Vitamin A content (retinol and retinyl esters) in livers of different animals

In the present study, 90 animal livers of five different species (pig, cattle, calf, chicken, turkey) were examined for their vitamin A contents. The investigation of extracted vitamin A included all-trans retinol, retinyl palmitate, stearate, oleate and linoleate, expressed as retinol equivalents (RE). The separation of the various chemical forms was done using HPLC. The liver vitamin A contents ranged between 6.5 and 18.9 mg RE/100 g in pigs, from 1.1 to 6.7 mg RE/100 g in cattle and from 1.6 to 16.6 mg RE/100 g and 2.7 to 21.5 mg RE/100 g in chickens and turkeys, respectively. The livers of calves contained the smallest amount of vitamin A, with variation from 1.3 to 3.2 mg RE/100 g. Retinyl palmitate was the predominant form of vitamin A in the livers of investigated animals and contributed about 40% (avids) up to 75% (calf) of the total liver vitamin A contents. The results indicated that the lower levels of animal liver vitamin A, observed in our study, could be a result of small-structured agriculture in Austria. The variations of liver vitamin A concentrations among the species were a result of differences in race, age and the different feeding regimen.