Vitamin B2 is recommended to be taken in moderation, and when used in the treatment of some diseases, it can be discontinued if the symptoms disappear or are significantly reduced, and replaced by obtaining vitamin B2 from the daily diet; overdosage may bring about a number of adverse effects, as explained below: Vitamin B2, also known as riboflavin, is an important part of the flavoprotein cofactor in the body. When vitamin B2 is deficient, it affects the oxidation of the body and leads to metabolic disorders. The main clinical manifestations are inflammation of the mouth, eyes, and external genitalia, such as labial inflammation, corneal inflammation, lingual inflammation, conjunctivitis, and scrotal inflammation, etc. Vitamin B2 can be used in the prevention and treatment of the above diseases. Stop taking it if the symptoms disappear or are significantly reduced when used to treat diseases such as xerostomia, keratitis, ligamentitis, and conjunctivitis. Excessive intake may cause itching, paralysis, nosebleeds, burning sensation and tingling. If you are taking anticancer drugs such as methotrexate, excessive amounts of B2 may reduce the effectiveness of these anticancer agents.