VITAMIN B12 AND FOLATE DEFICIENCY ANEMIA PATHOGENESIS DIAGNOSIS AND PREVENTION OF NEUROLOGICAL COMPLICATIONS
Keywords:
vitamin B12, folate, megaloblastic anemia, methylmalonic acid, neuropathy.Abstract
Vitamin B12 and folate deficiency impair DNA synthesis and can cause megaloblastic anemia, but their clinical consequences are not interchangeable. Vitamin B12 deficiency may produce peripheral neuropathy, gait disturbance, and spinal cord dysfunction even when anemia and macrocytosis are absent. Delayed recognition can leave persistent neurological disability despite subsequent hematological recovery. This narrative review considers the biochemical basis of ineffective erythropoiesis, interpretation of vitamin assays and metabolic markers, investigation of dietary and absorptive causes, and selection of replacement therapy. Methylmalonic acid helps clarify selected uncertain B12 results, whereas homocysteine is less specific because it also increases in folate deficiency and other conditions. Treatment should not be delayed when neurological disease strongly suggests B12 deficiency. Folate replacement must be accompanied by assessment of B12 status because correction of anemia can conceal an unresolved neurological problem. Effective care also requires identifying irreversible causes that make long-term replacement necessary.References
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