The Role of Vitamin D in Inflammatory Bowel Disease - Assessing Therapeutic and Preventive Potential of Supplementation and Food Fortification

Patterns of vitamin D testing and supplementation for children with inflammatory bowel disease in Australasia

Background and Aim

For children with inflammatory bowel disease (IBD), optimal levels of vitamin D are ascribed anti-inflammatory and essential immune system roles that are associated with reduced disease activity, lower postoperative recurrence, and higher quality of life. International guidelines for vitamin D testing and supplementation provide inconsistent recommendations. The aim of this study was to survey Australasian pediatric gastroenterologists to ascertain current practices of vitamin D testing and supplementation for children with IBD.

Methods

Members of the Australian Society of Pediatric Gastroenterology, Hepatology and Nutrition were invited to complete an online survey. Respondents were asked to provide information on frequency of vitamin D testing and supplementation, adherence, and benefits of vitamin D to children with IBD.

Results

Thirty-two (54%) pediatric gastroenterologists completed the survey: 27 (84%) from Australia and 5 (16%) from New Zealand. The majority (90%) tested vitamin D levels at diagnosis and follow up, although testing frequency varied (1-3 times/year) and only 8 (28%) tested seasonally. While 28 (88%) recommended supplementation based on serum levels, inconsistent cutoff values were used. Most respondents (n = 27) recommended Stoss (single dose) or vitamin D3 (daily for 8-12 weeks). The majority (84%) rated the overall benefit of optimal vitamin D levels at ≥6/10, although fewer (54%) rated the benefit to disease activity at ≥6/10.

Conclusions

The results indicate that standardized guidelines for vitamin D testing and supplementation for clinicians caring for children with IBD throughout Australasia are required. Consensus statements may optimize the care of children with IBD in this diverse geographical region.

Review article: The complex interplay between diet and Escherichia coli in inflammatory bowel disease

BACKGROUND

Although no causative microbe has been yet identified or successfully targeted in the treatment of inflammatory bowel disease (IBD), the role of Escherichia coli in the pathogenesis of Crohn's disease has attracted considerable interest.

AIM

In this review, we present a literature overview of the interactions between diet and E. coli and other Proteobacteria in the aetiology, outcomes and management of IBD and suggest future research directions.

METHODS

An extensive literature search was performed to identify in vitro studies and research in animal models that explored mechanisms by which dietary components can interact with E. coli or Proteobacteria to initiate or propagate gut inflammation. We also explored the effect diet and dietary therapies have on the levels of E. coli or Proteobacteria in patients with IBD.

RESULTS

Preclinical data suggest that the Western diet and its components influence the abundance, colonisation and phenotypic behaviour of E. coli in the gut, which may in turn initiate or contribute to gut inflammation. In contrast, the Mediterranean diet and specific dietary fibres may abrogate these effects and protect from inflammation. There are limited data from clinical trials, mostly from patients with Crohn's disease during treatment with exclusive enteral nutrition, with findings often challenging observations from preclinical research. Data from patients with ulcerative colitis are sparse.

CONCLUSIONS

Preclinical and some clinical trial data suggest that E. coli and other Proteobacteria interact with certain dietary components to promote gut inflammation. Well-designed clinical trials are required before dietary recommendations for disease management can be made.

Vitamin D deficiency associated with Crohn's disease and ulcerative colitis: a meta-analysis of 55 observational studies

PURPOSE

To investigate the association of serum levels of 25(OH)D and 1,25(OH)₂D₃ in healthy and non-healthy controls with Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

Three electronic databases: PubMed, EMbase and EBSCOhost CINAHL, were searched for observational studies to measure the relationship between serum levels of vitamin D (VitD) and CD (or UC).

RESULTS

Fifty-five studies were included in the meta-analysis. We found that mean serum 25(OH)D levels in patients with CD were significantly lower than those in healthy controls (MD: - 3.17 ng/mL; 95% CI - 4.42 to - 1.93). Results from the meta-analysis examining 1,25(OH)₂D₃ levels in Crohn's patients revealed higher levels in the CD group than in healthy (MD: 3.47 pg/mL; 95% CI - 7.72 to 14.66) and UC group (MD: 5.05 pg/mL; 95% CI - 2.42 to 12.52). Serum 25(OH)D levels were lower in the UC group than in the healthy control group (MD: - 2.52 ng/mL; 95% CI - 4.02 to - 1.02). In studies investigating the level of 1,25(OH)₂D₃ in UC and healthy control groups, the level of 1,25(OH)₂D₃ in the UC groups were found to be higher than that in the control groups (MD: 3.76 pg/mL; 95% CI - 8.36 to 15.57). However, the 1,25(OH)₂D₃ level in patients with UC was lower than that in CD groups (MD: - 6.71 pg/mL; 95% CI - 15.30 to 1.88). No significant difference was noted between CD patients and UC patients in terms of average serum 25(OH)D levels.

CONCLUSIONS

This study found that VitD levels were inversely related to CD and UC. Serum levels of 25(OH)D were lower in patients with CD and UC than in healthy people, and more than half of the patients had insufficient vitamin D levels. The serum level of 1,25(OH)₂D₃ in both the CD and UC groups was higher than that in healthy people.