What are Vitamin D2 and Vitamin D3?
Vitamin D2 is derived from fungal and plant sources, and is commonly found in supplements, such as multivitamins, in the U.S. Vitamin D2 may also be used in the pharmacological treatment of Vitamin D deficiency. Vitamin D3 is derived from animal sources and is made in the skin following exposure to sunlight. The LC/MS/MS technique is able to directly quantify Vitamin D2 and Vitamin D3. By comparison, immunoassay-based Vitamin D tests can only indirectly measure Vitamin D2 and Vitamin D3.
