Test Details: Selenium is an important antioxidant which regulates thyroid hormone, improves reproduction and helps in DNA synthesis. . Selenium deficiency targets cardiac muscle leading to Cardiomyopathy. This assay is useful for monitoring Selenium replacement therapy specially patients with no functional bowel, on parenteral selenium supplementation. Selenium adsorbed in the human body is excreted mainly by urination,24 hours Urine sample is the preferred specimen type for the assessment of selenium toxicity and deficiency