Case Presentation: Ms. Y is a 40-year-old female with a remote history of iron deficient anemia who presented with one month of progressive shortness of breath, palpitations, fatigue. She was found to have a severe anemia, with a hemoglobin of 3.9 during routine outpatient lab work. She intentionally lost 80 lbs over the past 2 years through switching to a vegetarian diet with occasional animal products. She did not note any melena, hematochezia, hematemesis and did not endorse menorrhagia. On presentation, she was tachycardic, with conjunctival pallor, and a holosystolic ejection murmur appreciated over the left sternal border. Neurologic exam was within normal limits. Initial laboratory workup revealed a pancytopenia with a hemoglobin of 3.5, MCV of 88, absolute reticulocyte count of 0.008 (109/L), WBC of 3.2 (10³ µL), and platelets of 105 (10³ mcL). Blood smear was significant for hyper segmented neutrophils, teardrop cells, and hypochromia. Ultimately, her B12 level was noted to be <50 and the patient was started on daily B12 1000 mcg IM injections while inpatient and transitioned to B12 1000 mcg tablets daily prior to discharge for severe B12 deficient anemia. Intrinsic factor antibody was found to be negative. After 2 weeks of B12 therapy, hemoglobin had increased to 6.2 and reticulocytes had begun to appropriately compensate. Of note, she was spiritually opposed to receiving any form of blood products.
Discussion: Vitamin B12 is derived from animal protein. Adherence to a vegan diet has been widely recognized as a potential cause of B12 deficient anemia. This form of anemia typically takes a long time to develop, as the body can provide sufficient stores of B12 for up to 2 to 4 years (Roman, et. al 2013). B12 deficiency is also typically accompanied by significant neurological and potential psychiatric symptoms such as: weakness, ataxia, paresthesia, depression and impaired memory (Stabler, 2013). This case is particularly interesting as the patient had a rapid progression of severe anemia and did not have any neuropsychiatric symptoms. In addition, it is rare to see patients progress to severe anemia with a vegetarian diet with occasional animal products.
Conclusions: Severe B12 deficiency without no neuropsychiatric symptoms and in the setting of minimal animal product consumption is rare but possible. Patients do not have to adhere to a strict vegan diet to experience rapid depletion of their B12 stores.