Published online Sep 7, 2022. doi: 10.3748/wjg.v28.i33.4834
Peer-review started: March 14, 2022
First decision: May 9, 2022
Revised: May 23, 2022
Accepted: August 6, 2022
Article in press: August 6, 2022
Published online: September 7, 2022
Processing time: 169 Days and 16.6 Hours
Patients with inflammatory bowel disease (IBD) are prone to several nutritional deficiencies, including iron, vitamin B12 and vitamin D. However, there is a lack of data on vitamin C deficiency in this population, as well as the impact of clinical, biomarker and endoscopic disease severity on the development of vitamin C deficiency.
As IBD patients are already at risk of malnutrition and as vitamin C deficiency is an easily reversible condition, it would be valuable to understand the prevalence of and factors associated with vitamin C deficiency in this population.
The primary objective assessed the prevalence of vitamin C deficiency in IBD patients. Secondary objectives evaluated proportions with deficiency between active and inactive IBD - using clinical, laboratory and endoscopic data - to better identify those at risk of deficiency.
In this retrospective study, clinical, laboratory and endoscopic data were collected from all Crohn’s disease (CD) and ulcerative colitis (UC) patients who had available plasma vitamin C levels presenting to the IBD clinic at a single tertiary care center from 2014 to 2019. Of 353 subjects who met initial search criteria using a cohort discovery tool, 301 ultimately met criteria for inclusion in the study. The primary aim described vitamin C deficiency (≤ 11.4 μmol/L) rates in IBD, with secondary analyses comparing proportions with deficiency between active and inactive IBD. Multivariate logistic regression analysis evaluated factors associated with deficiency.
In 301 IBD patients, 21.6% had vitamin C deficiency, including 24.4% of CD 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 higher proportions of deficiency compared to those without. Other factors associated with vitamin C deficiency included the presence of penetrating disease (P = 0.03), obesity (P = 0.02) and current biologic medication use (P = 0.006). On multivariable analysis, the objective inflammatory marker utilized for analysis (CRP) was the only factor associated with deficiency (odds ratio = 3.1, 95% confidence interval: 1.5-6.6, P = 0.003).
This study provides the largest data on vitamin C deficiency in patients with IBD, uniquely assesses factors associated with deficiency and provides rigorous assessment of inflammatory status using objective markers. Vitamin C deficiency was common in IBD, particularly those with objective markers of active luminal or penetrating disease. As vitamin C deficiency exists in over one-fifth of IBD patients, it is essential to identify and treat this easily reversible condition in this population.
Future prospective studies with well characterized cohorts, and data on diet, other micronutrient deficiencies, endoscopic assessment, and vitamin C supplementation, may be warranted to further elucidate factors associated with vitamin C deficiency and the impact of supplementation on clinical course in IBD patients.