Folate deficiency

Causes:

reduced dietary intake (elderly, preganacy, etc)

drug inhibition (phenytoin, alcohol, 5-fluorouracil, methotrexate, and trimethoprim)

and malabsorption (coeliac disease, Whipple's disease)

Findings:

Clinically, no neurological symptoms as in B12 deficiency

Lab:

Macrocytic anemia (MCV >100) - RBCs are described as "macro-ovalocytes"

hypersegmented neutrophils

Plasma homocysteine levels are elevated

Low RBC folate level (confirm the diagnosis)

Urine methylmalonate level is normal