The major symptoms felt are shortness of breath, fatigue, pallor and rapid heart rate. Gastrointestinal problems like diarrhea and loss of appetite are seen. A tingling and numbness of hands and feet or paresthesias, along with a sore mouth are some more symptoms. An unsteady gait, especially in the dark and slowing of mental processes are some additional symptoms that may be associated with this disease. Sometimes there are tongue problems and impaired smell.