Which findings would most support a diagnosis of vitamin B12 deficiency?

Which findings would most support a diagnosis of vitamin B12 deficiency?

• A. Abdominal pain relieved by meals
• B. Paresthesias and glossitis with macrocytic anemia and hypersegmented neutrophils
• C. Elevated ferritin levels
• D. Positive anti-tissue transglutaminase antibody

Answer: (B)

Vitamin B12 deficiency presents with a set of findings that reflect both impaired DNA synthesis and nerve demyelination. The combination of paresthesias and glossitis with macrocytic anemia and hypersegmented neutrophils is classic. Macrocytosis arises because impaired DNA replication slows the production of red blood cells, leading to larger-than-normal cells; hypersegmented neutrophils are a hallmark of megaloblastic processes. Neurologic symptoms like paresthesias come from demyelination of the dorsal columns and other pathways, which is more specific to B12 deficiency than to folate deficiency alone (folate deficiency can cause macrocytosis and glossitis but typically lacks neuro signs). Glossitis reflects mucosal atrophy from rapid cell turnover being disrupted. Other findings listed don’t point as specifically to B12 deficiency. Elevated ferritin suggests iron-related processes or inflammation, not the megaloblastic picture. A positive anti-tissue transglutaminase antibody points toward celiac disease, which can cause malabsorption but doesn’t by itself explain the neuro signs and the hypersegmented neutrophils seen with B12 deficiency.

Vitamin B12 deficiency presents with a set of findings that reflect both impaired DNA synthesis and nerve demyelination. The combination of paresthesias and glossitis with macrocytic anemia and hypersegmented neutrophils is classic. Macrocytosis arises because impaired DNA replication slows the production of red blood cells, leading to larger-than-normal cells; hypersegmented neutrophils are a hallmark of megaloblastic processes. Neurologic symptoms like paresthesias come from demyelination of the dorsal columns and other pathways, which is more specific to B12 deficiency than to folate deficiency alone (folate deficiency can cause macrocytosis and glossitis but typically lacks neuro signs). Glossitis reflects mucosal atrophy from rapid cell turnover being disrupted.

Other findings listed don’t point as specifically to B12 deficiency. Elevated ferritin suggests iron-related processes or inflammation, not the megaloblastic picture. A positive anti-tissue transglutaminase antibody points toward celiac disease, which can cause malabsorption but doesn’t by itself explain the neuro signs and the hypersegmented neutrophils seen with B12 deficiency.