A 47-year-old woman with a 5-year history of psychosis treated with olanzapine, accompanied by her mother, sought medical advice for fatigue and dyspnea of progressive onset lasting for 4 months. On physical examination, the patient was pale with pitting edema of lower extremities. Her speech was reduced, her attention and concentration impaired, and she reported visual hallucinations. She declined to answer questions and to participate in a mini-mental test evaluation. No lymphadenopathy or hepatosplenomegaly were palpable. Neurologic examination was unremarkable. The blood cell count showed a hemoglobin level of 4.0 g/dL (mean corpuscular volume 112 fL, reticulocyte cell count 58,000/mm3) and a platelet count of 110,000/mm3, a normal white blood cell count but hypersegmented neutrophils on blood marrow smear. The lactate dehydrogenase level was 2,418 IU/L (normal <250), total bilirubin 23 μmol/l (normal <17), and haptoglobin <0.08 g/L (normal <0.55). Vitamin B12 blood level was<83 pm/L (normal >187pmol/L) and serum homocysteine 80.8 μmol/L (normal <15). Thyroid-stimulating hormone level was normal. Direct Coombs test was negative. A bone marrow smear demonstrated erythroid hyperplasia with megaloblastic maturation, hypersegmented neutrophils, and megaloblasts consistent with vitamin B12 deficiency. Upper gastrointestinal endoscopy with gastric biopsies was normal, and serum parietal cell antibodies were not detected. Search for a medical cause of confusion including brain computed tomography (CT) scan and electroencephalogram was negative. Diagnosis of vitamin B12-deficiency anemia with psychotic disorder was established. Finally her mother revealed that the patient was following a strict vegan diet for 7 years. Oral supplementation at the dose of 1,000 μg vitamin B12 (cyanocobalamin) daily during 10 days then every 10 days led to normalization of blood abnormalities within 3 months. Six months later her psychiatric symptoms had relieved with control of delirious and negative behavior and a mini-mental test evaluation of 30/30. The patient was then lost to follow-up.
We report here a case of severe anemia and psychotic syndrome related to vitamin B12 deficiency in a patient who followed a vegan diet. Vitamin B12 (or colabamine) is a water-soluble vitamin playing a key role in DNA synthesis, mainly absorbed in the terminal ileum after binding to intrinsic factor, and stored in liver.1 Natural sources of vitamin B12 include meat, fish, dairy products, and eggs. Vitamin B12 deficiency is observed in about 2% to 26% of the general population, depending on the definition used.1 Severe deficiency is related to severe malabsorption including pernicious anemia, total or partial gastrectomy, ileal resection, and inherited metabolic diseases, and mild to moderate deficiency is usually associated with nonimmune chronic atrophic gastritis and drugs (proton pump inhibitor and metformin).1 Vitamin B12 deficiency can be responsible for megaloblastic anemia or demyelinating neurologic disease1 and also psychiatric symptoms in 5% of patients, including depression, bipolar disorders, psychosis, and dementia, sometimes in the absence of anemia.2
In western countries dietary deficiency is reported mainly in elderly and vegetarians with limited intake of meat products, but especially in vegans avoiding all animal foods (and breastfeeding infants of mothers with vitamin B12 deficiency) and affected 86% and 69% in strict and moderate vegans, respectively.3, 4 The deficiency develops after several years of depletion because of liver stocks, but severe anemia and psychiatric symptoms are unusual. Sublingual or oral supplementation is mandatory and effective for vegans.3, 4 However many patients are reluctant to use supplements.
Physicians should be aware of veganism as a cause of vitamin B12 deficiency with possible severe anemia and psychiatric symptoms.
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-Claude Bachmeyer, MDa, Rim Bourguiba, MDa, Vasiliki Gkalea, MDb, Loula Papageorgiou, MDb
