Vitamin D Deficiency is Widely Prevalent in South Asian Patients with Inflammatory Bowel Disease

Abstract

Purpose: There has been resurgent interest in recent years in the pro-hormone vitamin D beyond its classical role in bone metabolism to its role and plausible effects on immune regulation and inflammatory bowel disease (IBD). We postulated a wide prevalence of vitamin D deficiency in South Asian patients with implications for the control of their IBD. The aim of our study was to review vitamin D assessment in a South Asian IBD cohort. Methods: We conducted a retrospective review of 102 South Asian patients attending IBD clinics in our institution. Clinical data including demographics, disease characteristics (Montreal classification) and therapy were obtained from electronic record review. Serum 25-hydroxyvitamin D (25-OHD) concentrations were recorded in all patients tested and in all having serial measurements. Results: Of 102 patients reviewed 54 were male. The median age was 38 years (range 16-80), and mean disease duration was 9.4 years. Seventy-three patients had ulcerative colitis (UC) and 29 had Crohn's disease (CD). Five patients were current or ex smokers (4.9%). Vitamin D status was assessed in 51 patients (50%), 25 had serial measurements. Median 25-OHD was 8.85 (range 3.3-44.4). Fifty patients had levels <25 ng/ml consistent with deficiency and all 51 had insufficient levels <50 ng/ml. Of the patients with deficiency 34 had UC and 16 had CD. Of the UC patients, 17 had pancolitis, 13 had left sided disease and 4 proctitis. Of the CD patients 5 had penetrating disease and 4 had stricturing disease. Forty-two of the deficient patients had received steroids and 29 received immunomodulatory therapy (27 azathioprine, 3 methotrexate, 1 cyclosporin, 2 6MP, 10 infliximab, 6 adalimumab. Seven deficient patients (4 CD, 3 UC) required a colectomy and the mean 25-OHD level in this group was 10.7 (range 4.0-20.1 ng/ml). Mean time to surgery was 3.6 years (range 0-8 years). Of the CD patients 1 had a subtotal colectomy, 3 had hemicolectomy and of the UC patients 2 had subtotal colectomy and 1 had total colectomy. Conclusion: There was a high prevalence of Vitamin D deficiency in our patient cohort although assessment was suboptimal and probably reflective of a wider experience with disparate practices elsewhere. Patients with vitamin D deficiency appeared to have a more aggressive disease course with 14% of deficient patients requiring surgical management. The immunopathogenesis of vitamin D in IBD is a science in evolution underpinning exciting implications for gastroenterological research. Meanwhile vitamin D deficiency is under-recognised and consequently undertreated with likely implications for adequate disease control in this potentially vulnerable group.