calcitriol + oxidized [NADPH--hemoprotein reductase] + H2O + H(+) => alfacalcidol + reduced [NADPH--hemoprotein reductase] + O2
calcitriol + oxidized [nadph--hemoprotein reductase] + h2o + h(+) => alfacalcidol + reduced [nadph--hemoprotein reductase] + o2