The correlation analysis between alterations of serum vitamin D, IL‐33 levels, and clinical improvement after narrow‐band UVB treatment in vitiligo patients: A case–control study

Abstract Background The etiology of vitiligo has not been completely elucidated. Recently, 25‐hydroxyvitamin D (25(OH)D) and IL‐33 levels were found to be associated with the development of the vitiligo. The aim was to assess relationship between 25(OH)D, IL‐33 levels, and clinical improvement after narrow‐band UVB treatment in vitiligo. Method Patients with vitiligo who underwent at least 48 sessions of narrow‐band UVB treatment were included in this study. Age, gender, smoking status, family history of vitiligo, type of vitiligo, body surface area affected by vitiligo, and vitiligo activity were recorded. 25(OH)D and IL‐33 were measured and compared at baseline, second month, and fourth month. Results Twenty patients with vitiligo and 20 healthy controls were included in this study. The mean baseline 25(OH)D level of vitiligo group was statistically significantly lower than the control group's ( p < .05). The mean baseline IL‐33 level was higher in vitiligo group with no statistically significantly difference ( p > .05). The increase in 25(OH)D level and the decrease in vitiligo‐affected body surface area were found to be statistically significant during treatment ( p < .05). The mean IL‐33 levels were found to be lower at the second and fourth month compared to baseline. However, there were no statistical significance ( p > .05). Conclusion Low levels of 25(OH)D are thought to play a role in the etiopathogenesis of vitiligo. 25(OH)D increase due to phototherapy may have a role in repigmentation independently from the direct effect of narrow‐band UVB.