It is not recommended that the elderly take a tablet of vitamin C a day for a long period of time, as long-term use can cause urate and oxalate stones, diarrhea, headaches and other symptoms. Vitamin C tablet belongs to a kind of medicine, which is used for the prevention of scurvy, and also used for the adjuvant treatment of various acute and chronic infectious diseases and purpura. Long-term use of vitamin C tablets is more likely to cause urate, oxalate stones or cysteinate stones. Secondly, the elderly are also prone to diarrhea, headache, frequent urination, nausea, vomiting, stomach cramps and other adverse reactions. In addition, long-term use of vitamin C tablets may cause scurvy when the drug is suddenly stopped. Therefore, it is not recommended for the elderly to take a vitamin C tablet a day for a long time. Need to take vitamin C tablets for the elderly, must strictly follow the doctor’s instructions, do not take on their own, so as not to adversely affect their health.