Aphthous ulcers and vitamin B12 deficiency.

Aphthous ulcers of the oral cavity are frequently encountered in general practice. Although the exact pathophysiology remains obscure, many factors can contribute to the pathogenesis of these lesions, such as immunological factors, local trauma, smoking, stress, hormonal state, family history, food hypersensitivity, and infection. We describe three patients in whom a clear relationship appeared to exist between recurrent aphthous ulcers and a deficiency of vitamin B12. It is concluded that in all patients with recurrent aphthous ulceration, deficiency of vitamin B12 should be considered.