Clinical importance of vitamin E: a review

In 1922 Evans and Bishop described a fat soluble factor which was necessary for normal reproduction in the rat, and this factor subsequently became known as vitamin E. During the years that following the discovery and isolation of the vitamin, most of the work was concerned with the characterization of disorders found in experimental vitamin E deficient animals. It soon became apparent that vitamin E deficiency produces a wide variety of pathological conditions which differ not only amongst the various animal species but sometimes even within the same species (Wasserman & Taylor, 1972). The lesion, however, which predominates in most species is that of a chronic necrotising myopathy or dystrophy (Machlin, 1980). Even though vitamin E deficiency syndromes had been produced experimentally in animals, the role of the vitamin in human nutrition remained much disputed for a long time and little understood. Many ill-founded claims were made such as its ability to slow the ageing process or to increase virility and fertility, and even, as reported in the American press, to protect against the effects of atomic fallout. Not surprisingly this led some cynics to dub vitamin E as “E for Everything”. Nevertheless, some well documented evidence for a role in human nutrition was reported in the late 1950s. Oppenheimer (1956) and Blanc et al. (1958) showed that infants with cystic fibrosis had low serum vitamin E concentrations associated with widespread ceroid deposition in smooth muscle and focal necrosis of striated muscle. More recently evidence has accumulated indicating a pharmacological role for the vitamin in certain disorders affecting preterm infants (Aranda et al., 1986; Muller, 1987), and it has become clear that it has an important physiological role in maintaining normal neurological structure and function. It is accepted that it is an important biological antioxidant and is indeed the only significant fat soluble secondary antioxidant in mammalian tissues (Burton et al. 1983)