A cytochrome P450 monooxygenase that may play a major role in intestinal retinoid metabolism. Catalyzes the oxidative transformation of all-trans retinal and 9-cis-retinal to the corresponding active forms all-trans and 9-cis retinoic acids (PubMed:9606960). Catalyzes the hydroxylation of carbon-hydrogen bonds. Hydroxylates arachidonic acid predominantly at the omega-1 position (PubMed:9143331). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (CPR; NADPH--hemoprotein reductase) (PubMed:9143331, PubMed:9606960). an organic molecule + O2 + reduced [NADPH--hemoprotein reductase] = an alcohol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = 19-hydroxy-(5Z,8Z,11Z,14Z)-eicosatetraenoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] all-trans-retinal + O2 + reduced [NADPH--hemoprotein reductase] = all-trans-retinoate + 2 H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 9-cis-retinal + O2 + reduced [NADPH--hemoprotein reductase] = 9-cis-retinoate + 2 H(+) + H2O + oxidized [NADPH--hemoprotein reductase] Lipid metabolism; arachidonate metabolism. Cofactor metabolism; retinol metabolism. Expressed in small intestinal enterocytes (at protein level) (PubMed:9143331). In the intestinal crypt, expressed at higher levels in the mature villous cells than in undifferentiated crypt cells (at protein level) (PubMed:9143331, PubMed:9606960). Expressed in liver, kidney, lung, and olfactory mucosa (at protein level) (PubMed:9143331). Belongs to the cytochrome P450 family.