Vitamin C has side effects, including the development of gastrointestinal disorders, such as excessive secretion of stomach acid, gastric ulcers, gastritis or other symptoms such as bloating, diarrhea, vomiting, etc. Long-term abdominal pain, diarrhea and vomiting can lead to hypokalemia in patients. In addition, overdose of vitamin C can also lead to increased blood viscosity, causing patients to develop blood clots, which can block blood vessels and cause cardiovascular disease in serious cases. It can also lead to hemolysis, reduced phagocytosis of white blood cells in the body, low autoimmunity, and even autoimmune system diseases. In severe cases, it can lead to blood clotting or hemolysis, muscle weakness, fatigue, mental slackness and a series of other symptoms, affecting the pumping ability of the heart and leading to hypotension and anemia.