The main role of the vitamin E in the body is as an anti-oxidant at the cellular level. The action of the vitamin E protects fatty acids or oils against the degradation induced by oxidation and rancidity in the human body. All cells and sub-cellular membranes in the human body have a sizeable portion made from fatty acids, these membranes and cellular regions require protection against oxidation - thus the anti-oxidant action of the vitamin E is one of the most important actions carried out in the body by any nutrient. Several important roles are served by these fatty acids in the human body - these fatty acids are normally polyunsaturated, however, most scientists believe that oxidation causes many diseases and also brings on some of the physical symptoms associated with aging.
During a state of deficiency of the vitamin E, there is general impairment in many vital enzyme systems operating in the human body. At the same time, the exact function of the vitamin E in any specific enzymatic reaction has still not been discovered. This impairment in the functioning of the enzyme systems may possibly be due to oxidation or peroxidation of the tissue components in the enzyme system according to some scientists.
Several clinical studies conducted on red blood cells in the human body have demonstrated the protective actions of the vitamin E at the cellular level. In one of these studies, a group of people were made to take about 600 IU of the vitamin E daily for a supplemental regimen lasting ten days. Following this, the volunteers were tested for the ability of their red blood cells to resist the impact of oxidative "aging" especially when the cells were exposed to light and to excess oxygen levels at the cellular level. While only about eight percent of people in the supplemented group got budded red blood cells, all the red blood cells taken from people who were given supplements were completely budded - this term refers to oxidative damage in the cell.
Red blood cells age and tend to turn less filterable over time. However, in one clinical study carried out on rats, it was found that supplements of vitamin E improved the ability of red blood cells in animals and made them extremely resistant to the aging effect at the cellular level that occurs in cases of lead poisoning. At the same time, all the red blood cells gathered from rats given supplement of the vitamin E that were also poisoned using lead turned out to be still more filterable than the red blood cells sourced from animals that were fed absolutely no lead but which also received a diet that was deficient in its content of vitamin E. There was also no significant difference in the filterability of normally aging red blood cells sourced from animals given supplements of the vitamin E.
A great increase in the susceptibility of the red blood cells cystic fibrosis patients with vitamin E deficiencies to abnormal oxidative destruction has also been noticed by many clinical researchers. None of these patients developed symptoms associated with anemia, even when all the biochemical signs suggestive of an increased destruction of the red blood cells were observed. The survival rate of red blood cells was returned to normal rates on the use of vitamin E supplements ranging in doses from 100 to 200 IU. The conclusion that the clinical researchers made was that the vitamin E was essential to the maintenance of normal cell structure and functioning of red blood cells.
Degeneration in the gonads of rats suffering from a deficiency of the vitamin E is one of the first symptoms usually detected in animal experiments, one major impact of this primary symptom is that it leads to a complete loss of sperm motility in the male rates and induces fetal death and resorption in the female rats. The next affect is impairment in the functioning as well as an impact on the ability to secrete enough sex hormones; these changes accompany the degeneration of the sex glands and also affect many other processes in the body of the organism. The process of puberty and development can be adversely affected by a vitamin E deficiency in a growing organism.
An impairment in the functioning of the pituitary and thyroid system is also often observed in organisms experiencing a prolonged state of vitamin E deficiency. The requirements of the vitamin E also tends to increase during a hyperthyroid state of functioning of the thyroid, one effect in this condition is an increase in the blood levels of fatty acids and as more fatty acids are found in the muscles, especially in the muscles of the heart, vitamin E needs to be present in higher amounts to protect against increased oxidation during an increase in the fatty acid levels.
During a state of vitamin E deficiency in the body, there is general degeneration and dystrophy in the skeletal, the striated as well as the cardiac muscles of the body. Some clinical reports also report instances of degeneration in the endocrine glands, as well as problems in the peripheral vascular system and the nervous system in general. Nervous system lesions formed during a state of vitamin E deficiency in some animals can take the form of softening the tissues of the brain -resulting in loss of nervous coordination and control.
In human beings, the only widely recognized side effect of a deficiency of vitamin E is a general decline in the survival time of red blood cells in the blood. This situation can come about even with only a partial deficiency of the vitamin E in the body as shown during tests. In some of these tests, the volunteers received 5 IU of vitamin E daily but were still affected by a general decline in the survival time of red blood cells. There is also a general absence of rigorous biochemical testing on the effects of such a state of deficiency on other cell systems in the body - some of these cell and tissue systems may have been much more severely affected than the red blood cells. Children who are deficient in the vitamin E are also reported to be affected by a general degeneration of the brain and spinal cord and may suffer a generalized loss of nervous system functioning.
