A 30 years old came with complaints of easy fatigability

A 30 years old came with complaints of easy fatigability, exertional dyspnea, and weight loss. She also complains of frequent falls. physical examination revealed there was a bilateral decrease in vibration sense. Her hemoglobin levels were 8.2g%. She was treated with folate. Her anemia improved but neurological symptoms worsened. Which of the following is the most probable reason for her condition?

A. Folate not absorbed

B. Unmasked pyridoxine deficiency

C. Deficiency of folate reductase in CNS

D. Folate therapy caused rapid use of Vit B12 stores aggravating symptoms

ANSWER= D. Folate therapy caused rapid use of Vit B12 stores aggravating symptoms
Explain:- Vitamin B12 is required for the recycling of tetrahydrofolate, the form of folate that is needed for DNA synthesis. In keeping with this relationship, the anemia of vitamin B12 deficiency is reversed with the administration of folate. By contrast, folate administration does not prevent and may, in fact, worsen the neurologic symptoms