Vitamin E
What is Vitamin E ?
Vitamin E is the name given to eight related, naturally occurring compounds, called tocopherols. While all the compounds play a role in animal health, alpha-tocopherol is the only one known to benefit humans. Vitamin E is fat-soluble (stored in the body, as opposed to being excreted in the urine).
What is the function of Vitamin E ?
Vitamin E is an antioxidant, which helps protect cells from the effects of free radicals, which can damage cells and are believed to speed the progression of cancer, cardiovascular and age-related diseases.
What are good sources of Vitamin E ?
Most of the Vitamin E found in the American diet is in the form of gamma-tocopherol, contained in vegetable oils. The best sources of alpha-tocopherol are nuts and seeds and their oils; peanuts, spinach, broccoli and mangos.
What is the recommended dosage of Vitamin E ?
The Recommended Dietary Allowance for Vitamin E is provided as both quantity (milligrams) and units of biological activity (International Units). For men and women age 14 and older, the established RDA is 15 mg/22.4 IU) per day.
How does Vitamin E deficiency occur ?
Vitamin E deficiency is rarely found, since so little is needed to maintain health, and it is easily obtained through diet. Because fat is required to absorb Vitamin E in the digestive tract, individuals with fat malabsorption disorders, cystic fibrosis or gastric diseases (such as Crohn's) may experience Vitamin E deficiency. Symptoms of deficiency include peripheral neuropathy, ataxia (loss of muscle coordination) and decreased immune system response.
What are the benefits of Vitamin E?
Studies indicate that Vitamin E may play a role in improving health and preventing and treating disease in four main areas: 1) lowering the rate of heart disease, 2) decreasing the incidence of certain types of cancer, 3) reducing the incidence of age-related macular degeneration and cataracts; 4) slowing the rate of onset of such neurological disorders as Alzheimer's disease.
It is important to note that these studies are preliminary and more clinical trials and validated results are needed.
What about Vitamin E supplements?
Vitamin E supplements are sold as natural or synthetic versions. The natural supplement consists entirely of alpha-tocopherol, while the synthetic is typically made up of all eight Vitamin E compounds, and is less expensive, but has less active, usable Vitamin E. When supplements are used, they are best taken with food for optimal absorption.
How much Vitamin E causes toxicity? What about drug interactions?
There is no research showing any adverse effects from consuming Vitamin E in dietary form. However, toxicity may occur when high doses of supplements are consumed. Symptoms of toxicity include hemorrhaging and difficulty with blood clotting. Possible adverse interactions can occur between Vitamin E and anticoagulant medications, other antioxidants and vitamins, some cholesterol-lowering drugs and some chemotherapy treatments.
Tolerable upper limit intake for Vitamin E has been established at 1,000 mg/1,500 IU per day for men and women age 19 and older.
