Table 4.

Unanswered clinical questions regarding the role of vitamin D in inflammatory bowel diseases

Does low serum vitamin D cause Crohn’s disease or ulcerative colitis, or is it a marker for other risk factors? Can supplementation with vitamin D in high-risk individuals prevent or delay the onset of Crohn’s disease or ulcerative colitis? Does vitamin D deficiency cause a more severe phenotype or increased inflammatory activity in Crohn’s disease, or is it merely a consequence of severity of disease? Is vitamin D status predictive of recurrence of Crohn’s disease post-operatively? What is the role of vitamin D Can supplementation with vitamin D in patients with IBD? Induction of remission? Maintenance of remission and prevention of relapse? Prevention of post-operative recurrence? What is the optimal serum 25(OH)D level for its effect on inflammation in patients with IBD? What is the optimal dose and modality for treatment of vitamin D deficiency in IBD patients? Can vitamin D supplementation reduce risk of colorectal cancer in IBD?