A new randomized controlled trial (RCT) found no evidence to support the role of vitamin D in the management of irritable bowel syndrome (IBS) symptoms or improving the quality of life (QoL) of the patients. The findings were published in the European Journal of Nutrition.
Although many previous RCTs have shown a benefit of vitamin D supplementation in patients with IBS, they were either underpowered or had design limitations. Researchers conducted yet another adequately powered RCT to test the hypothesis that moderate-dose vitamin D supplementation for 12 weeks would reduce symptom severity in a UK IBS population.
In a double-blind, placebo-controlled trial, 135 individuals with IBS recruited from a UK community setting during winter months between December 2017 and March 2019 were randomly assigned to receive either vitamin D 3000 IU daily (n=68) or placebo (n=67) for 12 weeks.
Vitamin D supplementation effectively increased the total circulating serum 25(OH)D levels relative to the placebo at 12 weeks (P<.0001) and relative to the baseline levels (P<.001).
The vitamin D arm showed no significant difference vs the placebo arm in terms of total IBS symptom severity (220.3±93.73 vs 194.2±97.67; P=.147) as well as in terms of individual symptom scores for severity of pain, days with pain, distention, satisfaction with bowel habit and effect of symptoms on life. There was no significant correlation between change in serum 25(OH)D levels and change in total symptom severity (Spearman’s rank correlation coefficient, −0.071; P=.434).
Similarly, there was no significant difference between the change in QoL score from baseline to exit between the vitamin D and placebo arms (P=.525). Furthermore, there was no correlation between change in serum 25(OH)D levels and change in QoL (Spearman’s rank correlation coefficient, −0.031; P=.73).
"Notwithstanding any benefit of vitamin D on IBS symptomology, IBS patients should be screened for vitamin D status and supplemented appropriately for general health reasons," the authors suggested.
