Gastro Flash Vol-11, No-1, 2026

Irritable bowel syndrome (IBS) is one of the most common disorders of gut-brain interaction, characterised by recurrent abdominal pain associated with altered bowel habits, constipation, diarrhoea, or a combination of both. It affects approximately 9–23% of the global population, with prevalence varying by geography and diagnostic criteria. In North America and Western countries, prevalence ranges between 10–20%, while population-based data from India suggest rates of 6.9% in women and 7.9% in men.

Abdominal pain is the hallmark of IBS and a key driver of disability, fluctuating in severity and often linked to defecation. Its mechanisms are multifactorial, including visceral hypersensitivity, abnormal motility, altered intestinal permeability, and brain-gut axis dysregulation.

Vitamin D3, long viewed as a simple micronutrient, is now recognised as a secosteroid hormone with endocrine, paracrine, and autocrine activity that extends well beyond skeletal physiology. Following cutaneous synthesis or dietary intake, it undergoes hepatic and renal activation to generate 1,25-dihydroxyvitamin D3, the metabolite that exerts genomic effects through the vitamin D receptor (VDR). VDR is highly expressed in the GI tract, regulating immunity, barrier function, and microbiome interactions.

Despite its physiological importance, vitamin D deficiency affects nearly one billion individuals globally, with far higher prevalence in India, with 70–90% across age groups.