Background: The exact aetiology of recurrent aphthous stomatitis (RAS) is still unknown, but different predisposing factors, including iron, vitamin B12 and folic acid deficiencies, have been proposed.
Material and methods: Serum iron, ferritin, folic acid and vitamin B12 levels were investigated in 35 patients with RAS and in 26 healthy controls.
Results: Vitamin B12 levels were found significantly lower in subjects with RAS than in controls. No significant differences were found in other parameters.
Conclusion: We concluded that vitamin B 12 deficiency may be an aetiological factor in recurrent aphthous stomatitis.