SELENIUM
The name Selenium comes from the ancient Greek moon goddess Selene. It was discovered for the first time in the early 1800s by the Swedish Jöns Jakob Berzelius, who is considered one of the founders of modern chemistry. Selenium; It is found dissolved in air and water, as well as in solid form in soils and rocks. Thus, it passes to plants, fungi, bacteria and humans from here, and then returns to nature. Its average concentration in nature was found to be 0.09 ppm. Se concentration in the blood is 60-100μg/l. One slice of whole wheat bread contains 10 micrograms of selenium. Selenium is abundant in foods such as walnuts, meat, offal, fish and shellfish, whole wheat flours, dairy products, vegetables and fruits, and eggs. The fact that selenium is essential for the human diet was unknown until we discovered the association between low selenium concentration and Keshan disease. This juvenile cardiomyopathy, commonly seen in China, has caused the death of many children and has been completely cured by administration of 0.5-1 mg Se per week. Selenium is found in all human tissues, especially liver and kidney. As a result of recent studies, it has been evaluated as an important and useful element for biological systems. There are many other diseases associated with selenium in humans. These include arthritis, cataract, cystic fibrosis, muscular dystrophy, phenylketonuria, Down syndrome, bronchopulmonary dysplasia, hemolytic anemia, multiple sclerosis, night blindness, defective immune response, malaria, Kwashiorkor and sudden death syndrome in the newborn. Selenium also prevents liver necrosis seen in vitamin E deficiency in rats. Selenium is found in the structure of the antioxidant glutathione peroxidase enzyme, which plays a role in the prevention of some metabolic diseases and cancer types. The biological importance of selenium is that it is a co-factor of this enzyme. Glutathione peroxidase, which contains a Selenium atom in the form of selenocysteine in each subunit, plays a role in the reduction of hydrogen peroxide (H2O2) to water in the cell. Selenium interacts with vitamin E and protects the cell membrane from oxidative damage caused by peroxides formed as a result of lipid metabolism. The evidence for a link between low Selenium intake and an increased risk of cardiovascular disease is weak. It has been shown that selenium may be protective against some types of cancer, increase male fertility, reduce cardiovascular mortality, and suppress the production of inflammatory mediators in asthma.
SELENIUM AND THYROID
Most of the biologically active T3’s in tissues, cells and circulation are formed from T4 in a reaction catalyzed by the selenium-dependent iodothyronine deiodinase enzyme. For the first time in 1987, Goyens et al. found that serum selenium and glutathione peroxidase levels were low in cretin children in the endemic goiter region of Africa and stated that toxic oxygen damage and selenium deficiency in these children may lead to thyroid gland destruction. In addition to its anti-inflammatory effect, selenium is also found in the structure of the antioxidant glutathione peroxidase and thioreduxin reductase enzymes. In a study conducted in Turkey, it was shown that iodine and selenium deficiencies in school-age children and these negatively affect thyroid hormone levels. In areas of iodine deficiency, selenium should not be given until the iodine deficiency is corrected. in a study abroad. With a daily intake of 200 mcg selenium for 3 months, serum Anti-TPO levels decreased by 36% in the Selenium group and 12% in the placebo group. It can be used as an adjunct therapy in autoimmune thyroid diseases with high selenium antibodies.
