Effect of Vitamin D on Inflammatory and Oxidative Stress Biomarkers, Gastrointestinal Symptoms and Health Related Quality of Life in Irritable Bowel Syndrome Patients

Abstract

OBJECTIVES: Irritable bowel syndrome (IBS) patients display persistent signs of low-grade mucosal inflammation (1) and alterations in the oxidant-antioxidant enzymatic system (2). METHODS: A total of ninety IBS patients, as defined by the Rome III criteria, participated in this double blind, randomized, placebo-controlled 6-month intervention. Participants were randomly categorized to receive either 50,000 IU vitamin D3 or a placebo fortnightly. Patients reported their IBS symptoms monthly during intervention periods. IBS specific quality of life (IBS-QoL) and biochemical factors (such as IL-17, IL-10, TNFα, malondialdehyde (MDA) and total antioxidant capacity (TAC)) were assessed at the baseline and post-intervention. RESULTS: A significantly greater improvement in IBS symptoms such as abdominal pain and distention, flatulence, rumbling, and overall GI symptoms (except dissatisfaction with bowel habits) were observed over the 6-month intervention period in the patients receiving the vitamin D. In the intervention group, serum levels of IL-17 and MDA significantly decreased, and TAC and IL-10 levels significantly increased compared to the placebo group post-intervention. No significant differences were seen between the groups regarding TNFα levels. CONCLUSION: Vitamin D has anti-inflammatory and antioxidant effects in IBS patients. The present study suggests the beneficial effects of vitamin D on the symptoms of IBS.