standardization, vitamin D


Phinney, K. , Camara, J. , Tai, S. , Sander, L. , Wise, S. , De, L. , Thienpont, L. , Possolo, A. , Toman, B. , Sempos, C. , Betz, J. and Coates, P. (2017), Value Assignment of Vitamin D Metabolites in Vitamin D Standardization Program (VDSP) Serum Samples, Journal of Aoac International, [online], (Accessed May 28, 2024)


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Created June 16, 2017, Updated November 10, 2018