A good place to start is by seeing your doctor and having her take blood tests to measure your levels of B vitamins, folate, and other minerals. If you are deficient in any of these, your doctor can suggest appropriate supplements (It is not a good idea to take an excess of vitamins or minerals as toxicities can occur when you take too many).

Other readers have reported that a daily supplement of the amino acid lysine has dramatically reduced their occurences of canker sores. Please consult your physician for an appropriate daily dosage.