Mouth ulcers among the pathogenic factors is the lack of trace elements and vitamins, especially vitamin B, vitamin C deficiency, so when you choose to eat, you can eat fruits rich in vitamins, you can choose the fruits include: i. Apple, apple is rich in vitamin B and C, suitable for the treatment of mouth ulcers. Two, pear, pear is rich in vitamin B, is more suitable for mouth ulcers fruit. Three, persimmon, persimmon can also be effective in preventing mouth ulcers, especially persimmon cream, take persimmon cream from persimmon cake, take it with boiling water or add it to porridge, it has good effect. Also eat less acidic foods, such as citrus, tomatoes or nuts. Eat less overly spicy or salty food, avoid hard, too hot food, no smoking and drink less alcohol to prevent mouth ulcers.