Effect of Vitamin D Supplementation on Inflammatory Bowel Disease in Children: A Meta-Analysis

Abstract

Background: Apart from its role in bone health, recent developments have shown that vitamin D also has anti-inflammatory properties, and therefore may have a role in inflammatory bowel disease (IBD) in children. Objectives: To determine the effect of vitamin D supplementation on the disease activity of pediatric patients with IBD. Design: Random-effects meta-analysis Data Sources: Studies were searched at Cochrane Library, PubMed, EBSCO Host, ScienceDirect, Google Scholar, and Wiley Online. Review Methods: Experimental studies measuring the effect of vitamin D on the disease activity of pediatric patients with IBD were included. The proportion of disease activity, measured as remission rate or inactivity using Pediatric Crohn’s Disease Activity Index (PCDAI) or Pediatric Ulcerative Colitis Activity Index (PUCAI), and the mean and standard deviation of mean serum vitamin D [25(OH)D] level, change in 25(OH)D, and different inflammatory markers [erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)] were extracted or estimated and recorded in an abstraction form. Standardized mean difference and odds ratio were used as summary effect measures and estimated using Stata/Multiprocessor. Results: The serum 25(OH)D (SMD = 1.75, z = 2.33, p = 0.001) and change in 25(OH)D (SMD = 3.37, z = 2.34, p = 0.019) was significantly higher among those who received a high dose of vitamin D. However, a significantly high heterogeneity was estimated (I2 >50%). For the disease activity of IBD, the standard mean difference of mean ESR (SMD = –1.10, z = 5.35, p = 0.001) was significantly lower with high-dose vitamin D. The likelihood of remission rate using the Pediatric Crohn’s Disease Activity Index (PCDAI) or Pediatric Ulcerative Colitis Activity Index (PUCAI), and standardized mean difference of CRP were not significantly different among those who received high-dose and low-dose vitamin D. Conclusion: Cognizant of the functions of vitamin D in enhancing intestinal flora balance, regulating immunologic response, and improving intestinal mucosal barrier, vitamin D can be recommended as a supplementary treatment for IBD among the pediatric population. Nevertheless, there is still insufficient evidence for the cut-off level of adequate levels of serum 25(OH)D among pediatric patients with IBD, thus necessitating further studies. Key words: Vitamin D therapy, Pediatric Inflammatory Bowel Disease, Vitamin D deficiency