Vitamin E was discovered in the first half of the last century and intensively researched since. New concepts of its biological significance have been developed, e. g. the role of vitamin E for immune responses; and evolution of analytical methods, e. g. the determination of single isomers of tocopherols, helped to gain more insight into its metabolism. Important differences between synthetic and natural source vitamin E in terms of its bio-availability were discovered in the past two decades.
The aim of this booklet is to address these differences, since they prove to be important under certain conditions. By presenting data on the utilization of different vitamin E entities and isomers in livestock animals but also in other animal species and humans, the authors give an overview on current knowledge of this subject.