Generally it is not necessary to differentiate the two forms. The total 25OH Vitamin D is the important measurement and is the best indicator of Vitamin D status. A recent report suggested that reporting separate values for 25OH Vitamin D2 and 25OH Vitamin D3 confused some clinicians. However, if a clinical trial involves the use of Vitamin D2 as a supplement, the scientist may wish to have each form identified to monitor their contribution to the total 25OH Vitamin D.
