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Toward Clarity in Clinical Vitamin D Status Assessment: 25(OH)D Assay Standardization
Neil Binkley1, Graham D Carter2
1University of Wisconsin Osteoporosis Clinical Research Program, University of Wisconsin-Madison, 2870 University Avenue, Madison, WI 53705, USA.
Endocrinology and Metabolism Clinics of North America
|October 30, 2017
Summary
Assay variations in 25-hydroxyvitamin D (25(OH)D) hinder vitamin D guidelines. The Vitamin D Standardization Program aims to standardize results, but clinical variability persists, delaying consensus on vitamin D status definitions.
Area of Science:
- Clinical Chemistry
- Biochemistry
- Public Health
Background:
- Significant variability exists in 25-hydroxyvitamin D (25(OH)D) assays.
- This variation impedes the development of consistent clinical and public health guidelines for vitamin D status.
Purpose of the Study:
- To address the challenges posed by assay variability in 25(OH)D measurements.
- To highlight the role of the Vitamin D Standardization Program in improving measurement accuracy and consistency.
Main Methods:
- Development of reference measurement procedures.
- Creation of standard reference materials for assay standardization.
- Implementation of current, prospective, and retrospective standardization of 25(OH)D results.
Main Results:
- The Vitamin D Standardization Program has developed tools for standardizing 25(OH)D measurements.
- Despite standardization efforts, substantial variability in clinical laboratory measurements of 25(OH)D persists.
- Existing guidelines lack standardization, hindering consensus on vitamin D status definitions.
Conclusions:
- Standardization of 25(OH)D assays is crucial for reliable vitamin D status assessment.
- Continued clinical laboratory variability challenges the establishment of evidence-based consensus on vitamin D deficiency, inadequacy, sufficiency, and excess.
- A pragmatic clinical approach is recommended until consensus is achieved.
