A comparison of oral and topical vitamin A supplementation in African foam-nesting frogs (Chiromantis xerampelina).

Vitamin A is essential for a variety of functions, including cellular differentiation, morphogenesis, growth, vision, immune response, and reproduction. A captive population of African foam-nesting frogs (Chiromantis xerampelina) with a known history of vitamin A deficiency had higher than expected incidence of sudden death, bacterial osteomyelitis, and stunted growth. Due to the high prevalence and untreatable nature of the diseases in the population, euthanasia of the population was recommended. Before euthanasia, the population was entered into a study to compare oral dietary supplementation of vitamin A to topical treatment with water-miscible vitamin A palmitate (AQUASOL A Parenteral, Mayne Pharma Inc., Paramus, New Jersey 07652, U.S.A.). Eighty-four frogs, weighing 2-7 g, were divided into a control and three treatment groups of 21 frogs per group, with normalized weight distribution. The control group received standard daily nutrition of crickets dusted with a supplement containing 342,000 international units (IU) vitamin A/kg. The treatment groups consisted of oral supplementation with crickets dusted with a fortified supplement containing 822,510 IU vitamin A/kg; topical vitamin A palmitate 50 IU every other day; and topical vitamin A palmitate 50 IU once a week. After 30 days, all frogs were euthanized, and 12 frogs from each group were analyzed for whole-body vitamin A levels. The control and treatment groups 1, 2, and 3 had average whole-body vitamin A levels of 1371.4 IU/kg (SE 284.4), 908.7 IU/kg (SE 186.5), 6385.9 IU/kg (SE 675.9), and 3521.8 IU/kg (SE 575.1), respectively. These results suggest that oral supplementation using a product high in vitamin A may be ineffective at raising whole-body vitamin A levels above those achieved with standard nutrition. Topical administration of vitamin A on an every other day and once a week dosing schedule achieved levels 4.5- and 2.5-fold higher than standard nutrition, respectively.