Circulating levels of vitamin E in captive Asian elephants ( Elephas maximus )

Circulating levels of α‐tocopherol (vitamin E) were examined via high‐performance liquid chromatography in four female Asian elephants ( Elephas maximus ) at the New York Zoological Park between 1983 and 1987. Plasma vitamin E averaged 0.08 μg/ml in 1983, and was considered deficient. Over a four‐year period of dietary supplementation ranging from 0.7 to 3.7 IU vitamin E/kg body mass (approximately 50 to 250 IU/kg diet as fed), mean plasma α‐tocopherol increased to 0.6 μg/ml. Plasma and dietary vitamin E were found to be significantly correlated (p < 0.025) in these animals. Serum or plasma vitamin E measured in an additional 20 elephants from eight other zoological institutions in the United States and Canada averaged 0.5 μg/ml, but values were not significantly correlated (p > 0.05) with calculated dietary levels of the vitamin. To achieve the mean value for circulating α‐tocopherol in captive elephants (0.5 μg/ml), feed must provide at least 1.0, and more likely 2.0 to 2.5 IU vitamin E/kg body mass (approximately 130 to 167 IU/kg diet).