Unraveling the Enigma: Food Cobalamin Malabsorption and the Persistent Shadow of Cobalamin Deficiency.

Food cobalamin malabsorption (FCM) represents a prevalent, often underdiagnosed, etiology of vitamin B12 deficiency, particularly within an aging population. Unlike pernicious anemia, an autoimmune disorder targeting intrinsic factor, FCM stems from the impaired release of cobalamin from food proteins, primarily due to age-related gastric changes, medication-induced gastric hypochlorhydria, metformin, or non-immune atrophic gastritis. The clinical presentation of FCM mirrors that of general cobalamin deficiency, encompassing a spectrum of neurological (peripheral neuropathy, cognitive decline), hematological (megaloblastic anemia), and gastrointestinal (glossitis, anorexia) manifestations. Given the potential for irreversible neurological sequelae, early detection and intervention are paramount. High-dose oral cobalamin (125-250 mcg daily) has demonstrated efficacy, offering a convenient and cost-effective alternative to parenteral administration.