Vitamin C can be taken for a long time, but it must be used in accordance with medical advice and the dosage specified in the instructions, and do not overdose. Vitamin C is an important vitamin for the organism, which can be used to prevent scurvy, and can also be used as an adjunctive treatment for various acute and chronic infectious diseases and purpura. If the patient does not have indications for medication, then long-term use of vitamin C is generally not recommended. For healthy people, if they can eat a balanced diet, then they can get enough vitamin C from food and there is no need for additional supplementation. Excessive intake of vitamin C may cause some damage to the body, such as long-term excessive intake of vitamin C, scurvy may occur after discontinuation of the drug, it may also lead to the formation of urate and cysteine stones or diarrhea, nausea, vomiting, redness of the skin and other related symptoms. Vitamin C, although relatively safe as a vitamin supplement, needs to be used under a doctor’s supervision. Especially in the case of long-term use, it is important to have clear indications and to avoid overdose.