Comparison of four current 25-hydroxyvitamin D assays

Objectives: The performance of recently developed vitamin D total assays (ADVIA Centaur and Elecsys) was compared to that of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and LIASON 25-OH Vitamin D total assays. Design and methods: A total of 157 clinical samples and standard reference material (SRM) 972 were analyzed. Results: The correlations of LC-MS/MS with the three immunoassays were acceptable. However, compared to LC-MS/MS, LIAISON and ADVIA Centaur showed negative bias, and Elecsys showed positive bias. There was a lack of agreement among the four methods with only LC-MS/MS results close to the certified values of SRM 972. The prevalence of vitamin D insufficiency (<50 nmol/L) was higher with ADVIA Centaur (51.6%) and LIAISON (52.2%) and lower with Elecsys (37.6%), compared with that of LC-MS/MS (44.6%). Conclusion: The new, automated total vitamin D assays show acceptable correlation with LC-MS/MS, and could be used in routine laboratories. However, standardization of vitamin D assays and consideration of assay-specific decision limits should be addressed. (C) 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.