Vitamin D Deficiency and Its Correction in IBS Subtypes: Gender Differences and Biochemical Correlates

Background: Irritable Bowel Syndrome (IBS) is a prevalent functional gastrointestinal disorder with diverse subtypes. Recent evidence suggests a link between vitamin D deficiency and IBS; however, the association between vitamin D levels, IBS subtypes, and hematological-biochemical parameters remains unclear. Methods: This retrospective study included 240 patients diagnosed with IBS according to the Rome IV criteria at XXX XXX Medical Faculty Hospital. The patients were classified as diarrhea-predominant (IBS-D), constipation-predominant (IBS-C), or mixed-type (IBS-M). Serum vitamin D levels and various hematological and biochemical parameters were evaluated at baseline and after vitamin D supplementation. Sex-related differences were assessed. Results: Baseline vitamin D levels were low in all IBS subtypes, with no significant differences between the groups. Vitamin D supplementation resulted in a significant increase in serum vitamin D levels across all subtypes (p=0.001). No significant correlations were identified between vitamin D levels and hematological or biochemical parameters. Sex differences in vitamin D levels were only significant in the IBS-M group, both at baseline and post-treatment (p< 0.05). Conclusion: Vitamin D deficiency is prevalent among all IBS subtypes and significantly improves with supplementation, independent of the subtype. Although no associations were found between vitamin D levels and laboratory parameters, the observed sex differences in patients with IBS-M highlight the need for further research into potential sex-related pathophysiological mechanisms, which underscores the importance of considering vitamin D assessment and supplementation in IBS management.