In the absence of vitamin E in animals occurs peeling skin, muscular weakness (dystrophy), disturbance of nervous system function, abnormal eye movements and reduced field of vision. There is a loss of reflexes, decreased muscle mass, loss of the ability of birth, the emergence of fragile (disturbed) erythrocytes. In gravid females of animals embryos can suffer and in males decreases production of sex glands.
In humans, vitamin E deficiency causes symptoms such as degeneration of the liver, diarrhea in which there is increased loss of fat and membrane disruption. No reliable evidence that vitamin E is essential for fertility in humans.
In vitamin E deficiency impair of many metabolic pathways occur, especially in muscles. The amount of myosin decreases and increases collagen.
In animals with vitamin E deficiency enhances oxidation of purine bases, resulting in the excretion of allantoin in large quantities.
Vitamin E deficiency can occur as a result of inadequate nutrition, but also in cases where there is a chronic disorder in the absorption of fat, in chronic liver disease and cystic fibrosis.
Overdose (hypervitaminosis, intoxication)
Vitamin E can be toxic in large amounts (more than 600 IU - International Units per day). In this case, bleeding and slow healing of the wound appears. People that use anticoagulation medication must consult a physician regarding the introduction of this vitamin in the body. This also applies to people who have low clotting factor, ie. people with vitamin K deficiency.
Excess of vitamin E can cause increased blood pressure. This was not observed in all subjects, and it is assumed that the increased pressure occurs only in people who are otherwise prone to increased pressure (hypertensive persons).
Excess of vitamin E can be very dangerous for people suffering from rheumatic heart disease.
Serious hormonal and lipid metabolism abnormalities may occur if there is too much of vitamin E in the body.