A 62 year old woman presents with progressive numbness in her feet and difficulty with balance. She underwent ileal resection several years ago for Crohn disease. Laboratory studies show hemoglobin 9.4 g per dL, mean corpuscular volume 112 fL, elevated homocysteine, and elevated methylmalonic acid. Which of the following deficiencies best explains her neurologic findings?
- A)Copper deficiency
- B)Folate deficiency
- C)Vitamin B12 deficiencyGABARITO
- D)Iron deficiency
- E)Niacin deficiency
Explicação
This patient has vitamin B12 deficiency causing megaloblastic anemia and subacute combined degeneration. B12 is required for methionine synthase and methylmalonyl CoA mutase, so deficiency elevates both homocysteine and methylmalonic acid. Neurologic deficits ... Ver explicação completa e trilha adaptativa →