Pitfalls in the Implementation of 25OH Vitamin D Assays by LC-MS
Tue 3:30 PM - Track 1: Vitamin D
Darryl Erik Palmer-Toy
Kaiser Permanente
Darryl Palmer-Toy, Qibo Jiang, Gene Usher

Kaiser Permanente, Southern California Regional Reference Laboratories
LC-MS is an attractive option for the accurate, sensitive, and specific measurement of 25-hydroxy vitamins D2 and D3 in human serum. However, the successful development and implementation of such a clinical assay presents many pitfalls to the unwary, as we can relate from personal experience. In this lecture, I will discuss nine specific questions:

  • Sample collection
    • Does phlebotomy tube affect sample stability?

  • Preanalytic processing
    • How to maximize recovery?

  • Can we reduce labor and imprecision through automation?

  • Assay standardization
    • To what reference should we standardize?

  • Chromatography
    • Which interfering substances must be separated?

  • Mass spectrometery
    • Which masses should be monitored?

  • Personnel
    • Can your average CLS successfully perform this test?