Serum level of vitamin D3 in vitiligo patients before and after treatment with narrow band UVB. Is there an association with treatment?

Vitiligo is a pigmentation disorder of the skin characterized by the loss of melanocytes through different mechanisms. Narrow band UVB (NBUVB) is a safe and effective treatment for vitiligo that acts by inducing the synthesis of cytokines involved in melanogenesis. NBUVB appears to be involved in the treatment of vitiligo by increasing the synthesis of vitamin D, which prevents the apoptosis of melanocytes; accordingly, we set out to compare the serum level of vitamin D and its variations following NBUVB treatment according to the degree of response to treatment. Thirty-eight patients with vitiligo were subject to phototherapy with NBUVB. Photographs of vitiligo lesions were taken prior to and after completing 60 phototherapy sessions. Further measured were the serum level of 25-hydroxyvitamin D3, VASI score and repigmentation rate before and after the treatment period. Finally, the relationship between the changes in serum vit D3 levels and variations of VASI score was investigated. Mean serum level of vitamin D3 was 20.78 ng/ml after treatment, which is significantly more compared to the period before the treatment (15.42, P=0.001). Mean VASI score was 5.45 before the treatment, yet was reduced to 2.24 after treatment, which is a significant change (P<0.001); however, the changes in vitamin D3 levels were not significantly correlated with VASI score (P=0.137). The repigmentation rate in vitiligo lesions are not significantly correlated with serum vitamin D3 levels. Therefore, NBUVB is not likely to improve vitiligo lesions through the increase in serum vitamin D levels.