Vitamin B12 Deficiency: Biological Mechanisms, Diagnostic Developments and Evidence-supported Therapeutic Approaches: A Comprehensive Review

Abstract

Cobalamin, often known as vitamin B12, is a water-soluble vitamin that is necessary for one-carbon metabolism, erythropoiesis, DNA synthesis, and neurological integrity. Vitamin B12 deficiency is still a major global health issue despite its vital physiological functions; it is particularly common in vegetarians, pregnant women, babies, older adults, and people with metabolic or gastrointestinal diseases. The current research on vitamin B12 deficiency's epidemiology, biochemical roles, absorption methods, etiology, clinical manifestations, diagnostic indicators, and treatment options is compiled in this review. With the growing recognition of subclinical insufficiency, proper identification requires the use of functional biomarkers like homocysteine and methylmalonic acid. Clinical consequences include neuropathy, megaloblastic anemia, adverse pregnancy outcomes, and delayed cognitive development. High-dose oral medicine, Sucrosomial formulations, and better screening techniques are examples of treatment innovations that have improved management outcomes. In high-risk communities, public health interventions like targeted supplementation and dietary fortification are still crucial.  Greater availability and preventative measures are supported by ongoing advancements in molecular biology and biotechnological production.  In general, minimizing the long-term neurological and systemic effects of vitamin B12 insufficiency requires early diagnosis and immediate action.