Effect of narrow‐band ultraviolet B on the serum of 25‐hydroxyvitamin D in vitiligo patients

Summary Background Narrow‐band ultraviolet B ( NB ‐ UVB ) is the gold standard in the treatment of vitiligo. 25‐hydroxyvitamin D (25‐ OH ‐ vitamin D) might play a physiological role in photo‐induced melanogenesis in human skin so the association between vitamin D levels and vitiligo still needs to be investigated more thoroughly. Objective we aim to investigate the influence of cumulative doses of NB ‐ UVB phototherapy on vitamin D in patients with vitiligo and their correlation with NB ‐ UVB ‐induced pigmentation. Methods Eighty patients of vitiligo and twenty number of age and sex matched controls were recruited in a case‐control study. Patients with vitiligo were treated with NB ‐ UVB twice weekly for 24 weeks. 25‐hydroxy vitamin D levels were measured at 0, 12, and 24 weeks in the cases and at 0 only in control by enzyme‐linked immunosorbent assay ( ELISA ) and Vitiligo Area Severity Index ( VASI ) were calculated at 0 (baseline) and 24 weeks. Results The mean baseline level of 25‐hydroxyvitamin D (at 0 week) was significantly lower in patients than the control group. Levels of 25( OH ) vitamin D at 12 and 24 weeks showed significant improvement and Patients show significant reduction in VASI score after 24 weeks of therapy. Conclusions Cumulative doses of NB ‐ UVB therapy improve low vitamin D levels in patients with vitiligo, which might have a significant role in NB ‐ UVB ‐induced repigmentation and may contribute to its therapeutic efficacy but further studies with larger sample size are needed to prove the complete mechanisms of NB ‐ UVB ‐induced pigmentations and vitamin D in vitiligo.