Catalyzes the stereospecific NADPH-dependent reduction of the C4-C5 double bond of bile acid intermediates and steroid hormones carrying a delta(4)-3-one structure to yield an A/B cis-ring junction. This cis-configuration is crucial for bile acid biosynthesis and plays important roles in steroid metabolism. Capable of reducing a broad range of delta-(4)-3-ketosteroids from C18 (such as, 17beta-hydroxyestr-4-en-3-one) to C27 (such as, 7alpha-hydroxycholest-4-en-3-one). 5beta-cholestan-3-one + NADP(+) = cholest-4-en-3-one + H(+) + NADPH 4,5beta-dihydrocortisone + NADP(+) = cortisone + H(+) + NADPH cortisol + H(+) + NADPH = 5beta-dihydrocortisol + NADP(+) corticosterone + H(+) + NADPH = 5beta-dihydrocorticosterone + NADP(+) 7alpha,12alpha-dihydroxycholest-4-en-3-one + H(+) + NADPH = 7alpha,12alpha-dihydroxy-5beta-cholestan-3-one + NADP(+) 7alpha-hydroxycholest-4-en-3-one + H(+) + NADPH = 7alpha-hydroxy-5beta-cholestan-3-one + NADP(+) epitestosterone + H(+) + NADPH = 5beta-dihydroepitestosterone + NADP(+) androst-4-ene-3,17-dione + H(+) + NADPH = 5beta-androstane-3,17-dione + NADP(+) H(+) + NADPH + progesterone = 5beta-pregnan-3,20-dione + NADP(+) 21-hydroxyprogesterone + H(+) + NADPH = 5beta-dihydrodeoxycorticosterone + NADP(+) aldosterone + H(+) + NADPH = 5beta-dihydroaldosterone + NADP(+) 17beta-hydroxyandrosta-1,4-dien-3-one + H(+) + NADPH = 17beta-hydroxy-5beta-androst-1-en-3-one + NADP(+) 17beta-hydroxyestr-4-en-3-one + H(+) + NADPH = 17beta-hydroxy-5beta-estran-3-one + NADP(+) 5beta-dihydrotestosterone + NADP(+) = H(+) + NADPH + testosterone androst-4-ene-3,11,17-trione + H(+) + NADPH = 17beta-hydroxyandrost-4-ene-3,11-dione + NADP(+) Subject to inhibition by high substrate concentrations. Inhibited by testosterone concentrations above 10 uM (PubMed:18407998). Inhibited by the primary and secondary bile acids chenodeoxycholic acid and ursodeoxycholic acid (PubMed:21255593). kcat is 2.7 min(-1) with 17beta-hydroxyestr-4-en-3-one as substrate. kcat is 6.0 min(-1) with androst-4-ene-3,17-dione as substrate. kcat is 8.4 min(-1) with testosterone as substrate. kcat is 6.0 min(-1) with epitestosterone as substrate. kcat is 3.2 min(-1) with 17beta-hydroxyandrosta-1,4-dien-3-one as substrate. kcat is 9.0 min(-1) with aldosterone as substrate. kcat is 1.9 min(-1) with corticosterone as substrate. kcat is 2.7 min(-1) with cortisol as substrate. kcat is 11.2 min(-1) with cortisone as substrate. kcat is 2.0 min(-1) with 7alpha-hydroxycholest-4-en-3-one as substrate. kcat is 0.6 min(-1) with cholest-4-en-3-one as substrate. Optimum pH is 6. Highly expressed in liver. Expressed in testis and weakly in colon. The disease is caused by variants affecting the gene represented in this entry. Belongs to the aldo/keto reductase family.