Vitamin D in Children With Inflammatory Bowel Disease: A Randomized Controlled Clinical Trial.

BACKGROUND: Vitamin D has anti-inflammatory and immune regulatory functions. GOALS: The authors investigated the effect of vitamin D supplementation in children with inflammatory bowel disease (IBD) and hypovitaminosis D on disease activity, quality of life (QOL), inflammatory markers, and cytokines. STUDY: This randomized double-blinded controlled clinical trial included 120 children with IBD and hypovitaminosis D; 22 of them were excluded later. Patients were randomized to receive either oral vitamin D3 in a dose of 2000 IU/day or placebo for 6 months. The primary outcome was to evaluate the effect of vitamin D supplementation on the IBD activity score. The secondary outcomes were to assess the QOL, inflammatory markers, cytokines, the safety of vitamin D, and to correlate serum vitamin D level with various clinical and laboratory variables. RESULTS: Vitamin D supplementation significantly decreased the IBD activity score in the vitamin D group compared with the placebo group. Moreover, QOL significantly improved after vitamin D supplementation. Inflammatory markers, for example, erythrocyte sedimentation rate, C-reactive protein, and fecal calprotectin and interleukin-2 IL-12, IL-17, IL-23, and tumor necrosis factor-alpha significantly decreased in the vitamin D group. However, IL-10 significantly increased after vitamin D supplementation. Vitamin D was significantly inversely correlated with the activity score, QOL score, levels of all inflammatory markers, the frequency of hospitalization, and emergency department visits. CONCLUSION: Vitamin D supplementation may have a beneficial effect in children with IBD.