Home > Selenium dietary supplements - Dosage
Selenium has to be taken in dietary supplements in proper dosage in cases of nutritional deficiency.Selenium is an essential trace mineral required in small quantities for the normal and healthy functioning of human body.
In a typical diet in United States on an average 70 - 140 micrograms of this essential trace mineral is present.
Though this dosage is more than the Recommended Dietary Allowances (RDA), which is 55-60 mcg, its use in protection/treatment from conditions like cancers and heart diseases require higher concentrations.
People living in selenium deficient soils and sourcing locally grown food become chronically deficient and develop the deficiency diseases (see topic on selenium deficiency).In such specific conditions (found in China and Russia) they require to take the essential trace mineral in sufficient level to remain healthy.
Forms of selenium dietary supplementsMost of the present day multivitamin pills contain this essential trace mineral ranging in dosage between 30 - 200 mcg of of this mineral.
Apart from the dietary sources its dosage in multivitamin is more than sufficient.
This essential trace mineral in its elemental form it is not bio-available and it can become toxic on ingestion.
Selenium is available both in organic, chelated and inorganic forms.
Its inorganic forms like selenate and selenite have poor absorption rate and poor bioavailability.
selenium chelates and aspartates also have poor bioavailability.
Its organic form is selenomethionine which has greater absorption rate and bioavailability.
Selenomethionine exists in D- and L- isomer forms and the it naturally occurs as L-selenomethionine in foods.
'High selenium yeasts' contain a high dosage of 1000 -2000 mcg of this trace mineral per gram in the form of selenomethionine.
Synthetic selenomethionine was made in 1984 and is also available in dietary supplements.
Intravenous selenium forms are also available for treatment of patients in critical stage and on TPN (total parenteral nutrition) and the dosage has to be monitored by qualified health care professional.In its sulphide form it is being successfully used in the treatment of fungal infections like dandruff and tinea versicolor.
Selenium dietary supplements: quantity and quality concernsMany products are marketed with miraculous treatments for a number of ailments.
They usually contain high amounts of its inorganic salts and the quantity is not properly disclosed.
Some supplements are marketed as selenium yeast, but are made with yeast containing inferior inorganic selenate and selenite salts instead of selenomethionine.
Many of its chealate forms do not disclose the exact form of this trace mineral used in formulation.
Many infant formulations, protein foods and health products contain inorganic salts of this mineral whereas selenomethionine is the efficacious and preferred one over other forms.Excess of its salts in some formulations had caused selenosis (overdose of this essential trace mineral).
Safety factors in use of selenium supplementsWhen products of 200 mcg are taken, considering the food inputs, the total input increases in an adult to 250 to 400 mcg of selenium which is under safe levels.
The upper tolerance level is 400mcg for adults including sensitive groups.
In healthy individuals prolonged use of these products with dosage up to 800 mcg do not produce adverse effects.Overt toxicity symptoms appear when the lowest adverse effect level of 1500+mcg/day is exceeded.
Selenium dietary supplements: risk factorsThough the formulations of this essential trace mineral are safer in present days, decades ago accidental very high dosage had caused death of ponies and also selenosis in humans.
What is selenium.
Role in human nutrition.
Vanadium in diabetes.
Essential trace minerals.
Chromium in diabetes.
Good natural food sources.
Deficiency and symptoms.
Overdose and side effects.
Selenium dietary supplements and dosage (current topic).