Tocopherol is a fat-soluble vitamin with antioxidant properties; it protects cell membranes from oxidation and destruction. Vitamin E is found in a variety of foods, including oils, meat, eggs, and leafy vegetables. Serum vitamin E levels are strongly influenced by concentration of serum lipids and do not accurately reflect tissue vitamin levels. Effective vitamin E levels are calculated as the ratio of serum alpha-tocopherol per gram total lipids. Vitamin E reserves in lung tissue provide a barrier against air pollution and protect red blood cell membrane integrity from oxidation. Oxidation of fatty acids in red blood cell membranes can result in irreversible membrane damage and hemolysis. Studies are in progress to confirm the suspicion that oxidation also contributes to the formation of cataracts and macular degeneration of the retina. Because vitamin E is found in a wide variety of foods, a deficiency secondary to inadequate dietary intake is rare.
Increased: obstructive liver disease, hyperlipidemia, vitamin E intoxication
Decreased: abetalipoproteinemia, hemolytic anemia, malabsorption disorders, such as biliary atresia, cirrhosis, CF, chronic pancreatitis,
pancreatic carcinoma, and chronic cholestasis