Vitamin E is the antioxidant vitamin.
It’s really not a single compound but rather a group of individualized, fat-soluble compounds.
I see them as a mini-library of compounds, much as I see many of the redundancies Nature built.
Vitamin E is a group of similarly structured molecules.
Vitamin E or tocopherols are antioxidants that effectively scavenge lipid radicals.
Nutritional sources of vitamin E include fruit, oils, green vegetables, nuts, wheat germ, papaya, egg yolk, and liver.
Vitamin E molecules are divided into tocopherols and tocotrieoles. These two species of vitamin E have subspecies as well.
The role of vitamin E in health is to maintain the integrity of cell membranes. Vitamin E provides an enormous benefit to athletes during performance as well as recovery.
Healing, metabolism and immune function are all enhanced by vitamin E supplements.
Vitamin E is also important in energy metabolism, presumably as a protective aid to the electron transport system, which takes place in the mitochondrial membranes.
Vitamin E exerts a protective role in stabilizing biological membranes by inhibiting the peroxidation of membrane bound lipids.
Lipid radical formation is dependent upon electron transport activity, which increases dramatically during exercise.
It is believed that vitamin E is localized on mitochondria sites that are near to the sulfhydryl containing enzymes. These enzymes are coenzyme Q 10, the respiratory cytochromes and glutathione peroxidase. A powerfull group of enymes.
These receptor sites need protection because of the huge amount of lipids available for free radical conversion.
This close relationship affords these enzymes the protection against free radical attack and oxidation that vitamin E provides.
Vitamin E Recycling
Vitamin E helps prevent damage by neutralizing free radicals.
Lipid free radicals for example, which are formed during normal biological reactions, react with a neighboring vitamin E molecule thereby neutralizing them before they can damage cell membranes.
The tocopherol radical (Oxidized-E) formed, further reacts with vitamin C and other biofunctional compounds (selenium), to regenerate the original vitamin E molecule.
This mechanism explains the synergistic enhancement and recycling of vitamin E using the electron donor compounds of vitamin C, beta-carotene and selenium.
Mechanism of Vitamin E Activity
The antioxidant function of vitamin E is due to a specific hydroxyl (OH) group on the tocopherol molecule that binds with the carbon to oxygen double bond of phospholipids.
Phospholipids are important component of membranes. Vitamin E structurally enhances cell membranes by bonding between the methyl (CH3) group in vitamin E and the carbon-to-carbon double bonds of the unsaturated fatty acids present in the membrane’s phospholipids. These vitamin E to fat bonds, increase the viscosity of the membrane and decreases its permeability to cytotoxic compounds. This increases the protective mechanism of cell membranes and explains the importance of vitamin E.
Vitamin E and Muscle Activity
Muscle activity is dependent upon exact adjustments in calcium concentrations that are regulated through complex enzyme systems. These reactions depend upon ATP fueled pumps and membrane structural changes.
Vitamin E has demonstrated protective interactions on all the above, thereby helping facilitate muscular contraction and relaxation.