Vitamin D supplements improve urticaria symptoms and quality of life in chronic spontaneous urticaria patients: A prospective case-control study.

Vitamin D plays an important role in the immune system; decreased serum vitamin D concentrations have been linked to dysregulated immune function. Low vitamin D status is probably associated with chronic spontaneous urticaria (CSU). We evaluated the prevalence of low vitamin D status, and the clinical response and quality of life following vitamin D supplementation, in a prospective case-control study with 60 CSU patients and 40 healthy individuals. Serum 25-hydroxy vitamin D (25(OH)D) concentrations were measured at baseline and after 6 weeks. For patients with 25(OH)D concentrations < 30 ng/ml, treatment included 20,000 IU/day of ergocalciferol (vitamin D2) and non-sedative antihistamine drugs for 6 weeks. Urticaria symptom severity and quality of life were assessed based on the Urticaria Activity Score over 7 days (UAS7) and the Dermatology Life Quality Index (DLQI). Of the 100 participants, 73% were female; the mean age was 39 ± 16 years. Vitamin D deficiency (measured as 25(OH)D < 20 ng/ml) was significantly higher in the CSU group than the control group. The median 25(OH)D concentration for the CSU group, 15 (7 - 52) ng/ml was significantly lower than for control group, 30 (25 - 46) ng/ml. Overall, 83% (50/60) of CSU patients (25(OH)D < 30 ng/ml) were treated with ergocalciferol (vitamin D2) supplementation; after 6 weeks, these patients showed significant improvements in UAS7 and DLQI scores compared with the non-vitamin D supplement group. This study revealed a significant association of lower serum 25(OH)D concentrations with CSU. Vitamin D supplements might improve symptoms and quality of life in CSU patients.