Calcium Homeostasis and Vitamin D: What Are Vitamin D Tests Actually Measuring?


The lecture will review basic calcium homeostasis, with an emphasis on how Vitamin D is involved in the regulation. The health benefits and risks of Vitamin D supplementation will be discussed, including current recommendations. A summary of strengths and weaknesses of the currently available test methods, from immunoassay to mass spectrometry, will be discussed. In addition, the use of certified reference materials and proficiency testing materials and their contribution to method harmonization will be outlined.

Originally presented on October 30, 2014, in Salt Lake City, Utah.

Lecture Presenter

Joely A. Straseski, PhD, MS, MT(ASCP), DABCC

Joely A. Straseski, PhD, MS, MT(ASCP), DABCC

Medical Director, Endocrinology Laboratory
ARUP Laboratories
Assistant Professor of Pathology
University of Utah School of Medicine

Dr. Straseski is a medical director of endocrinology at ARUP and an assistant professor of pathology at the University of Utah School of Medicine. She received her PhD in pathology and laboratory medicine and a master of science in bacteriology from the University of Wisconsin-Madison, where she also served as a postdoctoral associate in the Department of Pathology. Dr. Straseski completed a postdoctoral fellowship in clinical chemistry at the Johns Hopkins Medical Institutions in Baltimore, Maryland. She has previously been awarded the Past-Presidents’ Scholarship by the American Association for Clinical Chemistry, as well as a Distinguished Abstract Award from the National Academy of Clinical Biochemistry. Dr. Straseski is board certified in clinical chemistry by the American Board of Clinical Chemistry


After this presentation, participants will be able to:

  • Review Vitamin D actions and the implications of deficiency.
  • Compare and contrast current methods for measuring 25-hydroxyvitamin D.
  • Examine the current state of method harmonization and future efforts in this area.

Sponsored by:

University of Utah School of Medicine, Department of Pathology, and ARUP Laboratories