Selenium supplementation is a type of dietary intervention in which individuals increase their intake of selenium, a trace mineral that is essential for the proper functioning of the body. Selenium is known to have antioxidant properties and plays a crucial role in various biological processes, including thyroid function, immune response, and DNA synthesis. Research in the field of selenium supplementation focuses on the potential health benefits of increasing selenium intake through dietary sources or supplements. Studies have suggested that selenium supplementation may help reduce oxidative stress, inflammation, and certain chronic diseases, such as cardiovascular disease and certain types of cancer. However, it is important to note that excessive selenium intake can be toxic and may result in adverse effects, such as selenosis. Therefore, research in this area also aims to determine the optimal dosage of selenium for promoting health benefits while minimizing the risk of toxicity. Overall, selenium supplementation is a promising area of research that may offer potential benefits for overall health and well-being when balanced appropriately with dietary intake.