1,25-dihydroxycholecalciferol prevents and ameliorates symptoms of experimental murine inflammatory bowel disease

Anecdotal data suggest that the amount of vitamin D available in the environment either from sunshine exposure or diet may be an important factor affecting the development of inflammatory bowel disease (IBD) in humans. We tested the vitamin D hypothesis in an experimental animal model of IBD, Interleukin (IL)-10 knockout (KO) mice, which spontaneously develop symptoms resembling human IBD, were made vitamin D deficient, Vitamin D sufficient or supplemented with active vitamin D (1,25-dihydroxycholecalciferol). Vitamin D-deficient IL-10 KO mice rapidly developed diarrhea and a wasting disease, which induced mortality. In contrast, vitamin D-sufficient IL-10 KO mice did not develop diarrhea, waste or die. Supplementation with 50 IU of cholecalciferol (5.0 mug/d) or 1,25-dihydroxycholecalciferol (0.005 mug/d) significantly (P < 0.05) ameliorated symptoms of IBD in IL-10 KO mice. 1,25-Dihydroxycholecalciferol treatment (0.2 <mu>g/d) for as little as 2 wk blocked the progression and ameliorated (P < 0.05) symptoms in IL-10 KO mice with already established IBD.