AimsTo investigate levels of 25-hydroxyvitamin-D (25HVD), interleukin-17 (IL-17), IL-27, IL-35, and transforming growth factor β1 (TGF-β1) in chronic spontaneous urticaria (CSU) patients and their correlations with disease activity.MethodsAn observational, case-control study was conducted. Eighty-one CSU patients and fifty-eight healthy individuals were recruited into two groups. Serum levels of 25HVD, IL-17, IL-27, IL-35, TGF-β1 were determined via enzyme-linked immunosorbent assay (ELISA). Disease activity of CSU was assessed using urticaria activity score (UAS).ResultsSerum level of 25HVD was significantly lower in CSU group compared to control group (P < 0.001). Serum levels of IL-17 (P < 0.001), IL-27 (P < 0.001), TGF-β1 (P = 0.01) were significantly higher in CSU group than those in control group. In CSU group, the level of 25HVD was negatively associated with IgE (P < 0.01) and positively correlated with IL-35 (P < 0.01). In addition, serum level of IL-17 was negatively correlated with disease activity among female patients (P < 0.05).ConclusionDeficiency of 25HVD is associated with development of CSU, the underlying mechanism might be related with IL-35. Likewise, IL-17, IL-27, IL-35, and TGF-β1 might also contribute to development of CSU.