Vitamin D in Inflammatory Bowel Diseases. Mechanisms of Action and Therapeutic Implications

Nutrients. 2022 Jan 9;14(2):269. doi: 10.3390/nu14020269.


(1) Background: Vitamin D is an immunoregulatory factor influencing intestinal homeostasis. Recent evidence supports a central role of this micronutrient in the course of Inflammatory Bowel Diseases (IBD). This narrative review aims to provide a general overview of the possible biological mechanisms of action of vitamin D and its therapeutic implications in IBD. (2) Methods: A systematic electronic search of the English literature up to October 2021 was performed using Medline and the Cochrane Library. Only papers written in English that analyzed the role of vitamin D in IBD were included. (3) Results: In vitro and animal studies reported that vitamin D signaling improves epithelial barrier integrity regulating the expression of several junctional proteins, defensins, and mucins, modulates the inflammatory response, and affects gut microbiome composition. Recent studies also suggest that vitamin D deficiency is highly prevalent among IBD patients and that low serum levels correlate with disease activity and, less clearly, with disease course. (4) Conclusions: An increasing body of evidence suggests some role of vitamin D in the pathophysiology of IBD, nonetheless the underlying mechanisms have been so far only partially elucidated. A strong correlation with disease activity has been reported but its implication in the treatment is still undefined. Thus, studies focused on this issue, the definition of vitamin D levels responsible for clinical effects, and the potential role of vitamin D as a therapeutic agent are strongly encouraged.

Keywords: Crohn’s disease; IBD; inflammation; micronutrient; ulcerative colitis.

Publication types

  • Review

MeSH terms

  • Animals
  • Gastrointestinal Microbiome
  • Humans
  • Inflammation / blood
  • Inflammation / prevention & control
  • Inflammatory Bowel Diseases / blood
  • Inflammatory Bowel Diseases / drug therapy
  • Inflammatory Bowel Diseases / etiology*
  • Intestines* / drug effects
  • Intestines* / microbiology
  • Intestines* / pathology
  • Vitamin D / blood*
  • Vitamin D / pharmacology
  • Vitamin D / therapeutic use
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / complications*
  • Vitamin D Deficiency / drug therapy
  • Vitamins / therapeutic use


  • Vitamins
  • Vitamin D