# The role of vitamin D deficiency and modifiable risk factors in patients with Crohn’s disease

## TL;DR

This study explores how vitamin D deficiency is linked to Crohn’s disease and identifies factors that contribute to it.

## Contribution

The study identifies specific risk factors for vitamin D insufficiency in Crohn’s disease patients using regression analyses.

## Key findings

- Vitamin D levels were significantly lower in Crohn’s disease patients compared to healthy controls.
- Age, sex, iron levels, and 25-OH vitamin D were significant risk factors for vitamin D deficiency in CD patients.
- Vitamin D levels improved after Vedolizumab treatment in some patients.

## Abstract

Vitamin D insufficiency is usually seen in Crohn’s disease (CD). Our study aims to determine the risk factors for vitamin D insufficiency in CD patients.

Between May 2021 and December 2023, we enrolled 102 CD patients and 100 healthy people in our hospital who were eligible for the study. Changes in vitamin D levels were also analyzed. CD patients were divided into active and clinical remission, and further changes in micronutrient and vitamin D levels were analyzed. Lastly, risk factor analysis was conducted using univariate, multivariate, and LASSO regression analysis models.

The average age of CD patients was 38.91 ± 3.31 years, whereas the average age of the healthy people was 38.64 ± 2.26 years. Vitamin D levels were significantly lower in CD patients than in healthy controls (19.62 ± 2.68 vs. 22.68 ± 4.61), especially for patients with active CD. In 11 patients treated with vedolizumab, compared to the pre-treatment Vedolizumab group, vitamin D levels improved more dramatically post-Vedolizumab therapy. According to univariate analysis, Age (OR: 0.95, 95% CI 0.26-1.33, p=0.01), sex (OR: 0.26, 95% CI 0.25-0.99, p=0.03), recent biologics (OR: 0.54, 95% CI 0.44-1.25, p=0.02), iron (OR: 0.89, 95% CI 0.72-1.62, p=0.02), and total 25-OH vitamin D (OR: 1.25, 95% CI 1.02-1.99, p=0.02) did significantly differ between patients with and without vitamin D deficiency. After controlling for several variables, multivariate analysis revealed that a lower odds ratio was linked to increasing age at diagnosis (OR: 0.12, 95% CI 0.03-0.85, p=0.02), sex (OR: 0.58, 95% CI 0.44-0.95, p=0.01), iron (OR: 0.44, 95% CI 0.11-0.62, p=0.01), and 25-OH vitamin D total (OR: 0.48, 95% CI 0.25-0.95, p=0.03). In addition, Age, time since illness onset, and 25-OH vitamin D were found to be helpful indicators for CD patients using LASSO regression.

According to this study, vitamin D insufficiency was often linked to CD patients with active status and pre-treatment Vedolizumab. Furthermore, Age, time since illness onset, and 25-OH vitamin D were found to be significant risk factors for CD.