Circulating concentrations of vitamins A and E in captive psittacine birds

Information about physiologic concentrations of vitamins A and E in captive psittacine birds would be useful in the diagnosis of potential vitamin deficiencies or toxicoses. To help provide this information, a retrospective study was done to assess circulating concentrations of vitamins A and E in captive Psittaciformes at 6 facilities representing 12 genera and 33 species. Plasma or serum samples collected from psittacine birds were analyzed for concentrations of α-tocopherol (n = 115) and retinol (n = 167). Mean retinol concentration (± standard deviation) in all birds was 0.471 ± 0.209 μg/ml, and mean α-tocopherol concentration was 13.05 ± 6.60 μg/ml. When compared by subfamily and genera, concentrations of both retinol and α-tocopherol differed significantly among groups. Post hoc testing demonstrated that differences in concentrations of retinol and, at the subfamily level, of α-tocopherol were attributable to low concentrations in Pesquet parrots (Psittrichas fulgidus). Differences at the genus level were mainly caused by high α-tocopherol concentrations in hyacinth macaws (Andorhynchus hyacinthinus). These results demonstrate that circulating concentrations of vitamins A and E in psittacine birds depend significantly on subfamily and genera.