[Vitamin D measurement: pre-analytical and analytical considerations]
Caroline Le Goff1, Jean-Claude Souberbielle2, Edgard Delvin3
1Service de chimie clinique, CHU de Liège, Belgique.
Annales De Biologie Clinique
|January 14, 2015
Summary
Standardizing serum 25-hydroxyvitamin D measurements is crucial due to varying results from different analytical methods. A collaborative program aims to harmonize automated, semi-automated, and mass spectrometry techniques for accurate vitamin D testing.
Area of Science:
- Clinical Chemistry
- Analytical Chemistry
- Endocrinology
Background:
- Increasing demand for serum 25-hydroxyvitamin D testing.
- Existing automated and semi-automated methods lack harmonization, leading to variable results.
- Emergence of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for improved specificity.
Purpose of the Study:
- To review challenges in current 25-hydroxyvitamin D measurement methods.
- To highlight the need for standardization across analytical platforms.
- To introduce a collaborative standardization program involving major health organizations.
Main Methods:
- Review of automated and semi-automated assays for 25-hydroxyvitamin D.
- Discussion of LC-MS/MS techniques for distinguishing vitamin D metabolites.
- Examination of sample preparation and analytical phase challenges.
- Consideration of mass spectrometry-related issues.
Main Results:
- Significant variability exists between different automated and semi-automated 25-hydroxyvitamin D assays.
- LC-MS/MS offers improved specificity but also requires harmonization.
- A multi-institutional standardization program has been developed to address these discrepancies.
Conclusions:
- Harmonization of 25-hydroxyvitamin D measurement methods is essential for clinical accuracy.
- Standardization efforts are underway involving key international institutions.
- Future work includes addressing clinical decision thresholds and measurements in alternative biological matrices.
Related Concept Videos
01:26Therapeutic Drug Monitoring: Drug Analysis Methods
327
Therapeutic Drug Monitoring (TDM) is a clinical practice that measures specific drug levels in a patient's blood or body tissues to tailor drug therapy effectively. This monitoring is critical for managing drugs with narrow therapeutic indices like digoxin and phenytoin, ensuring they are both safe and effective. For instance, monitoring theophylline levels in asthma patients involves precision and sensitivity to adjust doses according to individual responses to therapy, ensuring efficacy and...
327
01:23Role of Skin in Vitamin D Synthesis
9.1K
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...
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...
9.1K
01:20Measurement of Bioavailability: Pharmacodynamic Methods
983
Pharmacodynamic methods provide insights into a drug's effects on physiological processes over time and play a crucial role in understanding bioavailability and therapeutic efficacy. These methods can be broadly classified into acute pharmacological and therapeutic response approaches, each with distinct mechanisms and applications.The acute pharmacological response method directly correlates a drug's physiological effects, such as ECG or pupil diameter changes, to its time course in the body.
983
01:29Therapeutic Drug Monitoring: Affecting Factors
400
Therapeutic Drug Monitoring (TDM) is the clinical practice of measuring specific drug levels in a patient's blood or body tissues to manage and optimize therapy. TDM is crucial for drugs with narrow therapeutic windows, like warfarin and phenytoin, where incorrect doses can lead to treatment failure or severe side effects. This monitoring ensures the dosage administered is within a safe and effective range. The factors affecting therapeutic drug monitoring include:Patient-Specific Factors:a.
400
01:23Drug Concentrations: Measurements
1.7K
Drug concentration is the quantity of a drug present in a biological sample. Measuring drug amounts in biological samples allows the clinician to understand how a drug is absorbed, distributed, metabolized, and excreted. Samples can be obtained through invasive or non-invasive methods. Invasive techniques involve surgical or parenteral interventions to gather blood, cerebrospinal fluid, or tissue biopsy. Conversely, non-invasive approaches provide samples like urine, feces, and saliva.
Plasma...
Plasma...
1.7K