In general, the elderly can take vitamin C tablets under the guidance of a doctor when there are indications. Vitamin C is used for the prevention of scurvy, and can also be used in the adjuvant treatment of various acute and chronic infectious diseases and purpura. Vitamin C contraindications have not been clear, but when taking vitamin C should not be taken for a long time overdose, otherwise sudden withdrawal of the drug may appear scurvy symptoms. Vitamin C can pass through the placenta and be secreted into breast milk, and when pregnant women take too much, it can induce scurvy in newborns, so special attention should be paid. The following conditions should be used with caution: cysteinuria, gout, hyperoxaluria, oxalate deposition, urate kidney stones, glucose-6-phosphate dehydrogenase deficiency, hemochromatosis, ferrocytic anemia or thalassemia, sickle cell anemia, diabetes mellitus (due to vitamin C interferes with blood glucose quantification). Note that vitamin C for the elderly should be consumed correctly and in accordance with medical advice.