title: All-trans and 13-cis-retinoic acids are normal constituents of human blood formed from all-trans-retinyl palmitate.
abstract: All-trans and 13-cis-retinoic acids are normal constituents of human blood. Blood levels of both compounds increase upon oral ingestion of all-trans-retinyl palmitate, to a greater extent with higher amounts of ingested retinyl palmitate. These data suggest a mechanism whereby levels of dietary vitamin A could influence blood levels of the known cancer chemopreventive retinoic acids.
mesh_terms: D004224:Diterpenes; D006801:Humans; D009369:Neoplasms / Q000517:prevention & control*; D000084562:Retinyl Esters; D014212:Tretinoin / Q000097:blood*; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000378:metabolism / Q000627:therapeutic use*
chemical_list: D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate; D014212:Tretinoin