We established a method for simultaneous quantification of serum 1,25-dihydroxy vitamin D3 and 1,25-dihydroxy vitamin D2.
Sample preparation in this assay was much simpler. No immunoextraction or solid phase extraction procedure was needed.
The low limits of quantitation obtained were 10 pg/mL for both 1,25-dihydroxy vitamin D3 and 1,25-dihydroxy vitamin D2 without any derivation procedure.