1 Alpha-25,26-trihydroxyvitamin D3: an in vivo and in vitro metabolite of vitamin D3

Biochemistry. 1981 Oct 13;20(21):6230-5. doi: 10.1021/bi00524a050.


A new metabolite of vitamin D3 has been isolated from the plasma of vitamin D3 treated cows and has been generated from 25(S),26-dihydroxyvitamin D3 with homogenates of vitamin D deficient chick kidney. This metabolite has been identified as 1,25,26-trihydroxyvitamin D3 by comigration with synthetic 1,25(S),26-trihydroxyvitamin D3 in four chromatographic systems, ultraviolet spectroscopy, mass spectrometry, and high-pressure liquid chromatography and mass spectrometry of derivatives. 1,25(S),26-Trihydroxyvitamin D3 is one-tenth as effective as 1,25-dihydroxyvitamin D3 in binding to the chick intestinal cytosol 1,25-dihydroxyvitamin D receptor. Either 25(S),26-dihydroxyvitamin D3 or 1,25-dihydroxyvitamin D3 can serve as precursor for in vitro production of 1,25,26-trihydroxyvitamin D3 by chick kidney tissue.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Biological Assay
  • Cattle
  • Chickens
  • Cholecalciferol / metabolism*
  • Chromatography, High Pressure Liquid
  • Female
  • Hydroxycholecalciferols / biosynthesis*
  • Hydroxycholecalciferols / blood
  • Mass Spectrometry
  • Receptors, Calcitriol
  • Receptors, Steroid / metabolism
  • Spectrophotometry, Ultraviolet


  • Hydroxycholecalciferols
  • Receptors, Calcitriol
  • Receptors, Steroid
  • Cholecalciferol
  • 1,25,26-trihydroxyvitamin D3