P049 Prevalence and factors associated with vitamin D deficiency in patients with inflammatory bowel disease on biologic therapies
K. Sugrue, D. Fitzgerald, M. Buckley, J. McCarthy, D. Farrell*
Mercy University Hospital, Department of Gastroenterology, Cork, Ireland
Vitamin D is an important regulator of the immune system. Vitamin D deficiency, defined as serum levels less than 50 nmol/L, is common in patients with inflammatory bowel disease (IBD), with prevalence rates varying considerably from 16% to 95% (Mouli et al. 2014). An Irish study by Raftery et al.  found mean serum vitamin D levels of 59.8nmol/L in a sample of 119 patients with Crohn’s disease. A number of factors have been found to be associated with vitamin D deficiency in patients with IBD, including increased disease activity, older age, longer disease duration, and smoking status. However, to date, no study has investigated the prevalence and factors associated with vitamin D deficiency in patients with IBD on biologic therapies.
A cross-sectional survey was undertaken on a consecutive sample of 70 individuals with IBD at a tertiary IBD referral centre in Southern Ireland. Serum 25-OH vitamin D levels were measured. The Harvey–Bradshaw Index and the Mayo Score were used to assess disease activity in individuals with Crohn’s disease and ulcerative colitis, respectively. Data were also collected on disease type, disease duration, treatment type, smoking, and educational status between April and August 2015. Descriptive and inferential analysis was used to analyse data.
Serum 25-OH vitamin D levels ranged from 20–115 nmol/L, with a median vitamin D level of 48 nmol/L identified. In total 60% (n = 42/70) of the sample had vitamin D deficiency, of which a greater proportion were female (n 23) and had a diagnosis of ulcerative colitis (n = 27). Participants with Crohn’s disease (40.5 nmol/L vs 50 nmol/L, p = 0.515) and ulcerative colitis (46 nmol/L vs 55 nmol/L, p = 0.119) in active disease states had lower median vitamin D levels than those in remission; however, no statistical significance was found. Further, no significant associations were identified between vitamin D deficiency and the other demographic and clinical factors measured.
Vitamin D deficiency is common in patients with IBD on biologic therapies; however, no demographic or clinical variables were found to be statistically associated. Routine screening of vitamin D deficiency is warranted.
 Raftery T, Merrick M, Healy M, Mahmud N, O’ Morain C, Smith S, McNamara D, O’ Sullivan M. (2015) Vitamin D Status is associated with intestinal inflammation as measured by fecal calprotectin in Crohn’s disease in clinical remission. Digestive Diseases and Sciences 60(8): 2427-2435.