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

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.