Health A-Z

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Symptoms tend to develop slowly and may not be recognized immediately. As the condition worsens, common symptoms include:

  • Weakness and fatigue

  • Light-headedness and dizziness

  • Palpitations and rapid heartbeat

  • Shortness of breath

  • A sore tongue that has a red, beefy appearance

  • Nausea or poor appetite

  • Weight loss

  • Diarrhea

  • Yellowish tinge to the skin and eyes

If low levels of B12 remain for a long time, the condition also can lead to irreversible damage to nerve cells, which can cause the following symptoms:

  • Numbness and tingling in the hands and feet

  • Difficulty walking

  • Muscle weakness

  • Irritability

  • Memory loss

  • Dementia

  • Depression

  • Psychosis

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From Health A-Z, Harvard Health Publications. Copyright 2007 by the President and Fellows of Harvard College. All rights reserved. Written permission is required to reproduce, in any manner, in whole or in part, the material contained herein. To make a reprint request, contact Harvard Health Publications. Used with permission of StayWell.

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