Vitamin E
Vitamin E refers to molecules that exhibit the biological activity of alpha-
tocopherol. Alpha tocopherol is the most abundant form of vitamin E in the
body.
Serum Tocopherol
The tocopherols are carried in the blood by lipids. The ratio of tocopherol to
lipid provides a better estimate of vitamin-E status than tocopherol alone.
Adequate vitamin-E status is depicted by a level of approximately 0.8 mg total
tocopherol per gram of total lipids.
Erythrocyte Hemolysis Test
This is a functional test of the rate of hemolysis, based on the ability of
hydrogen peroxide to liberate hemoglobin from red cells. Hemolysis of over
10% is associated with vitamin-E deficiency, though it is not clear whether the
assay is indicative of alpha-tocopherol body stores or blood stores only.
Breath Pentane
Pentane and ethane are gases exhaled in the breath as a by-product of the
peroxidation of linolenic acid and linoleic acid. A negative
correlation has been found in children between plasma vitamin-E levels and
breath pentane. Breath pentane and ethane levels also increase in cases of
vitamin-C and beta-carotene deficiency.
