An evaluation of automated methods for measurement of serum 25-hydroxyvitamin D

Clin Biochem. 2009 Oct;42(15):1549-56. doi: 10.1016/j.clinbiochem.2009.07.013. Epub 2009 Jul 21.


Objectives: To compare two new automated assays with the well-established reference method, DiaSorin radioimmunoassay (RIA), for quantitation of serum total 25-hydroxyvitamin D [25(OH)D].

Methods: 25(OH)D from human sera (n=158) was measured using DiaSorin RIA and two automated platforms, DiaSorin "LIAISON 25 OH Vitamin D TOTAL", and Roche Modular "Vitamin D3 (25-OH)". Methods were compared by regression and Bland-Altman analyses.

Results: DiaSorin LIAISON demonstrated a stronger correlation (r=0.918) and better agreement (bias=-0.88 nmol/L) with DiaSorin RIA than the Roche Modular assay (r=0.871, bias=-2.55 nmol/L). Precision ranges (CV%) for the RIA, LIAISON, and Roche Modular assays, respectively, were: within run (6.8-12.9%, 2.8-8.1%, and 1.9-5.5%), and total precision (7.4-14.5%, 7.3-17.5%, and 7.6-14.5%).

Conclusion: DiaSorin LIAISON displayed the best correlation and agreement with DiaSorin RIA. The DiaSorin LIAISON 25 OH Vitamin D TOTAL assay is an accurate and precise automated tool for serum total 25(OH)D determination.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Binding, Competitive
  • Humans
  • Luminescent Measurements / instrumentation
  • Luminescent Measurements / methods*
  • Quality Control
  • Radioimmunoassay / instrumentation
  • Radioimmunoassay / methods*
  • Regression Analysis
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood


  • Vitamin D
  • 25-hydroxyvitamin D