Skip to main content

Accuracy of 25-Hydroxyvitamin D Assays: Confronting the Issues

Buy Article:

$55.00 plus tax (Refund Policy)

Measurement of 25-hydroxyvitamin D (25-OHD) is widely used for assessing vitamin D status. There has been a dramatic increase in 25-OHD requests over recent years prompting many laboratories to consider the use of automated immunoassays. To achieve higher throughput, these methods have abandoned the traditional solvent extraction of samples and are therefore more prone to non-specific interference. The Vitamin D External Quality Assessment Scheme (DEQAS) has revealed method-related differences in 25-OHD results, raising concerns about the comparability and accuracy of different assays. This paper highlights some of the pre-analytical, analytical and post-analytical issues which may influence the accuracy of 25-OHD assays and interpretation of results. Recent attention has focused on reconciling the relatively high results given by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to those of the DiaSorin radioimmunoassay (RIA) on which clinical decision points have previously been based. Data is presented on 20 DEQAS samples which were analysed by an LC-MS/MS assay developed as a candidate reference measurement procedure by the US National Institute of Standards and Technology (NIST). The NIST results were on average 11.2% lower than those given by routine LC-MS/MS methods. If confirmed, these results suggest that most routine LC-MS/MS assays are perhaps overestimating 25-OHD by failing to resolve a molecule having the same mass as 25-OHD3 and a similar fragmentation pattern. All 25-OHD assays should be monitored by a proficiency testing scheme and the results made available to clinicians and editors of scientific journals.





No References
No Citations
No Supplementary Data
No Data/Media
No Metrics

Keywords: 25-Hydroxyvitamin D; 25-OHD3; 7-dehydrocholesterol (provitamin D); D binding protein; DEQAS; DiaSorin; ESA; GC-MS; NIST; RMP; UV spectrophotometry; Vitamin D External Quality Assessment Scheme; accuracy; competitive protein-binding (CPB) assay; enzyme immunoassay (EIA); liquid chromatography; liquid chromatography-tandem mass spectrometry (LC-MS/MS); mass spectrometry; methods; proficiency-testing scheme; radioimmunoassay

Document Type: Research Article

Publication date: 2011-01-01

More about this publication?
  • Current Drug Targets aims to cover the latest and most outstanding developments on the medicinal chemistry and pharmacology of molecular drug targets e.g. disease specific proteins, receptors, enzymes, genes. Each issue of the journal will be devoted to a single timely topic, with series of in-depth reviews, written by leaders in the field, covering a range of current topics on drug targets. These issues will be organized and led by a guest editor who is a recognized expert in the overall topic. As the discovery, identification, characterisation and validation of novel human drug targets for drug discovery continues to grow; this journal will be essential reading for all pharmaceutical scientists involved in drug discovery and development.
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more