Vitamin D Level and Supplementation in Pediatric Atopic Dermatitis: A Randomized Controlled Trial

Children and adolescents with atopic dermatitis were evaluated at a dermatology clinic in Toronto, Canada. Participants with insufficient or deficient vitamin D levels entered a phase 2 double-blind randomized controlled trial; 21 were randomized to vitamin D supplementation and 24 to placebo.

Vitamin D supplementation was given as 2 drops daily, with each drop containing 1000 IU, for 3 months. The active regimen was compared with placebo in a double-blind randomized trial.

Vitamin D supplementation increased serum vitamin D levels but did not significantly improve atopic dermatitis severity versus placebo. In the vitamin D group, mean serum vitamin D rose from 47.1 (15.2) nmol/L at baseline to 81.5 (23.2) nmol/L at the end of treatment, while SCORAD improved from 27.3 (17.8) to 15.4 (9.7). However, SCORAD change was similar between groups: 15.4 (9.7) in the vitamin D group versus 15.3 (9.0) in the placebo group, with p = .7. No adverse effects were observed.

The active vitamin D arm was small, with only 21 randomized and fewer analyzed for some outcomes, limiting power to detect clinical benefit. Treatment lasted only 3 months, and the optimal vitamin D dosing regimen remains unclear. The trial was conducted in a single center in Toronto, which may limit generalizability.