Effect of vitamin D on gastrointestinal symptoms and health‐related quality of life in irritable bowel syndrome patients: a randomized double‐blind clinical trial

Background Low‐grade mucosal inflammation and immune activation are involved in the pathogenesis of irritable bowel syndrome ( IBS ). Furthermore, IBS symptoms are associated with a significantly higher prevalence of psychological distress, which in itself results into an impaired quality of life (QoL). Vitamin D could ameliorate the symptoms of patients suffering from IBS through its beneficial effects on psychological factors and inflammation. Methods A total of 90 IBS patients participated in this double‐blind, randomized, placebo‐controlled study. Participants were randomly selected to receive either 50 000 IU vitamin D 3 or a placebo fortnightly for a period of 6 months. Patients reported their IBS symptoms at the baseline and monthly during intervention periods. The IBS severity score system ( IBSSS ) and IBS ‐specific QoL questionnaires were used at the baseline and postintervention. Key Results Over the 6‐month intervention period, a significantly greater improvement in IBS symptoms such as abdominal pain and distention, flatulence, rumbling, and overall gastrointestinal ( GI ) symptoms (except dissatisfaction with bowel habits) was observed in the patients receiving vitamin D as compared to the placebo group. The IBSSS and the IBS ‐QoL scores in the vitamin D group significantly improved compared to the placebo group postintervention (mean IBSSS score change: −53.82 ± 23.3 vs −16.85 ± 25.01, p < 0.001, respectively; mean IBS ‐QoL score change: 14.26 ± 3 vs 11 ± 2.34, p < 0.001, respectively). Conclusions & Inferences Vitamin D seems to be an effective and safe option to improve QoL and symptoms of IBS . ClinicalTrials.gov ( NCT 02579902).