Higher 25-hydroxyvitamin D levels are associated with greater odds of remission with anti-tumour necrosis factor-α medications among patients with inflammatory bowel diseases

Background Vitamin D has been linked to disease activity among patients with inflammatory bowel diseases (IBD). Prior investigation has also suggested that vitamin D levels may affect duration of therapy with anti-tumour necrosis factor- (anti-TNF-) medications among patients with IBD. Aim To evaluate the relationship between vitamin D levels and odds of reaching remission while on an anti-TNF- medication. Methods A total of 521 IBD patients enrolled in the Brigham and Women's IBD Centre database were eligible for inclusion. Patients treated with anti-TNF-alpha therapy who had vitamin D levels drawn within 6months prior or 2weeks after initiation of anti-TNF-alpha medication and who had reported remission status at 3months were included. A logistic regression model adjusting for age, gender, IBD diagnosis, anti-TNF-alpha medication (infliximab vs. adalimumab) and first or subsequent anti-TNF-alpha medication was used to identify the effect of vitamin D level on initial response to anti-TNF-alpha therapy. Results A total of 173 patients were included in the final analysis. On logistic regression, patients with normal vitamin D levels n = 122 at the time of anti-TNF- medication initiation had a 2.64 increased odds of remission at 3months compared to patients with low vitamin D levels n = 51 when controlling for age, gender, diagnosis, type of anti-TNF-alpha medication and first or subsequent anti-TNF-alpha medication (OR = 2.64, 95% CI = 1.31-5.32, P = 0.0067). Conclusions These findings suggest that vitamin D levels may influence initial response to anti-TNF-alpha medication and that low vitamin D levels may pre-dispose patients to decreased odds of remission.