VITAMIN E (Tocopherol)

General - oil-soluble; anti-sterility factor; oil-soluble antioxidant;

• Vitamin E is the official designation for alpha tocopherol, a fat-soluble nutrient found in the diet in varying amounts. Until recently it was thought that alpha tocopherol was the most active tocopherol and as such only official vitamin E activity (IU) is given to alpha tocopherol.
• The term vitamin E is now used to refer to all tocol and trienal derivatives. The tocols are alpha, beta, delta and gamma tocopherol, and the trienals are alpha, beta, delta and gamma tocotrienol.
• Gamma tocopherol, a potent antioxidant of ozone and nitric oxide is now shown to be as important as alpha tocopherol. The National Academy of Sciences now suggests that vitamin E formulas contain both tocopherols and that gamma tocopherol be the predominant one.
• Tocotrienols have potent anti-oxidant activity, but their turnover rate in human tissues is rapid and therefore unlikely to provide more than transitory effect, and little benefit as a nutritional supplement.
• Vitamin E esters such as alpha tocopheryl acetate and alpha tocopheryl succinate are not antioxidants in that form and must first be enzymatically de-esterified in the gut to the biologically active tocopherols before they function in the human system. This is an inefficient process and and more than 50% of the ester may not be converted.
• History: “anti-sterility factor” described in 1911; isolated in 1936; identified in 1938; recognized as essential for humans in 1968; deficiency syndrome described in 1977;

Nutrition

• Sources: wheat germ, wheat germ oil, whole grain, unrefined vegetable oil, nuts, seeds, eggs, whole grains, green leafy vegetables;
• Supplements: “dry” E acetate or succinate, d-alpha tocopherol, gamma/alpha tocopherols, multivitamin, multi-mineral-vitamin formulations;
• Absorption from small intestine, along with fats; 40 to 60% is absorbed into lymph (in chylomicrons); remainder is discarded in feces;
• Improved by: edible fats & oils; by taking with a meal; vitamin C prevents its oxidation; vitamin A aids in transport; manganese & selenium;
• Antagonized by: salts & sugar/acid chelates of iron & copper (oxides, carbonates, gluconates, succinates, acetates, etc.); oxygen; rancid food oils; processed foods; mineral oil; oral contraceptives; freezing; oxidizing agents, ozone & nitrogen oxides;
• Stability: destroyed by light & oxygen; heat-stable in boiling, but destroyed during frying & deep frying; some lost in frozen storage; storage at room temperature may decrease vitamin E content of foods by up to 50% within 2 weeks; encapsulation protects vitamin E against destruction;
• Storage: largely in adipose tissue, liver & muscle; high concentrations also found in blood platelets, pituitary, adrenals, testes, ovaries;
• Metabolism: plasma levels drop to half within a few days when vitamin E is withdrawn from foods; frank deficiency may take several months to develop; Functions of vitamin E
• Chief activity in all cells & tissues is anti-oxidant; prevents oxygen from destroying many other compounds, including vitamin A & C, unsaturated fatty acids & membranes (phospholipids); (Note: oxygen is vital to cell respiration, but will damage cells if antioxidants fail to keep it under control);
• Vital to digestion & metabolism of unsaturated fats; Protects cells from damaging pollutants, peroxides & free radicals formed from organic molecules during normal metabolic processes; protects lungs against air pollution;
• Protects membrane integrity of cells in circulatory, digestive, respiratory, excretory & nervous systems; protects vitamin A against destruction by free radicals;
• Stimulates development & tone of skeletal, heart & digestive tract muscles;
• Retards aging processes of cells; prolongs life of red blood cells;
• Vitamin E & C reduces the formation of nitrosamines (carcinogen) in bacon;
• Gamma tocopherol plays a critical role in the defence against cancer and cardiovascular disease by inhibiting the process of inflammation more effectively that alpha tocopherol.

