(1S)-1-hydroxy-23-oxo-24,25,26,27-tetranorcalciol + 2 oxidized [adrenodoxin] + 2 H2O => (1S)-1,23-dihydroxy-24,25,26,27-tetranorcalciol + 2 reduced [adrenodoxin] + O2 + 2 H(+)
(1s)-1-hydroxy-23-oxo-24,25,26,27-tetranorcalciol + 2 oxidized [adrenodoxin] + 2 h2o => (1s)-1,23-dihydroxy-24,25,26,27-tetranorcalciol + 2 reduced [adrenodoxin] + o2 + 2 h(+)