Enables alditol:NADP+ 1-oxidoreductase activity. Acts upstream of or within several processes, including epithelial cell maturation; metanephric collecting duct development; and renal water homeostasis. Predicted to be located in several cellular components, including Schmidt-Lanterman incisure; Schwann cell microvillus; and mast cell granule. Predicted to be active in cytosol. Is expressed in several structures, including alimentary system; genitourinary system; integumental system; nervous system; and sensory organ. Human ortholog(s) of this gene implicated in arteriosclerosis; cataract; diabetic neuropathy; diabetic retinopathy; and type 2 diabetes mellitus. Orthologous to human AKR1B1 (aldo-keto reductase family 1 member B). [provided by Alliance of Genome Resources, Apr 2022]