Selenium is an essential trace mineral crucial for human health, primarily acting as a powerful antioxidant. It plays a vital role in the body's immune function, aiding in the prevention of chronic diseases and supporting thyroid health. Sufficient selenium intake has been linked to reduced risks of certain cancers and improved reproductive health. Moreover, it works synergistically with other nutrients, such as vitamins E and C, to combat oxidative stress. However, both deficiency and excess intake can lead to health issues, underscoring the importance of balanced nutritional consumption.