Selenium Deficiency
Selenium deficiency is most commonly seen in parts of China where the selenium content in the soil, and therefore selenium intake, is very low. Selenium deficiency is linked to Keshan Disease.
The most common signs of selenium deficiency seen in Keshan Disease are an enlarged heart and poor heart function.
Since the etiology of the disease was unknown, it was given the name Keshan disease after the place her where it was first discovered.
Keshan disease has been observed in low-selenium areas of China, where dietary intake is less than 19 mcg per day for men and less than 13 mcg per day for women.
This intake is significantly lower than the current RDA for selenium. Selenium deficiency also may affect thyroid function because selenium is essential for the synthesis of active thyroid hormone.
Researchers also believe selenium deficiency may worsen the effects of iodine deficiency on thyroid function, and that adequate selenium nutritional status may help protect against some of the neurological effects of iodine deficiency.
Selenium deficiency has been seen in people who rely on total parenteral nutrition (TPN) as their sole source of nutrition.
TPN is a method of feeding nutrients through an intravenous (IV) line to people whose digestive systems do not function.
Forms of nutrients that do not require digestion are dissolved in liquid and infused through the IV line. It is important for TPN solutions to provide selenium in order to prevent a deficiency.
Physicians can monitor the selenium status of individuals receiving TPN to make sure they are receiving adequate amounts.
Severe gastrointestinal disorders may decrease the absorption of selenium, resulting in selenium depletion or deficiency.
Gastrointestinal problems that impair selenium absorption usually affect absorption of other nutrients as well, and require routine monitoring of nutritional status so that physicians can recommend appropriate treatment.
Selenium deficiency and other other disease
Selenium deficiency ,may also be related to several other health condition. A low selenium status has been linked with an increased risk of pre-eclampsia and spontaneous abortions.
A number of studies have found evidence that an adequate supply of selenium is essential for male fertility.
Selenium deficiency has also been linked to the occurrence and severity of viral infection. It has been shown, under experimental conditions, that severe selenium deficiency in vitamin E-deficient hosts can change the mutation rates of RNA viruses, such as influenza, measles hepatitis and HIV, and thus increase their virulence.
It has shown that a mild strain of influenza virus exhibit increased virulence when given to selenium deficient mice and that this is accompanied by multiple changes in the viral genome in a segment previously thought to be relatively stable.
