Fig. 1
From: Relationship between vitamin D and chronic spontaneous urticaria: a systematic review
Flow diagram of literature review in this study. Seventeen studies met the inclusion criteria and were included in our systematic review. *Of the 14 studies, the relation between serum vitamin D level and CSU were assessed [14, 18, 20,21,22,23,24,25, 28,29,30,31,32,33]. †In 7 studies, various severity assessment were used to evaluate the effect of vitamin D supplementation in CSU patients [19, 24,25,26,27, 31, 32]. CSU chronic spontaneous urticaria