Vitamin D deficiency and corticosteroid use are risk factors for low bone mineral density in inflammatory bowel disease patients

Background: As several factors can contribute to low bone mineral density (BMD), we investigated the role of vitamin D in low BMD while controlling for other risk factors in inflammatory bowel diseases (IBD) patients. Methods: We conducted a prospective cross-sectional study between 2008 and 2012 in adult IBD patients. Demographic data including age, gender, ethnicity, BMI, along with disease type and location, vitamin D levels, prior corticosteroid use, and anti-TNF use were recorded and evaluated with DEXA results. Results: A total of 166 patients [105 Crohn's disease (CD), 61 ulcerative colitis (UC)] qualified for the study. Low BMD was found in 40 %, twice as frequently in CD than in UC (p = 0.048). Higher prevalence of low BMD was associated with those of male gender (p = 0.05), Asian ethnicity (p = 0.02), and history of corticosteroid use (p = 0.001). Age, body mass index, or disease location did not increase the risk of low BMD. The overall prevalence of low vitamin D was 60 %, with insufficiency (25-hydroxy levels between 20 and 30 ng/mL) found in 37 % and deficiency (levels <20 ng/mL) found in 23 % of the patients. Vitamin D insufficient and deficient patients were two times (p = 0.049) and almost 3 times (p = 0.02) as likely to have low BMD, respectively. Conclusions: Low vitamin D, male gender, Asian ethnicity, CD, and corticosteroid use significantly increased the risk of having low BMD, while age and disease location did not affect BMD in our IBD population. It remains important to evaluate for vitamin D nutritional deficiency and limit corticosteroid use to help prevent low BMD in IBD patients.