The function of UGT2A3 (UDP glucuronosyltransferase family 2 member A3, Ensembl gene identifier ENSG00000135220) is as follows. UDP-glucuronosyltransferase (UGT) that catalyzes phase II biotransformation reactions by conjugating glucuronic acid to lipophilic substrates, thereby increasing their water solubility and facilitating excretion. Catalyzes the glucuronidation of the bile acids hyodeoxycholic acid, deoxycholic acid, chenodeoxycholic acid, and ursodeoxycholic acid. {ECO:0000269|PubMed:18523138, ECO:0000269|PubMed:19858781}.