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PROMOTES Anti-Inflammatory Activity Immune Function White Blood Cell Production Detoxification Thyroid Function Vitamin E Utilization
PROTECTS AGAINST Premature Aging Cardiac Inflammatory Disorders Other Inflammatory Disorders Heavy Metal Toxicity Lowered Thyroid Hormone Cataracts
The RDA for selenium for Adults ranges from 55 to 75 micrograms (MCG) a dayminimum. Suggested daily dosing is 200 to 400 mcg a day.
Overview Selenium, a non metal, chalcogen element, was discovered in Sweden in 1817 by J. J. Berzelius. It is number 34 on the atomic periodic table.
Selenium, an essential trace micro mineral, was thought to be totally toxic. Over the past half century, it has been found to be key in antioxidant enzymes. These enzymes are made up of selenium proteins which are important in detoxification of free radicals and thus play a role in the prevention of chronic diseases. They provide some of the defense mechanisms of the immune system.
Selenium also helps regulate thyroid function.
The forms that are available for supplementation include organic and inorganic compounds. The organic compound and the one thought to be best absorbed and utilized in the body is selenomethionone, an analogue of the amino acid methionine. Another seleno amino acid is selenocysteine. There are some specialty yeasts that have as much as 2000 micrograms of selenium per gram and most of the selenium here is the organic compound. Most supplements of selenium are made up of, in total or part, the inorganic sodium selenite and sodium selenate. These are bioavailable, but to a lesser degree.
Selenium deficiency is rare in the U.S. as most of the areas of the North American continent has selenium in the growing soil although farming practices can deplete this. China has had high rates of selenium deficiency primarily because of the low levels of selenium occurring naturally in the soil.
The Keshan district of China had high rates of childhood cardiomyopathies (enlarged, poor functioning hearts) until selenium supplementation was started. This type of cardiomyopathy is called Keshan Disease and research indicates a certain viral infection in the presence of low selenium levels may cause this.
Another condition of selenium deficiency is Kashin-Beck Disease. This is a degenerative joint disease called an osteoarthropathy and progresses with crippling effects.
Another syndrome from selenium deficiency is myxedematous endemic cretinism. This results in mental retardation.
Severely injured persons or those suffering major intestinal inflammation may have interference with selenium absorption and resultant deficiency. Those on total parenteral nutrition (intravenous feeding) need selenium and other micronutrients added in forms that are compatible with blood components.
Selenium is depleted by steroids
Processing removes significant amounts of selenium from grain based foods.
All plant foods grown in selenium rich soil. Selenium in food varies depending on the region from which it was grown and harvested. Whole grains are the best source. Dairy products and eggs as well as seafood and liver are good animal sources. Brazil nuts can be extremely high in selenium content.
None known.
Selenium's function in the body has:
-Anti-inflammatory effect that is provided by glutathione peroxidase, an important selenoprotein enzyme.
-Antioxidant effect of glutathione peroxidase which is powerful, one of the most effective antioxidant enzymes of the immune system.
-Anticarcinogenic activity by preventing free radical damage to DNA and RNA within the nucleus of cells.
-Antiviral effect by boosting certain white blood cells - the T lymphocytes and natural killer cells.
-Detoxifying properties that reduce the effets of damaging ions from heavy metal and some cancer chemotherapeutic agents.
-Thyroid hormone conversion activity changing thyroxin (T4) to triiodothyronine (T3). This conversion is mediated by a selenoprotein enzyme called deiodinase.
-Vitamin E potentiation, boosting it's antioxidant activity.
A diet for infants of strictly cow's milk with no supplementation will result in low selenium levels and resultant deficiency syndromes. Cow's milk has 60% less selenium than human milk.
White rice has approximately 1500% less selenium than brown rice.
A diet rich in selenium or selenium supplementation may help to decrease the risk of cancer because of its role in DNA repair. It may also help prevent heart disease and help to control asthma symptoms.
Recommended Dietary Allowance:
1989 Recommended Dietary Allowances (RDA) National Academy of Sciences
AGE (YRS) AMOUNT in micrograms
Infants 0.0-0.5: 10 0.5-1.0: 15
Children 1-3: 20 4-6: 20 7-10: 30
Males 11-14: 40 15-18: 50 19-24: 70 25-50: 70 51+; 70
Females 11-14: 45 15-18: 50 19-24: 55 25-50; 55 51+: 55
Pregnant: 65
Lactating 1st 6 mos.: 75 2nd 6 mos.: 75
Blood levels of selenium that exceed 100 microgram (mcg) per deciliter cause risk of a condition called seleninosis. The symptoms are: -Nausea/Vomiting -Diarrhea -Fatigue -Irritability -Hair Loss -Brittle Blotchy Nails -Halitosis -Could lead to Neurological damage.
One incident of manufacturing error led to excess amounts of selenium in a supplement which was many times greater than the label intended. Industrial accidents have caused excessive amounts of selenium and toxicity.
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