VITAMIN E
Vitamin E is made of a group of fat soluble compounds which posses distinctive antioxidant activities(13)
THE VARIOUS FORMS OF NATURAL VITAMIN E: There are 8 forms: Tocopherol: Alpha- (a-), beta- (b-), gamma- (g-). delta-(d-)Tocotrienol: Alpha- (a-), beta- (b-), gamma- (g-), delta- (d-).
These all have varying levels of biological activity.
RRR-alpha-tocopherol (commonly labeled as d-alpha-tocopherol) (13) is naturally sources and the most active and bioavailable form and predominant in human tissues. (12)
dl-alpha-tocopherol is synthetic vitamin E and may be harmful
Vitamin E is found in certain foods, while it can be added to others and is also available in the form of a dietary supplement. (13)
Many studies have identified consistently lower than normal levels of vitamin E in children with autism. (6)
STORAGE
High levels of vitamin E are stored in the adipose tissue, and in various organs.
OPTIMAL LEVEL
400 IU to 800 IU mixed tocopherols
ASSISTANTS
Coenzyme Q-10 (CoQ10): assists vitamin E in maintain its antioxidant state.
BENEFITS
Vitamin E is essential for our vision, reproduction and the health the blood and skin. (4).
It is also essential for tissues with a high concentration of fat by preventing preventing lipid peroxidation and thus supporting cell membranes and neurones. (6)
They are anti inflammatory and thus can help in the neurological and meta disorders (immune function, cell signaling, regulation of gene expression as well as those relating to aging. (14)
DEFICIENCY
Vitamin E deficiency may result due to fat malabsorption. Deficiency symptoms include (13):
Muscle weakness
Loss of muscle mass
Abnormal eye movements
Vision problems
Unsteady walking
Long-term deficiency may result in liver and kidney problems.
Supplementation might be required in people with digestive disorders, including chronic bowel disease, Crohn's disease, cystic fibrosis or those who have difficultly in secreting bile from the liver to the digestive tract. (They require water-soluble forms of vitamin E, such as tocopherol polyethylene glycol-1000 succinate) or those who have undergone gastrointestinal surgeries (13)
People with a rare inherited disorder. abetalipoproteinemia, which results in poor absorption of dietary fat, require enormous doses of supplemental vitamin E (approximately 100 mg/kg or 5-10 g/day) (13)
Inherited disorders in which the liver's a-tocopherol transfer protein (a-TTP) is defective or absent or there are decreased levels of melanoproteins are more likely to become vitamin E deficient (20)
ABSORPTION
Vitamin E absorption into the intestinal lumen is low, and dependent upon the liver. It depends upon the
1. Biliary and pancreatic secretions
2. Uptake into cells of the intestinal lining (enterocytes) and 3. Chylomicron secretion.
Blood and cellular concentrations of alpha-tocopherol are the highest Vitamin C aids in the activity of vitamin E as an antioxidant by regenerating back to it active form (14)
Bioavailability and bio equivalence of the different forms of vitamin E differ.(14). Uptake varies between different individuals.
This may be due to variations in a-TTP activity, metabolic rate, dietary lipid content are composition, the status of other micronutrients that recycle a-tocopherol and environmental conditions. (14)