Vitamin E: the enigmatic one!

Vitamin E was first identified more than 90 years ago by Evans and Bishop as an essential dietary factor that is required by rats to maintain normal reproduction (1). Unlike the other three fat-soluble vitamins that have very specific molecular targets and actions, vitamin E lacks specific pathways or specific molecular targets that account for its requirement from the diet. Considerable research had been focused on identifying specific molecular targets and actions for vitamin E (2). For instance, as it became clear that vitamins A and D act through cognate nuclear hormone receptors to regulate vitamin-responsive gene expression, investigators sought, without success, to identify similar activities for vitamin E.