Jenny F.S. Basran, BSc, MD, and David B. Hogan MD, FACP, FRCPC
Division of Geriatric Medicine, University of Calgary, Calgary, AB.
Introduction
Recently, there has been growing interest in the use of vitamins for the treatment of various health conditions. One study has estimated that 35-54% of older Canadians take some form of vitamin or mineral supplement.1 Oxidative stress has been theorized to be an important contributor to select conditions, particularly those involving the cardiovascular and central nervous systems. Vitamin E is the only fat-soluble, chain-breaking antioxidant found in biological membranes4 and, therefore, has been investigated for its use in the treatment of ischemic cardiovascular disease in recent landmark studies such as the Heart Outcome Evaluation Study (HOPE)2 and Heart Protection Study (HPS).3
How Does Vitamin E Work?
Vitamin E is a generic term for chemical derivatives of tocopherol and tocotrienol.5 There are eight naturally occurring forms, but only a-tocopherol is found in human plasma, has the highest bioactivity and is the form used for medicinal purposes. a-tocopherol is found naturally in vegetable oils, almonds, sunflower seeds, walnuts, sweet potato, liver, wheat germ and egg yolk.6 Synthetic forms are available as vitamin capsules and in fortified foods.
