Oxidoreductase with a preference for NAD. Oxidizes all-trans-retinol, 9-cis-retinol, 11-cis-retinol and 13-cis-retinol to the corresponding aldehydes (PubMed:7499345). Has higher activity towards CRBP-bound retinol than with free retinol (By similarity). Oxidizes 3-alpha-hydroxysteroids. Oxidizes androstanediol and androsterone to dihydrotestosterone and androstanedione. Can also catalyze the reverse reaction (By similarity). all-trans-retinol--[retinol-binding protein] + NAD(+) = all-trans-retinal--[retinol-binding protein] + H(+) + NADH all-trans-retinol + NAD(+) = all-trans-retinal + H(+) + NADH 13-cis-retinol + NAD(+) = 13-cis-retinal + H(+) + NADH 11-cis-retinol + NAD(+) = 11-cis-retinal + H(+) + NADH 9-cis-retinol + NAD(+) = 9-cis-retinal + H(+) + NADH 5alpha-androstane-3alpha,17beta-diol + NAD(+) = 17beta-hydroxy-5alpha-androstan-3-one + H(+) + NADH 3alpha-hydroxy-5alpha-androstan-17-one + NAD(+) = 5alpha-androstan-3,17-dione + H(+) + NADH Cofactor metabolism; retinol metabolism. Homodimer. Liver > kidney > brain > lung > testis. The C-terminal region plays a crucial role in controlling the activity of RDH16 and its required for endoplasmic reticulum (ER) retention. Not N-glycosylated. Belongs to the short-chain dehydrogenases/reductases (SDR) family. Membrane topology is controversial (PubMed:11601977). Membrane topology structure with endoplasmic reticulum lumen orientation of the catalytic domains while the C-terminus is in the cytosol have been suggested by one study (By similarity). Others investigators have argued for a reverse orientation, with a membrane-embedded N-terminal domain but no C-terminal transmembrane segment, and a cytosolic orientation of the catalytic domain (PubMed:11601977). These contracductoty results are probably because of differences in the assay systems.