Additional Resources

Learn more about bone metabolism and vitamin D testing.

Variability in results of hormone assays such as vitamin D and testosterone can adversely affect patient care, and variability in results between methods has made it challenging to assign cutoff values for diagnosis and to develop public health guidelines. The CDC Vitamin D Standardization Program (VDSP) developed reference methods and materials for standardization and harmonization of vitamin D assays so that results could be compared across manufacturers, laboratories, and time. Similar to vitamin D, inconsistencies in total testosterone results between assays have led to the CDC Hormone Standardization Program (CDC HoST) Certified Total Testosterone Procedures, and the quality of both vitamin D and total testosterone assays results are maintained through ongoing quarterly challenges.

Use of Siemens Healthineers ADVIA Centaur®, Atellica® IM, and Dimension® EXL™ Vitamin D Total assays and ADVIA Centaur Testosterone II and Dimension EXL Total Testosterone assays that are standardized and CDC-certified may help ensure harmonization, accurate results, and optimal patient care.

The incidence of vitamin D intoxication has doubled from 2017 to 2018, which may be due to the prescription of vitamin D megadose therapy in therapeutic protocols as a treatment for autoimmune and other disorders. It is important for clinicians to understand the risks of intoxication associated with megadose therapy of vitamin D.

Dr. Cleide de Oliveira Weingrill Sabino, from DASA in Brazil, discusses her research on vitamin D doses and the associated rise in calcium levels, which can lead to hypercalcemia.