Association of serum vitamin D levels on Helicobacter pylori infection: a retrospective study with real-world data.

OBJECTIVE: The aim of this study was to determine whether serum vitamin D levels are associated with H. pylori infection and whether low serum vitamin D levels are an independent risk factor for H. pylori infection. METHODS: We conducted a retrospective analysis of a multicenter cohort study from 2017 to 2019. A total of 415 H. pylori+ patients and 257 H. pylori- patients aged between 18 and 75 years with both 13 C-urea breath test and serum vitamin D level results were included from four hospitals. A questionnaire was used to collect information on potential factors influencing H. pylori infection. RESULTS: Serum vitamin D levels were significantly lower in the H. pylori+ group than in the H. pylori- group (16.7 ± 6.6 ng/ml vs. 19.2 ± 8.0 ng/ml, p < 0.05). Using a cutoff value of 20 ng/ml, the H. pylori infection rate was significantly higher in the vitamin D-deficient group (< 20 ng/ml) than in the vitamin D-nondeficiency group (≥ 20 ng/ml) (66.5% vs. 51.0%, p < 0.001). Ordered logistic regression analysis showed that serum vitamin D levels < 20 ng/ml (OR: 1.652, 95% CI: 1.160-2.351, p = 0.005), higher education levels (OR: 1.774, 95% CI: 1.483-2.119, p < 0.001), family size ≥ 4 (OR: 1.516, 95% CI: 1.081-2.123, p = 0.016), and lower annual income (OR: 1.508, 95% CI: 1.289-1.766, p < 0.001) were independent risk factors for H. pylori infection. CONCLUSION: Lower serum vitamin D levels may be associated with an increased risk of H. pylori infection, and lower serum vitamin D levels are an independent risk factor for increasing H. pylori infection rates. Randomized controlled trials are needed to determine whether supplementation with vitamin D can reduce H. pylori infection rates.