The biological functions of selenium are for example, conversion of hydrogen peroxide to water in thyroid gland, degradation of free radicals, the lipid peroxidation of cell membranes, which is enhanced by vitamin E. It helps to strengthen the immune system, prevent cardiovascular disease, protect the skin, eyes and hair, reduce the risk of cancer, especially in the gut, lungs and prostate. Muscles and the liver provide the brain and endocrine glands (pituitary, thyroid and sex glands) with the selenium, which uses it in their functions. It is excreted almost completely with urine and feces. A small portion is excreted with sweat and saliva. Lack of selenium can cause heart disease, muscle weakness, changes in skin pigment and pancreatic damage.
Selenium is toxic in large amounts and can cause stomach pain, diarrhea, nausea, irritability, fatigue, dermatitis and alopecia. A sign of too much selenium is a characteristic odor of garlic in sweat and exhaled air.
The daily requirement of an adult is approximately 55 mcg. Selenium is naturally found in: viscera, fish, clams, meat, milk and milk products; beer yeast, cereal sprouts, pasta (especially if made from durum wheat), rice; mushrooms, nuts, garlic, fruits and vegetables in general.
Selenium is also a fundamental element of the body and has great anti-cancer properties, especially against prostate cancer. The modern eating habits of the western population have drastically reduced the intake of selenium through food. Selenium is essential for the enzymatic reactions responsible for glutathione synthesis, a powerful, natural and endogenous antioxidant molecule found in all cells. A deficiency of selenium in the food leads to immunosuppression (to a reduced resistance to infectious diseases), the body’s reduced antitoxic ability and degenerative diseases, as well as cancer.