Abstract
Background
Vitamin D is a critical factor in bone remodelling, calcium absorption and may promote anti-inflammatory cytokines in the gut. Inflammatory bowel disease (IBD) is associated with a reduction in serum Vitamin D levels and a chronic inflammatory state, both of which are strong risk factors for bone density loss affecting IBD patients. Despite European and North American IBD maintenance guidelines for Vitamin D monitoring and bone density scans, there are limited North American investigations into factors influencing serum Vitamin D levels in the IBD patient population specifically.
Aims
We investigated whether patient demographics, disease severity indexes and/or inflammatory markers were linked to low serum Vitamin D levels in our IBD patients. We also established the extent of Vitamin D serum deficiencies and supplementation rates in our IBD patients.
Methods
A retrospective chart review of a single clinician’s practice at London Health Science Centre, Victoria Hospital, over the past 20 months, was performed to: 1) assess the frequency of low serum 25-OH Vitamin D (25-OH D) in the IBD patient population and 2) determine whether patient disease severity was linked to lower 25-OH D levels. A multivariate regression analysis was performed assessing Crohn’s Disease (CD) or Ulcerative Colitis (UC) patient factors: age, sex, disease duration, seasonality, current pharmacologic treatments, past surgeries, CD Activity Index, UC Mayo score, C-reactive protein, and fecal calprotectin (Fcal) level.
Results
175 IBD patients had at least one 25-OH D measurement with 71 patients actively on Vitamin D therapy. Of UC and CD patients who were not on Vitamin D therapy, 63% (17/27) and 79% (61/77) were 25-OH D deficient, respectively. 25-OH D levels in the CD population was associated with Vitamin D supplementation (regression coefficient [RC] 23.99, 95% confidence interval [CI] 14.54 to 33.45), summer season ([RC] 9.90, [CI] 0.56 to 19.24), and past bowel resection ([RC] -10.61, [CI] -20.48 to -0.76). 25-OH D levels in the UC population was associated with Vitamin D supplementation (regression coefficient [RC] 47.23, 95% confidence interval [CI] 27.62 to 66.83), and Mayo severity scores ([RC] -23.01, [CI] -41.82 to -4.20). Fcal (78 patients) was inversely associated with 25-OH D levels but the trend was not significant.
Conclusions
Overall, 25-OH D levels were lower in both the UC and CD patient populations relative to the already deficient Canadian population. However, IBD patients are responsive to Vitamin D supplementation. Tools with more objective evidence of disease severity such as UC Mayo score and fcal should be prioritized for identifying the IBD population requiring supplementation.
Funding Agencies
None
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