Related Experiment Videos
Determining vitamin D status: a comparison between commercially available assays
Greta Snellman1, Håkan Melhus, Rolf Gedeborg
1Section of Orthopaedics, Department of Surgical Sciences, Uppsala University, [corrected] Uppsala, Sweden. greta.snellman@surgsci.uu.se
Plos One
|July 21, 2010
Summary
Vitamin D testing assays show significant differences in results, impacting insufficiency diagnoses. High-pressure liquid chromatography-mass spectrometry (HPLC-MS) proved most accurate for 25-hydroxyvitamin D levels.
Area of Science:
- Clinical Chemistry
- Biochemistry
- Endocrinology
Background:
- Vitamin D is crucial for bone health and influences non-bone diseases.
- Accurate measurement of 25-hydroxyvitamin D is vital for defining vitamin D status.
- Existing assays for 25-hydroxyvitamin D lack comparability, necessitating performance evaluation.
Purpose of the Study:
- To investigate the precision, accuracy, and clinical implications of performance differences among three common 25-hydroxyvitamin D assays.
- To compare results from high-pressure liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (HPLC-APCI-MS), radioimmunoassay (RIA), and chemiluminescent immunoassay (CLIA).
Main Methods:
- Serum 25-hydroxyvitamin D levels were measured in 204 twins using HPLC-APCI-MS, RIA, and CLIA.
- Assay performance was assessed by comparing inter-assay agreement and accuracy via within-twin pair correlations.
- Regression analyses examined variance across different 25-hydroxyvitamin D levels.
Main Results:
- Significant inter-assay disagreement was observed, with mean levels highest for HPLC-APCI-MS (85 nmol/L), intermediate for RIA (70 nmol/L), and lowest for CLIA (60 nmol/L).
- Vitamin D insufficiency (50 nmol/L cut-off) prevalence varied: 8% (HPLC-APCI-MS), 22% (RIA), and 43% (CLIA).
- HPLC-APCI-MS showed the strongest within-twin pair correlation (r=0.7), indicating higher accuracy, compared to RIA (r=0.5) and CLIA (r=0.4).
Conclusions:
- Substantial performance differences exist among 25-hydroxyvitamin D assays.
- HPLC-APCI-MS was identified as the most valid method for measuring 25-hydroxyvitamin D.
- Calibration and standardization of 25-hydroxyvitamin D assays remain a complex challenge.
Related Concept Videos
01:23Role of Skin in Vitamin D Synthesis
The skin plays a crucial role in the synthesis of vitamin D, a vital nutrient for various physiological processes in the body. Vitamin D is unique because it can be synthesized in the skin through a series of chemical reactions triggered by exposure to ultraviolet B (UVB) radiation from sunlight.
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
01:24Automated Microbial Diagnostics
Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe...