Vitamin D deficiency in inflammatory bowel disease: prevalence and predictors in a Norwegian outpatient population

Abstract

Background and aim: Vitamin D deficiency is common in inflammatory bowel disease (IBD). The aims of the present study were to determine the prevalence of vitamin D deficiency and to identify clinical and epidemiological variables associated with vitamin D deficiency in an outpatient population with IBD.

Methods: Participants were recruited from nine hospitals in the southeastern and western regions of Norway as part of an observational, multicentre study from March 2013 to April 2014. Clinical and epidemiological data were collected by interview and from medical records. All analyses of serum 25-hydroxyvitamin D (25-OH-D) were performed in the same laboratory.

Results: In total, 49% (200/408) of the patients had a 25-OH-D concentration <50 nmol/L, including 53% (122/230) of the Crohn’s disease (CD) patients and 44% (78/178) of the ulcerative colitis (UC) patients. In CD patients, disease activity, measured as the HBI, was inversely associated with vitamin D deficiency. No such association was observed with the Simple Clinical Colitis Activity Index (SCCAI) scores in UC, but in UC patients, vitamin D deficiency was associated with elevated faecal calprotectin >100 mg/kg. In patients with CD, there were significantly more relapses during the previous year in patients with vitamin D deficiency.

Conclusions: Vitamin D deficiency was common, especially in CD, and was associated with increased disease activity, a relapsing disease course and higher inflammatory activity.

Keywords:

• Inflammatory bowel disease
• vitamin D deficiency
• epidemiology

Acknowledgements

Thanks to all participants in the Vitality Study group who assisted with the data collection.

Authorship statement

Svein Oskar Frigstad is acting as the submission’s guarantor. All authors have made substantial contributions to (1) the conception and design of the study, or acquisition of data or analysis and interpretation of data, (2) drafting the article and revising it critically, and (3) final approval of the version to be submitted. All authors had full access to the data in the study and have approved the final version of the article, including the authorship list. The manuscript included related data and tables has not been previously published and the manuscript is not under consideration elsewhere.

Disclosure statement

The authors report no conflicts of interest.

Funding

This work was supported by an unrestricted research grant from Tillotts Pharma and the Østfold Hospital Trust.