Vitamin D is traditionally associated with bone metabolism.
The immunological effects of vitamin D have increasingly come into focus.
Dr Ananthakrishnan and colleagues from Massachussetts, USA reviewed the evidence supporting a role of vitamin D in inflammatory bowel diseases.
The research team performed a comprehensive search on PubMed using the terms ‘crohn's disease’ ‘ulcerative colitis’ and ‘vitamin D’.
Vitamin D deficiency is common in patients with inflammatory bowel diseases (IBD) including those with recently diagnosed disease.
Evidence supports immunological role of vitamin D in IBD.
|Vitamin D deficiency was associated with increased risk of surgery in CD|
|Alimentary Pharmacology & Therapeutics|
In animal models, deficiency of vitamin D increases susceptibility to dextran sodium sulphate colitis, while 1,25(OH)2D3 ameliorates such colitis.
The team identified 1 prospective cohort study that found low predicted vitamin D levels to be associated with an increased risk of Crohn's disease (CD).
Limited data also suggest an association between low vitamin D levels and increased disease activity, particularly in CD.
In a large cohort, the team oberved that vitamin D deficiency was associated with increased risk of surgery in CD, and hospitalizations in both CD and UC.
A single randomized controlled trial demonstrated that vitamin D supplementation may be associated with reduced frequency of relapses in patients with CD compared with placebo.
Dr Ananthakrishnan's team concludes, "There is growing epidemiological evidence to suggest a role for vitamin D deficiency in the development of IBD, and also its influence on disease severity."
"The possible therapeutic role of vitamin D in patients with IBD merits continued investigation."