Vitamin D and bone health in Inflammatory Bowel Disease
Grace Harkin, Aoife Murray, Áine Keogh, Rahim Khan, Andrew Smyth, Eoin Slattery
Gastroenterology Department, University Hospital Galway
Vitamin D deficiency impacts on bone health. Evolving evidence suggests its role in perpetuating chronic inflammation. Epidemiological studies suggest an assoication between Vitamin D and inflammatory bowel disease (IBD);although causative linkage remains elusive for numerous reasons. European guidelines suggest screening for bone health as per the general population (particularly cumulative steroid use>3months).
To assess the quality of management of bone health in patients with severe IBD in a busy tertiary referral hospital. A secondary aim was to assess the prevalence of Vitamin D insufficiency.
We performed a retrospective cohort study of patients with IBD attending Galway University Hospitals currently receiving a biologic agent (infliximab, adalimumab, golimumab and vedolizumab). Patient’s records were interrogated for evidence of bone health screening (Vitamin D, Parathyroid Hormone (PTH), Serum Calcium, Phosphate, Magnesium, and Dual-Energy X-Ray Absorptiometry (DEXA) scans).
Of 158 patients (75 female) currently receiving a biologic agent, 74.7%(n=118) have Crohn’s Disease (CD). Mean age is 39 (13)years with median disease duration of 7 (4-14)years. Vitamin D level (within the last 3years) was measured in 66.5%(n=105) of patients. Overall mean Vitamin D level was 57.5IU (27.0IU), with no difference between patients with CD (mean 57.0IU (28.0IU)) and Ulcerative Colitis (UC, mean 59.3IU (23.4IU))(p=0.72). Of those with measured Vitamin D, 72.4%(n=76) were either deficient (<50IU) or insufficient (50-75IU). Mean calcium (n=153) was 2.33mmol/L(0.09mmol/L), Alkaline Phosphate (n=153) 71u/l(21u/l), phosphate (n=146) 1.10mmol/L(0.19mmol/L), magnesium (n=41) 0.83mmol/L(0.09mmol/L) and median PTH (n=7) was 34pg/ml(19.7-61.9pg/ml). There were no differences between CD and UC, or by Vitamin D deficiency. DEXA scans were performed in 12.7%(n=20).
The overwhelming majority(72.4%)of our patients assessed for bone health are Vitamin D insufficient/deficient using conventional methods of assessment. No difference was seen between patients with CD and UC. A third of patients had not been screened for Vitamin D status (within the last 3years) with only a minority having DEXA scans performed(due to logistical reasons). The true role of Vitamin D in the aetio-genesis and future health of IBD remains unclear, nevertheless efforts should be undertaken to improve bone health assessment given the frequency of Vitamin D insufficiency, and particularly increased uptake of DEXA needs to be addressed.