Vitamin E is one of the body's most importantantioxidant nutrients. Antioxidants protect healthycells from oxidative and free radical damage. Freeradicals are unstable chemicals formed in the bodyduring metabolism and from exposure toenvironmental sources, such as air pollution andcigarette smoke. Free radicals are necessary forenergy metabolism and immune function, but whenan excessive number of free radicals are formed, theycan attack healthy cells, especially their membranelipids, proteins and nucleic acid. This, in turn, isthought to degrade the structure and function ofhealthy cellular components.
Vitamin E is an especially valuable antioxidant in thecell membranes, where it prevents oxidation ofunsaturated fatty acids by trapping free radicals. Thishelps stabilize and protect cell membranes, especiallyred blood cells and tissues sensitive to oxidation,such as the lungs, eyes and arteries. Vitamin E alsoprotects the liver and other tissues from the freeradicaldamage of toxicants, such as mercury, lead,ozone, nitrous oxide, carbon tetrachloride, benzene,cresol and various drugs. Related to its antioxidantproperties, vitamin E is important for normal immunefunction and many studies show that it prevents lipidperoxidation of blood lipoproteins, such as LDLcholesterol.
Vitamin E is the collective term for those eightcompounds that have varying levels of vitamin Ebiological activity. These eight fat solublecompounds include the alpha, beta, gamma, and deltaforms of tocopherol and tocotrienol. The mostbiologically active of this group is alpha tocopherol.Eight structural isomers of alpha tocopherol arepossible, but only the d-alpha tocopherol (RRR-alphatocopherol) occurs in nature. The other seven isomershave less nutritional activity and are present only insynthetic vitamin E (dl-alpha tocopherol). DouglasLaboratories' E-400 Dry Caps (Natural) containsonly the succinate esterified form of the natural dalphatocopherol isomer of vitamin E.
Intestinal absorption of vitamin E is associated withfat absorption. Some dietary fat must be present forefficient vitamin E absorption to occur. Studies showthat natural d-alpha tocopherol is more efficientlyabsorbed and has significantly higher bioavailabilitythan synthetic dl-alpha tocopherol. Once absorbed,vitamin E is transported into the circulatory systemvia chylomicrons, and then transferred to VLDL,LDL and HDL particles. Tissues slowly accumulatevitamin E from these plasma lipoproteins. Liver andadipose tissues have the highest concentrations, butmuscle also accounts for a large proportion ofvitamin E stores in the body.
Adults take 1 capsule daily with meals or as directed byphysician.