Researchers conducted a double-blind randomized placebo-controlled study, assigning 27 Crohn’s disease (CD) patients in remission to 2000 IU/day of vitamin D3 or placebo for 3 months. They determined intestinal permeability (IP), plasma-cathelicidin (LL-37), human-beta-defensin-2 (hBD2), disease activity [Crohn’s Disease Activity Index (CDAI)], c-reactive protein (CRP), fecal calprotectin, Quality of Life (QoL) and serum vitamin d (25(OH)D) at 0 and 3 months. Results showed that at 3 months, 25(OH)D concentrations were significantly higher in the treated group, and intra-group analysis showed increased LL-37 [an antimicrobial peptide (AMP) of the innate immune system expressed by the gastrointestinal epithelium] concentrations, and maintenance of IP measures. In contrast, in the placebo group, the small bowel and gastro-duodenal permeability increased from baseline. At 3 months, patients with 25(HO)D levels > 75 nmol/L had significantly lower CRP, higher QoL, higher LL-37 concentrations and lower CDAI scores compared to those with lower 25(OH)D levels.
T Raftery, et al. Effects of vitamin D supplementation on intestinal permeability, cathelicidin and disease markers in Crohn’s disease: Results from a randomized double-blind placebo-controlled study. United Euro Gastro Journal 2015, Vol. 3(3) 294-302