Alopecia areata is a chronic relapsing autoimmune inflammatory hair disorder with no novel therapy. The objectives of this study are to compare the efficacy of topical calcipotriol vs narrow band ultraviolet B phototherapy (NB-UVB) in the treatment of alopecia areata and its correlation with serum vitamin D₃ levels. A randomized-controlled trial has been conducted on 60 patients with scalp alopecia areata randomized into four groups; topical calcipotriol, NB-UVB, both and placebo. All patients were evaluated by assessment of severity of alopecia areata by severity of alopecia tool (SALT) score at baseline and 3 months after treatment and vitamin D₃ levels at baseline and after 3 months. SALT score and vitamin D₃ levels were significantly improved in all groups except placebo after treatment with (P = 0.026, P = 0.005, P = 0.004, P = 0.140) and (P = 0.028, P = 0.011, P = 0.003, P = 0.725 …