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Selenium Enriched Yeast 2000ppm

What Is Selenium Yeast?

Your body needs certain elements in very small amounts. These elements are called "trace elements." Selenium is a trace element. Some people do not get enough selenium and wish to take a selenium supplement. Selenium yeast is a dietary supplement that is used to increase the amounts of selenium in your diet. It is important to remember, however, that trace elements are essential in small amounts, but they can be toxic at high levels.


History

In 1957, a specific organic factor isolated from yeast was found to prevent a liver disease in rats apparently caused by selenium deficiency. That factor was later determined to be a selenium-containing amino acid known as selenomethionine. In the early 1970s, inorganic selenium-containing compounds, sodium selenite and sodium selenate, were approved by the U.S. Food and Drug Administration for use as feed additives. Unfortunately, these inorganic selenium salts were less effective than the organic selenium factor isolated from yeast. At that point, Universal Foods, a leading producer of food yeast, developed a process for producing selenium-enriched yeast. These selenium-rich yeasts were available for purchase in 1974. As of 2010, selenium yeast supplements are produced by many manufacturers providing selenium supplementation, not only for farm animals, but also for humans as well.

 

Composition

Commercial selenium yeast supplements contain from about 1,000 to 2,000 micrograms of selenium per gram of supplement. This selenium is in the form of selenomethionine, a specific selenium-containing amino acid. All amino acids occur in two different three-dimensional forms: an "L" form and a "D" form, which are essentially mirror images of each other. The human body can only metabolize the L-amino acid form. Synthetic selenomethionine supplements are also available, but they are slightly less effective than yeast-selenium. While synthetic versions contain more than 90 percent selenomethionine in the L-form, they also contain some selenomethionine in the D-form. Synthetic selenomethionine, containing mixtures of L- and D-forms, are suitable for use in animal feeds, but selenium yeast is preferable for human supplementation.

 

Quality Concerns

The quality of selenium supplements over the years has been questionable. Some selenium yeast products have been found to contain inorganic selenium instead of selenomethionine. Other supplement products contain "selenium proteinates" or "selenium amino acid chelates," which are chemically ill-defined. Supplements that contain both sodium selenite, an inorganic form of selenium, along and vitamin C may react with each other, causing the formation of elemental selenium, which may not be as beneficial to the body as the selenomethionine provided by selenium yeast.

Infants and Nursing Mothers

Although the benefits of selenium yeast for providing supplemental selenium are well known, many infant formulas, protein mixes and weight loss products still use inorganic sodium selenite or sodium selenate. Organic selenomethionine from selenium yeast is metabolized and utilized much more efficiently than the inorganic selenium salts. Selenium yeast supplements are both safe and effective for use, even in pre-term infants and nursing mothers.

Safety

The recommended dose for selenium for an average adult weighing 154 pounds is about 350 micrograms. A supplemental dose of 200 micrograms of selenium would increase the average selenium intake to about 280 micrograms per day, well-within the recommended amount. However, even prolonged exposure of up to 850 micrograms has not produced adverse effects. The lowest average daily selenium intake that could cause individuals to develop overt signs of toxicity is believed to be about 1,000 to 2,000 micrograms per day, but only after weeks or months of over-exposure. This would be quite rare and has only been seen with individuals taking inorganic selenium supplements, not with selenium yeast or selenomethionine products.

 

The European Community Scientific Committee on Food at one point did suggest that selenium yeast supplements are poorly characterized and can cause build-up of toxic selenium levels in tissues. However, these concerns were laid to rest in the British Journal of Nutrition in 2004, when a review of about one dozen supplementation studies showed no evidence of toxicity, even up to an intake level of 800 micrograms of selenium per day over a period of years.

 




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