Both vitamin E and selenium play a role in metabolism and have anti-oxidant properties.
True: There is an interrelationship between selenium and vitamin E. Both play a role in metabolism as well as being anti-oxidants. In some cases, one can substitute for the other such that a deficiency is delayed. There are some deficiency symptoms that respond only to the supplementation of either selenium or vitamin E.
To learn more about vitamin and mineral supplements read the December 2009 e-Tips article Vitamin and Mineral Supplements for Horses and watch the archived webcast Nutritional Supplements for Horses by Dr. Carey Williams.