Vitamin B12 deficiency has traditionally been associated with strict vegetarian diets; however, recent evidence suggests that a substantial proportion of non-vegetarian Indians also exhibit suboptimal B12 levels . Despite regular intake of animal products, studies from India report prevalence rates ranging from 40–70% across different populations , indicating that dietary intake alone does not fully explain the burden. This paradox highlights the influence of metabolic, pharmacological, and gastrointestinal factors that may impair B12 absorption or utilization.
One important contributor is long-term use of commonly prescribed medications , particularly metformin and proton pump inhibitors (PPIs) . Metformin interferes with calcium-dependent absorption of the B12–intrinsic factor complex in the terminal ileum, while chronic PPI therapy reduces gastric acid secretion necessary for…
