Preferred Nutrition SelenIUM - 200 mcg - The form of selenium within the diet has an important influence on absorption. L-selenomethionine is readily absorbed from the gastrointestinal tract and is significantly better absorbed and retained in the body than inorganic selenium in the form of selenite or selenate. Organic forms of selenium, such as selenomethionine, are selenium bound to methionine, an essential amino acid. Those persons with low nutritional selenium status have an increased risk of cardiovascular disease and high rates of cancers.