Vitamin D status in irritable bowel syndrome and the impact of supplementation on symptoms: a systematic review and meta-analysis.

Background: latest studies have shown that vitamin D deficiency is related to the occurrence of irritable bowel disease (IBS), and taking vitamin D as a supplement can alleviate the symptoms of irritable bowel disease. However, clinical treatment of irritable bowel disease with vitamin D is controversial. Objective: we conducted a meta-analysis of all clinical trials to evaluate the associations between vitamin D and irritable bowel disease. Methods: we screened all randomized controlled trials that were published before December 20, 2021 from the following databases: Medline, Web of Science, China National Knowledge Infrastructure (CNKI), Cochrane Central, and Clinical Trial. We used RevMan 5.4.1 and Stata 16.1 to analyze the relevant data. The standardized mean difference (SMD) with 95 % confidence interval (95 % CI) was used to report effect sizes. Serum vitamin D concentration, risk of vitamin D deficiency among patients with IBS, Symptom Severity Score (SSS), and Quality of Life (QoL) score are the main endpoint outcomes in this study. Results: data from twelve clinical trials with 1331 IBS patients were included. Patients with IBS have relatively low vitamin D levels in their serum. Vitamin D supplementation improves the Quality of Life (QoL) score but has no significant effect on the Symptom Severity Score (SSS). Conclusions: vitamin D deficiency is associated with the pathogenesis of irritable bowel syndrome. Serum vitamin D levels decreased in patients with irritable bowel syndrome, and vitamin D supplementation could improve patient quality of life.