Vitamin E or tocopherol comes in more than one chemical form. At the very least, four types of tocopherols have been isolated in the laboratory, these are the alpha form, the beta form, the gamma form and the delta form of tocopherols. The alpha form of tocopherol is the most active of all the chemical forms of the vitamin E and is the main type of vitamin E supplement. In addition, the vitamin E activity - given in international units or IU - is calibrated on the amount of alpha tocopherol present in the supplement. The supplements of synthetic vitamin E are termed synthetic alpha tocopherol. Vitamin supplements available in the market contain the natural form of the vitamin E often labeled d-alpha tocopherol; the synthetic dl-alpha tocopherol is also widely seen in these supplements. The most potent form of the vitamin E is the natural form of vitamin E found in many food sources. At the same time, the difference in the potency of this vitamin is accounted for while calculating the total "activity" of the vitamin E in international units. This is the reason that a vitamin E supplement of about 100 IU of the d-alpha form of the vitamin will be as potent as a 100 IU of the dl-alpha form of tocopherol. While both forms are chemically identical, a single researcher claims that the natural form and the water soluble form of vitamin E were on the whole better at raising the amount of vitamin E in the blood compared to the synthetic form of the vitamin. These results were obtained from persons affected with lupus erythematosus - an auto-immune disorder. Healthy individuals show no different effects from the use of different forms of the vitamin. Not surprisingly, many clinical studies show, that similar doses of either the natural or the synthetic form of vitamin E will induce the same levels of tocopherol to be found in the blood and the tissues levels of tocopherol, once these have been adjusted for the major differences in the potency of reactions. The standard form of the vitamin E used in most of the clinical studies and therapeutic uses mentioned above is the synthetic form of tocopherol.
No significant amounts of the vitamin E are destroyed or degraded due to cooking. However, vitamin E in foods can be degraded during frying, particularly when using deep fat, this form of cooking can cause generalized oxidation of most of the vitamin E contained in the food. Vitamin E contained in foods can also be destroyed on storage of the vitamin for long periods of time.
A wide range of dosages of supplemental vitamin E are available in the market, these range from a few IU to more than 1000 IU per tablet or capsule. The oils found in the seeds or cereal grains have the highest natural stores of the vitamin E. The greatest amount is seen in wheat germ oil, this is followed by soybean oil, then by cottonseed oil, then by sunflower seed oil, then by corn oil and so on. Considerably smaller amounts of the vitamin E are found in various nuts, in eggs, fish and different organ meats. Though high in vitamin E content, many fruits and vegetables are not normally consumed at the levels required for them to supply sufficient amounts of vitamin E - and they are therefore not seen as significant sources of the vitamin. While they can occur, very few people ever suffer from a severe deficiency of vitamin E.
For most healthy people, the RDA with respect to vitamin E have now been lowered from a maximum of 30 IU per day to 15 IU daily. The RDA of vitamin E for men is now at 15 IU, while it is 10 IU for most women. One of the main reasons that the RDA of this vitamin was lowered was that the dieticians often complaining about the difficulty, or perhaps the total impossibility of creating diets that supplied 30 IU of vitamin E to a person on a daily basis. What is not surprising about this is that most people consume a lot of wheat as the main dietary carbohydrate, and the refining of flour results in the elimination of most of the vitamin E found in wheat. A very significant amount of the caloric requirement of the average person is made from white flour products that are essentially devoid of all vitamin E - because the vitamin is not replaced by a process of vitamin fortification during the processing of food products. The current RDA for the vitamin has been criticized by several authorities on vitamins, these include the researcher who actually conducted the only human deficiency study on the vitamin E - these critics maintain that the RDA for the vitamin E is too low and cannot be expected to help in maintaining the vitamin E status in the body at an adequate level.
While most of the supplements used by common people are thought to be very safe and without side effects, there are rare instances of vitamin E toxicity from long term supplemental use of the vitamin.
The requirements of the vitamin E in the human body are increased by the long term consumption of a diet that is high in unsaturated fats. Fat soluble parts of the body are protected together by the combined actions of the vitamin E and the essential mineral selenium.