California Selenium supplements contain selenium in different chemical forms. In the majority of supplements, the selenium is present as selenomethionine. However, in multivitamin preparations, infant formulas, protein mixes, weight-loss products and animal feed, sodium selenite and sodium selenate are predominantly used.
Current evidence favors selenomethionine over the other forms of selenium.
Extradietary supplementation of selenium at the dosage of 200 micrograms per day is generally considered safe and adequate for an adult of average weight subsisting on the typical American diet.