Patients with oral ulcers should analyze the cause of the ulcers to determine what vitamins to take. If the ulcers are caused by a vitamin deficiency, oral intake of some B vitamins, such as B1, B2, B6, B12, or some complex B vitamins, can be beneficial. However, if the ulcers are due to other reasons, supplementing with B vitamins does not yield particularly good results. It is recommended that patients use local treatments such as watermelon frost or boric acid powder to promote the healing of ulcers. If the pain is severe, local use of lidocaine gel can be applied for pain relief. In daily life, it is advisable to consume fresh fruits and vegetables and avoid spicy, stimulating, and overly greasy foods.