VITAMIN D AND INFLAMMATORY DISEASES OF THE SMALL AND LARGE INTESTINE: FROM MECHANISTIC INSIGHTS TO CLINICAL PRACTICE (REVIEW)

Abstract

Inflammatory diseases of the small and large intestine (IBD) constitute a major medical and social challenge due to their high prevalence, chronic course, and substantial impact on patients’ quality of life. Immune dysregulation, altera- tions in the microbiome, and genetic susceptibility play central roles in the pathogenesis of these disorders, interacting within a complex network of inflammatory pathways. Vitamin D, traditionally recognized for its role in calcium–phosphorus homeostasis, has emerged over recent decades as a key immunomodulatory and anti-inflammatory factor. It influences the integrity of the epithelial barrier of the small and large intestine, modulates cytokine production, and regulates T-cell activity. This article summarizes current evidence on the involvement of vitamin D in IBD pathogenesis, the high prevalence of its deficiency in affected individuals, and clinical trial data demonstrating the potential benefits of correcting vitamin D status. Particular attention is given to indi- vidualized dosing strategies, interactions with immunosuppressive agents, and the prospects of incorporating vitamin D into combined therapeutic regimens. The presented findings underscore the need for further research aimed at optimizing management strategies for IBD patients in the context of their vitamin D levels. With growing interest in the role of micronutrients in maintaining immune homeostasis, evaluating the effects of vitamin D on pathophysiological processes in IBD is crucial for advancing personalized therapeutic approaches. The synthesized evidence provides a scientific foundation for the development of updated clinical guidelines and for deeper investigation of the relationship between nutritional status and the course of chronic inflammatory processes in the small and large intestine.