METHODS:

By using the data from the National Inpatient Sample (NIS) database between 2002 and 2014, we identified the patients with vitamin D deficiency and IBD diagnosis using the International Classification of Diseases 9th version codes (ICD-9). The control group was the patients without vitamin D deficiency using the ICD-9 codes. We did multivariate logistic regression analysis to calculate the association between vitamin Ddeficiency and IBD.

RESULTS:

The study had total 101,137,145 patients. The vitamin Ddeficiency group had 339,418 patients (0.34%). We noticed that patients with vitamin D deficiency were older with mean age (63 vs 48), had more African American patients (17% vs 14%) and more female patients (67% vs 58%)(P< 0.001 for all). The vitamin D deficiency group had more patients with obesity (16% vs 7%) and more tobacco use (11% vs 10%)(P< 0.001 for all)(Figure 1). Using univariate analysis, we found patients with vitamin Ddeficiency had higher rate of IBD compared with patients without vitamin D deficiency (Odds Ratio [OR], 2.539, 95% confidence interval [CI], 2.474-2.605, P< 0.001), then we used multivariate logistic regression analysis, and after adjusting for potential cofounding factors, patients with vitamin D deficiency had a statistically significant higher rate of IBD (Odds Ratio [OR], 2.35, 95% confidence interval [CI], 2.285-2.417, P< 0.001) compared with patients without vitamin D deficiency (Figure 2).

CONCLUSION:

Based on our study we found that patients with vitamin D deficiency have two times higher risk of having IBD compared to patients without vitamin D deficiency. This raise the importance of screening for vitamin D deficiency in IBD patients. Further studies are needed to assess the role of vitamin D supplement in IBD course and outcome.