Selenium deficiency and selenium supplements: Biological effects on fibrosis in chronic diseases, from animal to human studies

Selenium is a trace element, which is required for normal growth and development of animals and humans. It works by incorporating into proteins to make selenoproteins. These selenoproteins help to prevent free radicals from causing cellular damage, which may in turn lead to the development of various chronic diseases. Selenium deficiency, although is rare, can happen when the body does not have enough selenium. This chapter will review systematically the effects of selenium deficiency on fibrosis in various chronic diseases, such as cardiac fibrosis, liver fibrosis, kidney fibrosis, cystic fibrosis, thyroid fibrosis, oral submucous fibrosis, and pancreatic fibrosis in both animal and human studies. Moreover, their prevention and treatment with selenium supplement will be evaluated as well.