The kidney is an important organ of the human body. Its basic function is to produce urine to remove metabolites and certain wastes and poisons from the body, while retaining water and other useful substances, such as glucose and protein, through reabsorption to regulate water and electrolyte balance and maintain acid-base balance. The kidneys also have endocrine function, which is the degradation site of some endocrine hormones and the target organ of extra-renal hormones. These functions of the kidneys ensure the stability of the internal environment of the body and enable normal metabolism. Therefore, protecting the kidneys is vital to our health. Functions of normal kidneys: 1. excrete metabolites from the blood 2. maintain the balance of water in your body 3. participate in the control of your blood pressure 4. regulate the balance of electrolytes 5. regulate acid-base balance secrete biologically active substances, including from erythropoietin and active microbial D3, etc., keep hematocrit at normal value and maintain strong bones.