Recurrent aphthous ulcers (RAUs), also called recurrent aphthous stomatitis (RAS), are commonly known as canker sores. They are among the most frequent lesions affecting the oral mucosa. From a conventional medical perspective, the exact cause of canker sores is often described as unknown. However, a number of studies suggest that nutritional factors may play a role in at least some patients.
Research published in the Journal of the European Academy of Dermatology and Venereology (2002;16(1):66–67) examined iron, ferritin, folic acid, and vitamin B12 levels in 35 patients with recurrent aphthous stomatitis. The researchers found that vitamin B12 levels were significantly lower in the RAS group compared to healthy control subjects. Similar findings were reported in the Netherlands Journal of Medicine (1998;53(4):172–175), which also noted an association between low vitamin B12 levels and recurrent oral ulcers.
Additional research supports the idea that other nutrient deficiencies may be involved. A study published in the Journal of Oral Pathology (1983;12(4):290–299) found a relationship between low ferritin levels and oral ulcerations. Earlier work published in the British Medical Journal (1975;2(5969):490–493) suggested that deficiencies in iron, folic acid, and vitamin B12 were more common in patients with recurrent oral ulcers. Importantly, patients in these studies often showed improvement when the identified deficiencies were corrected.
Taken together, these findings suggest that while canker sores may have multiple contributing factors, nutritional status—particularly iron, folate, and vitamin B12 levels—deserves consideration in patients with recurrent aphthous ulcers.
