Abstract 10.1002/zoo.1024.abs After the loss of an African elephant (Loxodonta africana) in February 1989 at the Denver Zoological Gardens (DZG) with very low circulating serum α-tocopherol, a long-term study was initiated with three Asian elephants (Elephas maximus) to evaluate the effect of an oral micellized, water-soluble, natural source d-α-tocopherol supplement. Baseline α-tocopherol levels were evaluated and found to be approximately 3.75-fold less than those reported for semi-free-ranging Asian Nepalese work camp and free-ranging African elephants. The DZG elephants were then administered a liquid d-α-tocopherol (Emcelle®) at 2.2 IU/kg body weight orally once daily. Serum samples were obtained and analyzed at 1, 2, 8, and 12 months and then annually for 96 months. The oral vitamin E supplement significantly elevated serum levels above baseline and were found to be comparable with levels reported for semi–free-ranging and free-ranging elephants. Zoo Biol 20:245–250, 2001. © 2001 Wiley-Liss, Inc.