Prevalence and factors associated with vitamin C deficiency in inflammatory bowel disease

BACKGROUND Patients with inflammatory bowel disease(IBD) are prone to several nutritional deficiencies. However, data are lacking on vitamin C deficiency in Crohn’s disease(CD) and ulcerative colitis(UC) patients, as well as the impact of clinical, biomarker and endoscopic disease severity on the development of vitamin C deficiency.AIM To determine proportions and factors associated with vitamin C deficiency in CD and UC patients.METHODS In this retrospective study, we obtained clinical, laboratory and endoscopic data from CD and UC patients presenting to the IBD clinic at a single tertiary care center from 2014 to 2019. All patients had an available plasma vitamin C level. Of 353 subjects who met initial search criteria using a cohort discovery tool, 301ultimately met criteria for inclusion in the study. The primary aim described vitamin C deficiency(≤ 11.4 μmol/L) rates in IBD. Secondary analyses compared proportions with deficiency between active and inactive IBD. Multivariate logistic regression analysis evaluated factors associated with deficiency.RESULTS Of 301 IBD patients, 21.6% had deficiency, including 24.4% of CD patients and 16.0% of UC patients. Patients with elevated C-reactive protein(CRP)(39.1% vs 16.9%, P < 0.001) and fecal calprotectin(50.0% vs 20.0%, P = 0.009) had significantly higher proportions of deficiency compared to those without. Penetrating disease(P = 0.03),obesity(P = 0.02) and current biologic use(P = 0.006) were also associated with deficiency on univariate analysis. On multivariate analysis, the objective inflammatory marker utilized for analysis(elevated CRP) was the only factor associated with deficiency(odds ratio = 3.1, 95%confidence interval: 1.5-6.6, P = 0.003). There was no difference in the presence of clinical symptoms of scurvy in those with vitamin C deficiency and those without.CONCLUSION Vitamin C deficiency was common in IBD. Patients with elevated inflammatory markers and penetrating disease had higher rates of vitamin C deficiency.