Selenium 200 mcg - Yeast-free chelated amino acid complex that provides stability and superior absorption and supports the immune system, healthy thyroid and metabolism. Immune System, Thyroid & Metabolism Support: Selenium naturally supports the immune system, healthy thyroid and prostate function. Selenium may also play a key role in the metabolism of both men and women. Chelated Super Absorbent Selenium: By using the leading manufacturer of chelated minerals, Selenium 200 MCG provides ease of absorption, stability, and overall quality. Yeast-Free Essential Micronutrient Selenium Amino Acid Complex: Selenium is a naturally occurring micronutrient that may play an important role in many essential body functions.