The time to stop taking vitamin C varies from person to person and needs to be considered in light of their own needs and whether they produce adverse reactions. Vitamin C is commonly used to treat scurvy and various energy-depleting diseases, and has antioxidant, vascular permeability-reducing, and lipid-lowering effects. If the body is deficient in vitamin C for a long period of time, scurvy may result. It should be noted that vitamin C can be taken appropriately for a long period of time, but should not be taken in excessive amounts for a long period of time. It is recommended to discontinue the drug promptly if adverse reactions occur, such as diarrhea and gastrointestinal disorders, allergic reactions, etc. In addition, excessive vitamin C can form oxalic acid, which can induce kidney stones, ureteral stones and bladder stones. Once there is percussion pain in the kidney area and redness in the urine, the drug needs to be stopped immediately and ultrasound examination should be performed promptly to exclude urinary stones. Vitamin C is abundant in fresh green vegetables and fruits, but vitamin C is not heat-resistant and is easily destroyed by excessive heating, so you can usually eat more of these foods and pay attention to the method when cooking. Secondly, people with poor kidney function should not take more vitamin C.