title: Rapid analysis of 25-hydroxyvitamin D(2) and D(3) by liquid chromatography-tandem mass spectrometry and association of vitamin D and parathyroid hormone concentrations in healthy adults.
abstract: Measurement of 25-hydroxyvitamin D (25OH-vitD) is used to assess vitamin D status. We developed a high-sensitivity measurement method for 25OH-vitD and assessed the relationship between 25OH-vitD and parathyroid hormone (PTH) in healthy adults. Aliquots (100 microL) of serum were spiked with internal standard, proteins were precipitated, and samples were analyzed by liquid chromatography-tandem mass spectrometry using 2-dimensional chromatographic separation. Total imprecision was less than 10%, and the limit of quantitation was 1.0 ng/mL. We determined the distribution of concentrations of 25OH-vitD(2) and 25OH-vitD(3) in healthy adults using samples collected during winter and summer and evaluated the association between 25OH-vitD and PTH. The difference between median concentrations of 25OH-vitD in samples collected during winter and summer was 11 ng/mL (27 nmol/L). Statistically significant differences in concentrations of PTH were observed between groups of samples with 25OH-vitD less than 11 (27 nmol/L) and 11 to 15 ng/mL (27-37 nmol/L) and between groups with 25 to 30 (62-75 nmol/L) and more than 40 ng/mL (100 nmol/L). Among the advantages of this method are its high sensitivity and specificity.
authors.affiliation: ARUP Institute for Clinical and Experimental Pathology, University of Utah, Salt Lake City, USA.
authors.forename: Mark M
authors.initials: MM
authors.lastname: Kushnir
authors.forename: Julie A
authors.initials: JA
authors.lastname: Ray
authors.forename: Alan L
authors.initials: AL
authors.lastname: Rockwood
authors.forename: William L
authors.initials: WL
authors.lastname: Roberts
authors.forename: Sonia L
authors.initials: SL
authors.lastname: La'ulu
authors.forename: JoDell E
authors.initials: JE
authors.lastname: Whittington
authors.forename: A Wayne
authors.initials: AW
authors.lastname: Meikle
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood*; D000328:Adult; D000368:Aged; D002112:Calcifediol / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012621:Seasons; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol