Selenium is mainly absorbed in the small intestine, and the absorption rate of selenium in food is 60%~80%. Most of the selenium absorbed by the intestine is excreted through urine after metabolism. Urine selenium is a good index to judge the profit and loss of human selenium. Because there is no organ in the human body to store selenium for a long time, the selenium needed by the human body should be continuously obtained from the diet. The balance of selenium concentration plays an important role in protecting and promoting the physiological functions of many organs and tissues.
When selenium is deficient, it will easily lead to the decline of human immunity. More than forty diseases that threaten human health and life are related to selenium deficiency, such as cancer, cardiovascular diseases, liver diseases, cataracts, pancreatic diseases, diabetes, reproductive system diseases and other symptoms.