Selenium is an essential trace element that can help prevent tumors and improve immunity. The Chinese Nutrition Society has listed selenium as one of the 15 essential nutrients, and relevant studies have shown that low selenium or selenium-deficient populations can not only prevent tumors, liver disease, etc., but also improve immunity and maintain the normal function of the liver, heart, lungs, stomach, and other organs by taking selenium supplementation in the right amount. And the elderly group to maintain adequate selenium can also reduce the occurrence of cardiovascular and cerebrovascular diseases. At the same time, most of the patients with liver disease have selenium deficiency in their bodies, and the more serious the disease, the more serious the selenium deficiency. There are also related studies show that hepatitis B is closely related to selenium deficiency. Liver disease patients with appropriate selenium supplementation, can also play a role in protecting the liver, promote the recovery of liver function, can also prevent liver fibrosis. In addition, selenium is also a natural antioxidant, can prevent gastric mucosal necrosis, promote local mucosal repair and ulcer healing, but also can prevent cancer. It is recommended to take selenium supplementation according to your own situation and understand the benefits of selenium to your body.