Comparison of Vitamin D Levels in Patients with and without Acne: A Case-Control Study Combined with a Randomized Controlled Trial

Background Vitamin D plays an important role in the immune system, and its deficiency has been implicated in various skin diseases, including atopic dermatitis and psoriasis. Acne is a common inflammatory skin disease; however, the association with vitamin D remains unclear. Objectives We evaluated vitamin D levels in patients with acne to determine the effect of vitamin D supplementation. Methods This study included 80 patients with acne and 80 healthy controls. Serum 25-hydroxyvitamin D (25(OH) D) levels were measured, and demographic data were collected. Vitamin D-deficient patients were treated with oral cholecalciferol at 1000 IU/day for 2 months. Results Deficiency in 25(OH) D was detected in 48.8% of patients with acne, but in only 22.5% of the healthy controls. The level of 25(OH) D was inversely associated with the severity of acne, and there was a significant negative correlation with inflammatory lesions. In a subsequent trial, improvement in inflammatory lesions was noted after supplementation with vitamin D in 39 acne patients with 25(OH) D deficiency. Limitations Limitations of the study include the small number of patients in the supplementation study and the natural fluctuation of acne. Conclusions Vitamin D deficiency was more frequent in patients with acne, and serum 25(OH) D levels were inversely correlated with acne severity, especially in patients with inflammatory lesions.