What vitamin deficiency causes angular cheilitis?

Angular cheilitis is usually associated with deficiencies in multiple vitamins, mainly including vitamin B2 (riboflavin), vitamin C, and folic acid. Vitamin B2 is an essential nutrient for maintaining the health of the skin and mucous membranes; its deficiency may lead to angular cheilitis, presenting symptoms such as congestion, edema, and erosion of the mucous membrane at the corners of the mouth. Vitamin C, a natural antioxidant, helps promote skin detoxification and repair, and its deficiency may also trigger angular cheilitis. Additionally, a lack of folic acid might increase the risk of developing angular cheilitis. For angular cheilitis, it is recommended to promptly adjust dietary habits and increase the intake of foods rich in vitamins, such as animal liver, fresh vegetables, and fruits. If symptoms are severe, vitamin supplements may be used under a doctor's guidance. Furthermore, maintaining cleanliness and hygiene at the corners of the mouth and avoiding excessive scratching and irritation can also aid in the recovery from angular cheilitis.