RESUMEN
AIM: Vitamin D plays an important role in immune system regulation, also its deficiency is assumed to affect the patients' predisposition to viral diseases such as recurrent herpes labialis. In this cross-sectional study, we tried to compare the mean serum level of vitamin D in participants with a positive history of recurrent herpes labial lesions and healthy controls. MATERIALS AND METHODS: The vitamin D serum level of 43 participants with a positive history of recurrent herpes labial lesions who were referred to the Motahhari laboratory in Shiraz during 2020-2022, was compared with 42 healthy controls. It was assessed by an Elisa kit. An Independent T-test was used to compare the vitamin D serum level between two genders. In order to assess the mean age value and gender distribution, an independent T-test and Pearson Chi-Square were used, respectively for the two groups. The serum vitamin D level was compared between both control and test groups. RESULTS: There was no significant difference between vitamin D mean serum levels in the two evaluated groups (p.value = 0.72). Although the age (p.value = 0.09) and recurrence (p.value = 0.13) of herpes labialis had no statistically significant relation to the vitamin D serum level, the healing duration of herpes labialis was inversely related (p.value = 0.01). Lower-level of serum vitamin D were accompanied by a longer healing duration of the lesions. CONCLUSION: Although the vitamin D serum level of participants with a history of recurrent herpes labialis had no relation with age and herpes virus recurrence frequency, a longer healing duration of lesions had been reported in patients with lower serum levels of vitamin D.