Metabolism of l-Alpha-Tocopherol by the Vitamin E-Deficient Rabbit.

Abstract
Summary Nutritional muscular dystrophy in the rabbit can be cured by l-alpha-tocopheryl acetate administered either orally or intravenously. Based on duration of survival after a single 50 mg oral dose the average estimated daily requirement was 2.0 mg per kg of body weight for 3 rabbits that received d-alpha-tocopheryl acetate and 9.5 for 2 rabbits that received l-alpha-tocopheryl acetate. After intravenous treatment with the same dose of these compounds, using 2 rabbits in each group, the estimated requirements were 1.2 and 8.0 for the d- and l-epimers, respectively. Liver and serum concentrations of tocopherol decreased more rapidly after treatment with l-alpha-tocopheryl acetate than after treatment with the same amounts of d-alpha-tocopheryl acetate. These observations suggest that the biological inferiority of l-alpha-tocopherol is due, at least in part, to a faster rate of loss from the body.