23, 25, 26-trihydroxycholecalciferol. A 25-hydroxycholecalciferol-26,23-lactone precursor.

(23S)-23,25-Dihydroxycholecalciferol was converted into at least five metabolites in kidney homogenates prepared from 1,25-dihydroxycholecalciferol-treated chickens. One of these has been positively identified as 23,25,26-trihydroxycholecalciferol by u.v.-absorbance analysis, mass spectrometry and chemical formation of derivatives. 23,25,26-Trihydroxycholecaciferol produces 25-hydroxycholecalciferol-26,23-lactone when incubated in chick kidney homogenates.