Selenium is useful for the human body to improve immune function, protect the liver and improve eye diseases. 1. Improve immune function: Selenium is a potent immunomodulator, selenium supplementation can enhance the body’s immune function and reduce the risk of viral infections. If the body has a disease, selenium supplementation can also stop the aggravation of the disease, alleviate the discomfort symptoms, and facilitate the recovery of the body. Improve the ability of immune system cells to phagocytose and sterilize, thus improving the body’s immune function. 2. Liver protection: Selenium has a strong protective effect on the liver. Selenium is a strong antioxidant, selenium supplementation can increase the activity of selenium-containing enzymes in the body, improve the body’s antioxidant function and promote liver recovery. 3. Improve eye diseases: Selenium can improve eyesight and prevent eye diseases. Selenium can protect the retina, enhance the vitreous humor and improve eyesight. Long-term lack of selenium in the eyes will result in vision loss and eye diseases, such as cataracts, retinopathy, pseudomyopia, and so on. Selenium is an indispensable trace element in the human body, patients with selenium deficiency are recommended to take relevant medications for selenium supplementation as prescribed by the doctor, such as selenium yeast tablets, sodium selenite tablets, and so on.