Selenium is an element with the atomic number 34 that was given the symbol Se in the chemical table. Like all elements in the periodic table, selenium has characteristics that are somewhere between sulfur and tellurium, the other elements from the same column. It is almost never found in pure form and ores that include elemental selenium are extremely rare. Selenium was discovered by J?s Jacob Berzelius in 1817. He noticed that the new element was similar to tellurium (meaning Earth), so he named it selenium (from the Greek word for Moon).
The best mineral sources of selenium are metal sulfides, where it can sometimes be found instead of sulfur. During the refining of such ores, selenium results as a valuable by-product. A few ores rich in selenium are also known, made up of selenate or selenide compounds, but these are extremely rare. It has a number of industrial uses, the most important today being in pigments and in the production of glass. As a semiconductor, it used to be valuable in the manufacturing of electronics but it has been replaced by silicon in this role. It remains an important raw material in the production of photocells.
Humans and all animals need very small amounts of selenium for the normal cell operations but selenium compounds can be poisonous in larger quantities. It is included in trace amounts in the usual food supplements, like multivitamins or products designed for infants.
Selenium is found in the structure of several important enzymes and bioactive compounds. It is part of glutathione peroxidase and thioredoxin reductase, two very important antioxidants that neutralize free agents in a number of animals and plants. In the human body, selenium is involved in the conversion of thyroid hormones, as part of three types of deiodinase enzymes. While some plants use no selenium at all, others appear to require sizeable amounts of this element.
Selenium is needed by the body in very low amounts but still plays a vital role in preventing heart diseases and cancer. Its effect appears to be stronger when combined with vitamin E and this formula can be found in many supplements. It plays a number of roles, one of the key ones being to neutralize free radicals and prevent the oxidation that can cause aging. When present in the skin, selenium contributes to faster healing of burns and other injuries. It is also involved in the metabolism of internal organs like testes, pancreas, kidneys, spleen or liver.
Selenium is known to reduce dandruff by eliminating the Malassezia fungus that produces it on the scalp. It is an important ingredient in many anti-dandruff shampoos, especially since it also increases the rate of hair growth. This element improves the absorption of proteins from food, giving the hair a stronger structure. Along with zinc, selenium is needed for several hormones that boost hair growth and cure a number of related issues. These include dandruff, hair breaking, baldness or premature greying.
While only needed in trace amounts, selenium is still extremely important. Since it is part of the structure of proteins, it is required in the process of growth. Selenium is also vital for cell regeneration and can decrease the effects of aging. It prevents numerous diseases that are connected with old age, like heart diseases, skin decay, cancer or effects of menopause. It is also a strong antioxidant.
This essential mineral keeps the skin moisture and flexible, delaying the signs of aging. As a powerful antioxidant, it stops free radicals from damaging cells and shields them from the destructive effects of sun radiation. Numerous age-related diseases are actually triggered by the oxidative damage caused by free radicals. Selenium forms an even stronger antioxidant combination when paired with vitamin E.
Since selenium is so beneficial for the skin, eating foods rich in this mineral can improve its health. It can be found in many products but the best sources of selenium are cereals (wheat, corn, oats and brown rice), meat (chicken, beef as well as organs like liver or kidneys), fish (herring or tuna), nuts (walnuts and Brazil nuts), cheese, eggs and many other food types.
Humans only need a relatively small daily dose of selenium, the RDA (recommended daily allowance) is about 55 micrograms. Other vitamins have a much higher RDA, of 15 milligrams or more. Selenium is available in supplements but these must be taken with caution, since the element becomes toxic if ingested in larger amounts than recommended.
Most of the benefits of selenium come from its antioxidant properties. It stops the action of free radicals, which are a by-product of cellular metabolism. This delays aging and can even prevent cancer, with great benefits for the skin since these are two of the most common issues. At skin level, selenium can inhibit infections and inflammation. Modern research has proven that eczema, psoriasis and a number of similar skin diseases of an inflammatory nature can be countered by selenium.
This element also increases the reaction of the immune system. It is especially valuable in stopping the symptoms of the incurable herpes virus, which can cause annoying sores. The anti-inflammatory action of selenium is stronger when combined with vitamin E. Together, these compounds can heal serious inflammatory issues like lupus, rheumatoid arthritis, eczema and psoriasis.
Selenium can also prevent the skin infections popularly known as acne. Acne emerges on the upper half of the body, especially on the face but also on the chest, back, neck and arms. It is caused by clogged skin pores that become infected. Selenium can prevent acne, so it is an ingredient in numerous dedicated creams and cleaning ointments.