Influence of vitamin D on effectiveness of biologic therapy in patients with inflammatory bowel disease

Background Vitamin D (vitD) is an immunomodulatory hormone with a pivotal role in the pathogenesis of inflammatory bowel disease (IBD). Low vitD levels in patients with IBD are associated with active inflammation, disease severity, poor quality of life and adverse clinical outcomes. Our previous work suggests that pre-treatment with vitD may improve effectiveness of biologic drugs such as TNFα blockers.

Aims The aim of this study was to explore potential effects of serum vitD levels on treatment response to biologic therapy in patients with IBD.

Methods A retrospective cohort study was conducted to monitor ambulant treatment of patients with IBD receiving biologic therapies in relation to their vitD levels. Medical records and routine blood and stool samples of 162 adult patients with IBD were assessed. Samples were analysed for standard blood count, total 25OHD, albumin and inflammation markers (hsCRP, ESR and faecal calprotectin (fCal)) by standard methods. Biologic treatments (infliximab (IFX), its biosimilars (IFX-s), vedolizumab (VDZ) and ustekinumab (UST)) were administered over 1 year. Drug and anti-drug antibody (ADA) levels were measured using systems provided by Immundiagnostik AG, Bensheim, Germany.

Results 162 patients with IBD (91 Crohn’s disease (CD)/71 ulcerative colitis (UC)) were enrolled. At baseline, 40.7% were receiving vitD supplementation, 10.5% were biologic naïve and 50.6% were vitD deficient. No conclusive relations were found between baseline vitD or supplementation status with drug or ADA levels. However, higher vitD levels over time were associated with positive treatment response for patients on IFX and UST (p<0.05). 72.8% of patients responded to biologic treatment. Response was related to disease location in CD (p=0.011) and positively associated with naivety to biologics (p=0.040). Treatment responders had significantly higher Hb, iron, TSAT and significantly lower ESR, hsCRP and fCal at baseline.

Conclusions Our results support a protective role of vitD in patients with IBD treated with the biologic agents IFX and UST, shown here for the first time for UST. Interestingly, not the initial vitD status, but permanently sufficient vitD levels were decisive for improved treatment response. Therefore, regular vitD monitoring and long-term vitD substitution in patients with low vitD levels is indicated.

Publication History

Article published online:
28 August 2023