8 Facts About Selenium
elenium is an essential trace element that is nutritionally essential for humans. The micronutrient was first discovered in 1817 by a Swedish chemist, Jons Jacob Berzelius. The word ‘selenium’ is derived after the Greek word ‘selene’ meaning moon. Selenium is closely related in terms of chemical and physical properties with the elements sulfur and tellurium.
Selenium mainly exists as selenite and selenate (inorganic form) and selenomethionine and selenocysteine (organic form). Selenium’s importance to human health has been well-established. It is a constituent of more than 2 dozen selenoproteins that play critical roles in reproduction, thyroid hormone metabolism, DNA synthesis, optimal immune response, protection from oxidative damage, cardiovascular health, and cognitive health.
DIETARY SOURCES OF SELENIUM
The main sources of selenium in foods include brazil nuts, seeds, mushrooms, bread, garlic, yeasts containing selenium, asparagus, kohlrabi (enriched with this element), fish, seafood, meat, poultry, eggs, dairy products. Fruits and vegetables are characterized by a relatively low selenium content since as it primarily occurs in the protein fraction.
HOW TO GET ENOUGH SELENIUM?
For most people, getting enough selenium is as easy as consuming a couple of foods with selenium content in their daily diet.
Dietary supplements are needed for those who suffer from selenium deficiency, to raise low selenium levels or to maintain or improve selenium status. Moreover, the amount of selenium in soil or drinking water is not nutritionally significant in most geographic regions.
Did You Know? To get around 200mcg of selenium, you’ll need to consume 12 cups of dry roasted cashew nuts.
Selenium can be obtained from multivitamin/multimineral supplements and even as a stand-alone supplement.
While selenium is present in an organic form as selenomethionine in plant foods, selenocysteine dominates in the products of animal origin. Selenium in dietary supplements is available as selenomethionine, sodium selenite, or selenate.
ZENITH NUTRITION SELENIUM
Zenith Nutrition Selenium is a vegetarian dietary supplement that provides 200mcg of selenium in the form of Sodium Selenite.
The supplement is manufactured in a GMP-certified unit and has gone through extensive testing for assurance on quality and potency.
The capsules are free of sugar, preservatives, corn, soy, dairy, yeast, and gluten.
WHICH IS BETTER SELENITE OR SELENATE?
Selenite is a better form compared to selenate.
Selenium absorption happens within the duodenum of our small intestine. While selenite form gets absorbed by simple diffusion, selenate form would happen by a cotransport sodium selenate and exchange selenate/ OH− via an active transport sodium pump.
CAUSES FOR SELENIUM DEFICIENCY & SYMPTOMS
Those with compromised intestinal function, those who consume inadequate dietary intake of selenium, smokers, those of advancing age, people dependent on food grown from selenium-deficient soil are usually at risk of selenium deficiency.
Low selenium state in the body is associated with the following symptoms:
- Depressed mood, anxiety, confusion.
- Poor cognitive function
- Increased risk of thyroid disease
- Increased susceptibility to infections
- Hair may fall out faster than usual
- Skeletal muscle weakness
- May cause issues with infertility
WHAT IS THE RECOMMENDED DOSAGE OF SELENIUM?
The American Recommended Dietary Allowance (RDA) daily minimum requirement of selenium for optimal functioning is 70 micrograms (mcg) for men and 55 micrograms (mcg) for women respectively.
Free radicals are the natural by-products of oxygen metabolism that may damage cell membranes, DNA, and contribute to aging and pathogenesis of heart disease and neurodegeneration. Selenium deficiency further enhances oxidative damage to cell membranes. Low selenium status in the body could lead to an imbalance of antioxidants with an accretion of reactive oxygen species. Selenium supplementation provides potent antioxidant support which helps fight damaging free radicals. Glutathione peroxidase is a selenium-dependent enzyme that protects cell membranes and lipid oxidation.
SUPPORTS HEART HEALTH
Selenium supplementation protects your heart muscles from damage caused by free radicals, it fights inflammation by reducing the concentration of C-reactive proteins. Selenium acts as a cofactor for selenoproteins that have been identified in the regulation of glutathione peroxidases which help to neutralize reactive oxygen and nitrogen species. Optimum levels of selenium in the body would reduce the production of oxidized LDL and vascular inflammation which have been reported to be associated with inducing heart risk.
ESSENTIAL FOR NORMAL BRAIN FUNCTION
Our brain is vulnerable to damage caused by oxidative stress and selenium plays a significant role in brain health. Excessive free radical exposure has been associated with an increased risk of neurodegenerative changes. Selenium is said to offer great protection to brain health by playing a role in the synthesis of glutathione peroxidases, which are important antioxidant enzymes (reduce the concentration of reactive oxygen species) that protect brain tissues. It plays a chief role in the synthesis of selenoprotein which fights oxidative stress, protects brain cells, and helps prevent age-related cognitive decline.
HELPS IMPROVE FERTILITY
Although factors like diet, smoking, excess boy fat are major factors linked to reduced fertility in men and women, the trace element selenium is strongly linked to fertility. Testicular tissue is said to contain large concentrations of selenium and is responsible for sperm quality and male fertility. Selenium facilitates the morphology of sperm as well as its motility which are the key factors in normal conception. As a powerful antioxidant, selenium is known to protect sperm from oxidative damage. As per research, selenium is found to play a crucial role in the early stages of conception, increases progesterone, and plays a role in the development of healthy ovarian follicles in women.
BOOSTS IMMUNE RESPONSE
Selenium deficiency and suppressed selenoprotein levels result in higher levels of inflammatory cytokines and increased susceptibility to infections. Adequate amounts of an essential nutrient boost the functioning of T cells, and neutrophils. Selenium deficiency and suppressed selenoprotein expression have been implicated in higher levels of inflammatory cytokines in various tissues. Glutathione peroxidase, which is a selenium-dependent enzyme protects from peroxidative damage and regulates inflammatory mechanisms which when uncontrolled may be implicated in the pathogenesis of conditions like heart disease, arthritis.
MAY SUPPORT SKIN HEALTH
Due to its antioxidant and anti-inflammatory properties, selenium neutralizes damaging free radicals and fights inflammatory cytokines which eventually cause skin damage. Inflammation caused by UV-light exposure, poor immune response, stress are known to age skin, contributing to the breakdown of collagen. Studies emphasize the importance of selenium in protecting against skin inflammation and pigmentation. It is a powerhouse antioxidant for soothing inflamed skin, helps alleviate redness, and skin irritation. Supplemental selenium increases skin selenium content and increases antioxidant activity.
MAY IMPROVE THYROID HEALTH
The thyroid gland is characterized by the highest amount of selenium per gram of tissue (0.2–2 μg/g). Selenium is used there as a catalyst for building selenoprotein which is essential for converting an inactive T4 into its active T3. Selenoproteins contribute to the antioxidant defense in the thyroid by removing oxygen-free radicals. Selenium plays an essential role in the metabolism of thyroid hormone by incorporating into iodothyronine deiodinases (DIOs) and reduce hypothyroidism symptoms. Selenium deficiency is known to decrease the synthesis of thyroid hormones, as it decreases the function of selenoproteins.
PROMOTES LIVER HEALTH
Selenium functions as a great detoxifier by stimulating the production of glutathione peroxidase. It prevents excessive free radical stress linked to liver damage, helps maintain tissue elasticity in the liver, and also supports healthy hepatic circulation.