Quantities

• Measurement: 1 mg d-alpha tocopherol = 1.49 International Units (IU);
  1 mg dl-alpha tocopheryl acetate = 1 IU = 1 tocopherol equivalent (TE);
• Optimum: (SONA) average ranges from 70 to 800 IU; increases with amount of unsaturated fatty acids in diet; high intake of unsaturated fats increases the rate of oxidative destruction of vitamin E, which sacrifices itself to spare fat & membranes;
• Individual optimum must be determined for each individual;
• Minimum: (DRI) average is set at 15 mg (22 IU);
• Less than RDA: estimated at 20 - 40% of population, due to reliance on processed foods;
• Deficiency from: insufficient intake; poor absorption (inflammatory bowel disease, cystic fibrosis, premature birth); lack of fats in diet; mineral oil; iron & copper salts; injury & tissue destruction, which rapidly use up body’s supplies; rancid oils; increased requirement (premature infants, pregnant & lactating women); - intake of vitamin E from foods has fallen 95% since 1900, due to removal during food processing; deficiency is widespread in un-supplemented diets;
• Symptoms include: formation of peroxides, dienes & free radicals within cells, formed by oxidation of membrane fats & of soluble factors in cell cytoplasm; rupture of cell membranes; destruction or irreparable damage to nearby cells by substances spilling from ruptured cells; damage transmitted to future generations of cells; shortened red blood cell life; production of age pigment spots (ceroid pigments; lipofuscin);
• First clinical signs of deficiency: ruptured red blood cells (haemolysis), followed by abnormal deposits of fat in heart & muscles, shrinkage of connective tissues &/or muscle degeneration;
• Prolonged deficiency impairs absorption of fat & fat soluble vitamins, can lead to degeneration of the testes in men; nephritis from kidney tubule blockage by dead cells; blockage of bile duct; chronic pancreatitis; chronic gastrointestinal disorders; thrombotic conditions of the cardiovascular system; infertility in men & women; progressive neuro-muscular disease in children & adults (nutritional muscular dystrophy); formation of age pigments (lipofuscin); vitamin E deficiency anaemia from oxidative destruction of red blood cells; premature infants especially at risk — haemolytic anaemia, intraventricular haemorrhage, retrolenticular fibroplasias that can lead to blindness;
• Toxicity: virtually impossible to overdose on vitamin E; 200 times RDA (up to 3,000 IU/day) is safe for most people;
• Very high intake may increase bleeding tendency in patients on anti-coagulant drugs;
• Extreme supplementation may increase blood pressure in some people; hypertensive individuals start with low quantities & increase by 100 IU/week;
• Persons with rheumatic heart conditions may have to limit vitamin E intake to 150 IU/day; supervision by nutritionally competent health care professional is recommended;

Therapy with vitamin E

• 100-1,600 IU/day is usual therapeutic range; up to 3,200 IU/day used in menopause;
• Corrects the foregoing deficiency conditions if degeneration of the tissue has not progressed to irreparable damage;
• Reverses nutritional muscular dystrophy;
• Protects brain & nerves, muscles, heart & arteries, glands & reproductive organs from oxidative damage throughout life;
• Russian athletes use up to 150 IU/2-hour training to spare oxygen & promote endurance;
• Improves varicose veins, inflamed veins with blood clots (thrombophlebitis) & intermittent claudication; soothes dry itchy skin; regulates menstrual flow; prevents & alleviates some migraine headaches; prevents miscarriages;
• Protects lungs from damage due to smog; retards aging; preventive against cancer & heart disease, as well as general degeneration;
• Up to 100 IU/day used in premature infants, to protect cell membranes in brain, nerves, heart & muscles from oxidative destruction; to prevent blindness & brain damage;
• Cystic fibrosis requires 400 IU/day or more because of poor absorption;
• Topical use as anti-inflammatory agent, in cosmetics, to heal wounds & to protect skin against UV& other damage; retard skin aging;
• Gamma tocopherol may inhibit prostate cancer & lung cancer.