Selenium



Selenium is an essential mineral and micronutrient which is required in very small amounts in the body. Despite the fact that we don't need much of it, the importance of required selenium intake in daily diet is fundamental to overall human health.

Selenium is incorporated into proteins to make selenoproteins, which are important antioxidant enzymes. Selenium promotes the release of an enzyme called glutathione peroxidise, which can eliminate peroxides that destroy essential lipids. Selenium also works in conjunction with vitamin E, vitamin C, glutathione and vitamin B3 as an antioxidant to prevent free radical damage in the body.

Brazil Nuts, sunflower seeds, fish (tuna, halibut, sardines, flounder, salmon), shellfish (oysters, mussels, shrimp, clams, scallops), meat (beef, liver, lamb, pork), poultry (chicken, turkey), eggs, mushrooms, grains (wheat germ, barley, brown rice, oats) and onions are generally considered good sources of selenium. It is also important to note that selenium content in foods depends on the concentration of selenium in the soil where the crops were grown.

Selenium is mostly found in the liver, kidney, testes, pancreas and spleen. There is a physiological range of selenium in the body which is around 70-90 ng/ml which corresponds to an amount of selenium of about 50 µg per day. World Health Organization (WHO) RDA for selenium is 70 micrograms/day to 350 micrograms/day depending upon the soil and water concentrations of selenium in different regions accross the world.

Weakened nutrient absorption as in Crohn's disease or ulcerative colitis, toxins from poor diet, pollution, medications, stress, aging, smoking and drinking all deplete your selenium. A deficiency in selenium can lead to improper functioning of the thyroid gland, heart disease, pain in the muscles and joints, unhealthy hair, and white spots on the fingernails.

Heart Disease
Keshan disease, which results in an enlarged heart, heart arrhythmias, loss of heart tissue and poor heart function, occurs in selenium deficient people. Atherosclerosis, or hardening of the arteries can also be worsened with selenium deficiency.

Rheumatoid Arthritis
Dietary deficiency of selenium has been show to be a contributing cause in rheumatoid arthritis, where oxidative stress damages the area inside and around the joints. A deficiency of selenium and iodine is also considered common in Kashin-Beck disease or Osteoarthritis deformans - articular cartilage, epiphyseal cartilage degeneration in children.

Myxedematous Endemic Cretinism
This disease results in mental retardation in infants born to mothers deficient in both selenium and iodine.

Thyroid Disease
Conversion of T4 to T3, as deiodinase enzymes (those enzymes that remove iodine atoms from T4 during conversion) are selenium-dependent. Adequate selenium nutrition supports efficient thyroid hormone synthesis and metabolism. In cases of severe selenium deficiency, conversion of T4 to T3 may be impaired, leading to hypothyroid symptoms. Selenium also helps protect against a goiter, which is the enlargement of the thyroid gland, and mask a few of the neurological effects associated with iodine deficiency.

Asthma
Evidence suggests that people with asthma tend to have low blood levels of selenium. In a study of 24 people with asthma, those who took selenium supplements for 14 weeks had fewer symptoms compared to those who took placebo.

Brain
Selenium plays a part in the manufacture of brain chemicals known as neurotransmitters, and low levels of selenium in the elderly are linked with an increased risk of dementia and senility.

Reproductive Health
Selenium has long been used in the world of animal husbandry to prevent miscarriage. Women prone to miscarriage tend to have low levels of selenium in their systems. One study demonstrated that supplementation with this nutrient increased fertility in a group of men with poor sperm quality.

Immune Booster
Selenium is an important nutrient vital to our immune system's functioning. Selenium, along with other minerals, can help build up white blood cells, which boosts the body's ability to fight illness and infection.

Cancer
Selenium is known to have potent antioxidant activity it stimulates the immune system, and so appears to help the body kill off very early tumours. Since the Seventies it has been noted that individuals with the lowest intakes of selenium have the highest risk of dying from cancer. Selenium has been shown to induce DNA repair and synthesis in damaged cells, to inhibit the proliferation of cancer cells, and to induce their apoptosis, the self-destruct sequence the body uses to eliminate worn out or abnormal cells. In 1996, a scientific study was published which demonstrated selenium's ability to halve deaths due to some cancers.

Precautions
Extremely high doses of selenium can be toxic. Side effects include fingernail loss, skin rash, fatigue, irritability, weight loss, risk of diabetes and high cholesterol. People who have had, or are at risk for, skin cancer should not take selenium without talking to their doctor.

Always consult your health care provider before starting a supplement therapy