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Prevalence of 25-hydroxyvitamin D₂ in Western New York: a 3-year study
Yan Victoria Zhang1, Moritz Stolla1, Tai C Kwong1
1Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Strong Memorial Hospital, Rochester, NY, United States.
Background:
We evaluated the distribution of 25OH-D2 and 25OH-D3 in a general patient population in Western New York to provide insights into how common detectable vitamin D2 is among samples from a general patient population.
Methods:
Serum 25OH-D2 and 25OH-D3 results measured by LC-MS/MS from June 2009 to December 2012 were retrospectively analyzed.
Results:
A total of 266,269 serum tests were included for analysis. The percentage of tests with 25OH-D2 levels above the assay limit of quantitation (LoQ) decreased from 32% to 17% over the course of the study period. The percentage of tests with 25OH-D2 levels higher than those of 25OH-D3 decreased from 21% to 12%. Sixty-seven percent of the test results with 25OH-D2 levels above the LoQ had serum concentrations of 25OH-D2 higher than those of 25OH-D3.
Conclusion:
Prevalence of tests with quantifiable 25OH-D2 decreased over time and yet 17% of them still had detectable levels of 25OH-D2, 67% of which had 25OH-D2 levels higher than 25OH-D3. To achieve accurate 25-hydroxyvitamin D measurement, clinical laboratories should assess the accuracy of their assays, and if necessary, determine the local prevalence of 25OH-D2 to determine if mass spectrometry is the platform of choice to assess vitamin D deficiency.
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