Effects of Vitamin D Supplementation on Intestinal Inflammation in Experimental Inflammatory Bowel Disease

Vitamin D may have immunomodulatory effects in the intestine. Our objective was to determine if exposure to vitamin D mitigates intestinal inflammation in IL-10 KO mice. Mice were randomized to a diet containing 25 IU (low) or 5000 IU (high) of vitamin D/kg of diet in utero and offspring were maintained on the same diet or switched to the other diet at weaning. Fecal samples were collected at 3 months of age. Vitamin D did not affect intestinal inflammation in male and female mice and did not affect KC cytokine concentration or regulate colonic gene expression in male mice. Vitamin D modulated the gut microbiota in a sex-specific manner and depending on timing of exposure. Females in the HH group had significantly higher fecal counts of C. coccoides than the other vitamin D interventions. Therefore, vitamin D may favourably modulate microbiota composition without attenuating inflammation.MAS