(25R)-3alpha,7alpha-dihydroxy-5beta-cholestan-26-oate + reduced [NADPH--hemoprotein reductase] + O2 => (25R)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-oate + oxidized [NADPH--hemoprotein reductase] + H2O + H(+)
(25r)-3alpha,7alpha-dihydroxy-5beta-cholestan-26-oate + reduced [nadph--hemoprotein reductase] + o2 => (25r)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-oate + oxidized [nadph--hemoprotein reductase] + h2o + h(+)