A case-control study: evaluation of vitamin D metabolism in patients with vitiligo.

BACKGROUND/AIM Reduced vitamin D is considered as one of the environmental factors that can increase the prevalence of certain autoimmune diseases. This study aimed to assess vitamin D metabolism in patients with vitiligo. MATERIALS AND METHODS A prospective case-control study was conducted on 44 consecutive patients with vitiligo vulgaris and 43 healthy controls. Their plasma 25-hydroxyvitamin D (25(OH)D), parathormone (PTH), calcium, magnesium, and phosphate levels were measured. RESULTS There was no significant difference in the mean age, sex and Fitzpatrick skin phototype between the patient and control groups (P > 0.05). The plasma levels of 25(OH)D and calcium were significantly decreased (P = 0.002, P < 0.0001, respectively) and PTH and magnesium levels were significantly increased in patients with vitiligo (P < 0.0001, P < 0.0001, respectively). The advancement of age (P = 0.03, R = -0.18) and comorbid autoimmune illnesses (P = 0.04) were found to be significantly associated with lower 25(OH)D levels. CONCLUSION There is a universal lack of 25(OH)D in the Turkish population. Screening for vitamin D may be a tool for the presence of comorbid autoimmune diseases. Further studies are needed to understand the role of vitamin D metabolism in the pathogenesis of vitiligo.