You may want to have allergy tests done or test yourself by eliminating the suspected foods from your diet for a few weeks, then reintroduce them one at a time and see which one triggers a canker. Cutting out sugar, coffee, and spicy or salty foods, may help as well. Even without celiac disease, however, a person who is prone to canker sores may be more sensitive to gluten. Having too much acidity in your stomach has been reported as a possible cause. If your body is too acidic and you have to take antacids regularly.
Nutritional deficiencies are another possible cause.
We suggest taking a good multi-vitamin and making sure you have a good diet as part of your program to overcome canker sores. Adding beta-carotene to your diet will speed the healing of the mucous membranes in your mouth. Call your healthcare provider if the cankers develop after starting medication, last more than two weeks, or if white spots that are not canker sores appear in the mouth and are not improving in one or two weeks. Also see your doctor if you have a painless ulcer in your mouth that doesn't go away as it may be the symptom of a more serious underlying medical condition. The main cornerstone of your Wellness Program will be to make dietary modifications.