Evidence for vitamin D deficiency and increased prevalence of fractures in autoimmune bullous skin diseases

Background. Vitamin D deficiency plays a role in autoimmune diseases and risk of fractures. No data are available on vitamin D levels and vertebral fractures in autoimmune bullous skin diseases. Objectives  To assess vitamin D serum levels and vertebral fractures' prevalence in patients with pemphigus vulgaris (PV) and bullous pemphigoid (BP), potentially fatal autoimmune bullous disorders,. Methods  We studied 13 consecutive active untreated inpatients with PV (6 males, 7 females, age 53.5 ± 14.3 years), 15 with BP (7 males, 8 females, age 76.9 ± 12.4 years) and 28 age- body mass index- and sex- matched controls. In all subjects, the 25(OH)Vitamin D (25OHD) levels and presence of vertebral fractures by spinal radiographs were assessed. Results  In PV patients, 25OHD levels were lower (12 ± 4.4 ng/mL) and prevalence of severe hypovitaminosis D higher (61.5%) than in controls (22.2 ± 11.7 ng/mL, p=0.012; 23.1%, p=0.0047, respectively). The prevalences of fractures were 53.8% and 30.8% in PV patients and controls, respectively. Patients with BP showed lower 25OHD levels (9.6 ± 7.2 ng/mL) and higher prevalence of severe hypovitaminosis D (73.3%) than controls (22.6 ± 18.7 ng/mL, p=0.022; 26.7%, p=0.01, respectively). The prevalences of fractures tended to be higher in BP patients than in controls (66.7% vs 33.3%, respectively, p=0.068). Conclusions  The low 25OHD levels found in PV and BP may suggest a role for this agent in their pathogenesis. The increased prevalence of fractures should be taken into consideration in patients who must be given corticosteroid.