Carbidopa/levodopa induced severe vitamin B6 deficiency leading to symptomatic transfusion dependent microcytic Anemia

Parkinson's Disease is on the rise over the coming decades with expectations that more patients will be prescribed levodopa therapy. This case presents a patient with Parkinson's Disease who presented with severe symptomatic microcytic anemia. He was transfusion dependent during his extensive work up that occurred during both inpatient hospitalization and outpatient hematology visits. This was negative for iron deficiency, infectious etiology, hemolysis, active bleeding, bone marrow failure, myelodysplasia or hematologic malignancy. However, patient was found to have a critically low vitamin B6 level. Following initiation of vitamin B6 supplementation, patient's anemia resolved and was no longer transfusion dependent.