Vitamin D deficiency is believed to be a risk factor for Recurrent Aphthous Stomatitis (RAS). Although at this time, RAS causes are still unknown, several studies mention the risk factors that can cause RAS, including genetic, stress, anemia, nutritional or vitamin deficiency, hormonal imbalance, and recurring local trauma. RAS is canker sores or lesions that are often found in patients' oral cavity, especially in patients who live in the 1-4 decades of life, or ages 1-40 years. The frequency of the emergence of RAS will decrease over 40 years.

Deficiency of Vitamin D Causes Recurrent Aphthous Stomatitis (RAS)
Aphthous Stomatitis

Recurrent Aphthous Stomatitis Risk Factors 

In adults, 25% of ulcers that often occur in the oral cavity are RAS. Meanwhile, in children, up to 40% of the ulcers in the oral cavity that often occur are RAS. The most common symptoms of RAS are burning and pain in the ulcer area. There are three subtypes of RAS severity, namely: minor, major, and herpetiform.

Until now, the etiopathogenesis of RAS is still unknown with certainty. Local trauma, genetic factors, stress, food allergies, immunological disorders, nutritional deficiencies, viral, bacterial or fungal infections, and endocrine disorders are often associated with risk factors. However, the pathophysiology of how each of these risk factors contributes to RAS is not well explained. 

Nutritional (such as vitamin B1, B2, B6, B12, vitamin C, and iron) deficiencies are the most frequently discussed risk factors for RAS because several previous studies indicated a decrease in these nutrients is correlated with an increase of RAS incidence in a person.

Since 2015, a new hypothesis has emerged that vitamin D deficiency is a risk factor for RAS. Vitamin D deficiency is associated with various systemic disorders: such as cancer, musculoskeletal disorders, cardiovascular disorders, depression, and various autoimmune diseases (such as lupus erythematosus). Because of vitamin D's potential against various diseases, especially autoimmune, making the discussion about vitamin deficiency is often raised in the medical literature. The world of dentistry is no exception, which has started trying to find out whether there is a link between vitamin D deficiency and the incidence of RAS.

Correlation between Vitamin D Deficiency and Recurrent Aphthous Stomatitis

Vitamin D is a fat-soluble secosteroid and plays a fundamental role in calcium-phosphorus homeostasis and bone metabolism. Vitamin D also has an important biological role in carrying out skeletal functions, regulating immune responses, controlling infection, and malignancy. The association between vitamin D deficiency and RAS was first reported by Khabbazi et al. in 2015. In that study, most RAS sufferers had low vitamin D levels. However, there is still some controversy over whether vitamin D can be categorized as a RAS risk factor or not.

Several researchers have suggested that immunological mechanisms (both cellular and humoral) play important roles in RAS's pathogenesis. 

Cytokines involved in the inflammatory response can also mediate the immune response and may be linked to RAS formation. This immunological mechanism is the common thread that connects vitamin D deficiency with RAS. Because vitamin D has an important role in regulating the immune system (both congenital and acquired) and affects the cytokine profile, this may be an indirect link between vitamin D deficiency and the incidence of RAS.

Several studies regarding vitamin D deficiency and RAS mentioned that patients with RAS disease have low of vitamin D levels in their bodies. However, qualitative analysis in each of these studies found no significance between vitamin D deficiency and the severity of RAS, such as duration, frequency, diameter, or RAS healing time.

Vitamin D deficiency may be categorized as a risk factor for RAS because the results of previous studies support this. However, as with other risk factors for RAS, the etiopathogenesis of vitamin D against RAS remains uncertain. However, further research is needed to guide RAS therapy with vitamin D supplementation.