Osteoporosis International

, Volume 21, Issue 6, pp 1047–1051

Measurement uncertainty of 25-OH vitamin D determination with different commercially available kits: impact on the clinical cut offs

  • E. Cavalier
  • E. Rozet
  • R. Gadisseur
  • A. Carlisi
  • M. Monge
  • J.-P. Chapelle
  • P. Hubert
  • J.-C. Souberbielle
  • P. Delanaye
Short Communication

DOI: 10.1007/s00198-009-1052-5

Cite this article as:
Cavalier, E., Rozet, E., Gadisseur, R. et al. Osteoporos Int (2010) 21: 1047. doi:10.1007/s00198-009-1052-5

Abstract

Summary

Due to “measurement uncertainty”, the “true” 25-OH vitamin D (25(OH)D) of a patient (whatever the commercially available assay tested) will be >80 nmol/L if its measured concentration is >100 nmol/L. Thus, if a physician considers that a normal VTD status is a 25(OH)D level ≥80 nmol/L, he should ensure that the patient’s results are ≥100 nmol/L.

Introduction

Many experts recommend that serum levels of 25(OH)D should be above a lower normal limit of 75–80 nmol/L. However, the value delivered by laboratories is only an estimation of the “true” value due to “measurement uncertainty.” When using a cut off, measurement uncertainty around the cut off is important because therapeutic actions may differ if the measured value is below or above the limit. We aimed to establish the “measurement uncertainty” at different levels of concentration for several commercially available 25(OH)D analytical techniques.

Methods

We constituted three pools of serum with different 25(OH)D concentrations. Each pool was assayed in triplicate during 5 days with the DiaSorin RIA, Liaison, Elecsys, and Chromsystems-HPLC assays.

Results

We report a relatively high “measurement uncertainty” for the measurement of 25(OH)D for the four different techniques: the mean relative uncertainties, all techniques confounded were 19.4%, 16.0%, and 11.3% for pool 1 (35.3 nmol/L), pool 2 (79.5 nmol/L), and pool 3 (126.1 nmol/L), respectively.

Conclusions

Our results show that, whatever the assay, the “true” 25(OH)D of a patient will be >80 nmol/L if its measured concentration is >100 nmol/L. In other words, if a physician considers that a normal VTD status is defined by a 25(OH)D level ≥80 nmol/L, he should ensure that the patients present a 25(OH)D ≥100 nmol/L.

Keywords

25-OH vitamin D Hyperparathyroidism Immunoassay Measurement uncertainty Target concentration 

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2009

Authors and Affiliations

  • E. Cavalier
    • 1
  • E. Rozet
    • 2
  • R. Gadisseur
    • 1
  • A. Carlisi
    • 1
  • M. Monge
    • 3
  • J.-P. Chapelle
    • 1
  • P. Hubert
    • 2
  • J.-C. Souberbielle
    • 4
  • P. Delanaye
    • 5
  1. 1.Department of Clinical ChemistryUniversity Hospital of LiègeLiègeBelgium
  2. 2.Department of Analytical ChemistryUniversity of LiègeLiègeBelgium
  3. 3.Laboratoire Pasteur-Cerba, Saint Ouen L’AumôneParisFrance
  4. 4.Laboratoire d’Explorations FonctionnellesHôpital Necker-Enfants MaladesParisFrance
  5. 5.Department of Nephrology, Dialysis and HypertensionUniversity Hospital of LiègeLiègeBelgium

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