Vitamin B2 (riboflavin) is a component of flavin adenine dinucleotide (FAD), an important phosphorus-containing compound in the body, which is an intracellular redox coenzyme involved in important metabolic reactions. It is widely involved in various redox reactions in the body, and can promote the metabolism of sugar, fat and protein. At the same time, FAD, as a vitamin B2 derivative, has a role in maintaining the normal function of skin, mucous membrane and vision. Vitamin B2 is not only a component of the FAD molecule, but also a functional site of FAD, which is converted into FADH2 by getting two electrons, thus realizing the role of electron transfer. The electron-binding site is vitamin B2. Vitamin B2 deficiency affects the electron-transferring role of FAD, which causes metabolic disorders that first affect the mucous membranes and skin. Typical manifestations are inflammation of the mucous membranes of the mouth and lips and the oral cavity, such as stomatitis, labial inflammation, tongue inflammation, “map tongue”, gingivitis, oral ulcers, etc. Sometimes it also manifests as inflammation around the genitals, such as scrotal inflammation, glansitis, inguinal inflammation, etc. Eye symptoms are also common, such as photophobia, tearing, dryness and itching of the eyelids. It may also be accompanied by systemic symptoms, such as fatigue and weakness. Vitamin B2 is widely distributed in vegetables, legumes, fish, eggs and milk, and other animal foods. However, if you try to find out a certain food rich in vitamin B2 and consume sufficient B2 by eating more of it, you will surely be disappointed. This is because vitamin B2 is not found in a lot of various foods. In this way, a balanced and well-matched diet must be consumed in order to get sufficient B2. It is easy to be deficient in B2 whenever you have not had a balanced diet for a period of time (not enough fresh vegetables or not enough meat, eggs and milk.) It is easy to understand that vitamin B2 deficiency is very common and almost the vast majority of people have had it at one time or another, with “fire”, stomatitis and mouth ulcers being very common problems. Vitamin B2 deficiency often occurs in conjunction with other nutrient deficiencies. Vitamin B2 deficiency is often the result of an unbalanced diet, and an unbalanced diet is likely to be deficient not only in B2, but also in other nutrients, such as vitamin C deficiency, zinc deficiency, B1 deficiency, etc. This phenomenon gives us two important tips: 1. Vitamin B2 deficiency can often be an indicator of poor recipes. Once a B2 deficiency occurs, it means that your recipe is faulty and is likely to be deficient in several nutrients. 2. When supplementing with vitamin B2, it is also important to take a combination of other vitamins and minerals. Or consume a fundamentally paired and balanced diet. In addition, because it is difficult to find several natural foods rich in vitamin B2 and sufficient to solve B2 deficiency, when B2 deficiency symptoms such as “fire”, corns and mouth ulcers appear, you should immediately take supplements containing vitamin B2, other B vitamins, VC, VE, zinc, iron and other multi-nutrients. supplements (health food) or drugs (OTC) containing vitamin B2, other B vitamins, VC, VE, zinc, iron and other nutrients, of which vitamin B2 should be taken in larger doses of 10-20 mg daily. In practice, the effect of vitamin B2 supplementation alone is often inferior to that of a combination of multiple nutrients. This is because deficiencies of other nutrients can also lead to oral symptoms. Vitamin B1 deficiency can lead to oral mucosa allergy, tongue pain, swollen gums, etc.; vitamin B6 deficiency can lead to oral ulcers and promote stomatitis and gingivitis; vitamin B5 (niacin) deficiency can easily lead to stomatitis, gingivitis and tongue inflammation; vitamin C deficiency can easily lead to gum redness, swelling, erosion, bleeding and bad breath in the mouth; vitamin E deficiency can lead to periodontal disease, mucosal disease etc. Zinc deficiency makes mouth ulcers not easy to heal, etc.