The Reference Method

This version of the course is no longer available.
Need multiple seats for your university or lab? Get a quote
The page below is a sample from the LabCE course . Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

Learn more about (online CE course)
The Reference Method

The reference method for vitamin D analysis has been liquid chromatography - mass spectrophotometry (LC-MS/MS), which can measure vitamin D2, vitamin D3, and the D3 epimer (one of a pair of stereoisomers) separately and, through a calculation, the total vitamin D is reported. This method was chosen by the Nutritional Laboratory at the Centers for Disease Control and Prevention (CDC) and the National Laboratory in the United Kingdom for analysis of vitamin D for health and nutrition surveys, partly due to its ability to distinguish the various forms of vitamin D in plasma that may be found in people of all ages. The problem with these methods is that they are time and labor intensive and technically difficult to perform.