On-Demand - Vitamin D Measurements: Facts We May Not (Want to) Know
Over the past decade, 25-OH vitamin D has become one of the most common assays requested by physicians. The increase has been driven by claims that the vitamin has a role not only in calcium homeostasis but also in cardiovascular disease, stroke, cancer, autoimmune disease, and even fractures. Two major types of assays are used to measure vitamin D – immunoassay and mass spectrometry. Each of them has its strengths and weaknesses. Measurement is complicated by the existence of two forms of vitamin D (D2 and D3) as well as by the existence of epimers of both forms. Standardization has only recently been introduced, and proficiency testing, though available, reflects the poor state of the art. In this session, we will delve into the details of vitamin D measurement, aided by results from a recent study using the first FDA-reviewed mass spectrometry 25-OH vitamin D assay, and we will discuss ways of acknowledging, and dealing with, limitations of the various assays, so as to avoid misleading clinicians and adversely affect patient care.
Key Learning Objectives:
Accuracy of testing for total Vitamin D
Comparison of immunoassay and LC-MS for measuring Vitamin D
Advantages and limitations of different
Impact of proficiency testing
Gary L. Horowitz, MD
Tufts University School of Medicine
Can't make this event? Check out the events calendar to see other upcoming events that may be of interest.