Get a blood test for serum vitamin B12
Ask for a complete blood count
Check mean corpuscular volume on the blood count
Test methylmalonic acid
Test homocysteine
Check folate level
Check iron studies if needed
Review symptoms such as fatigue, numbness, tingling, balance problems, memory issues, and sore tongue
Ask about risk factors such as vegan diet, stomach surgery, bowel disease, metformin use, or acid-reducing medicines
Consider intrinsic factor antibody testing
Consider parietal cell antibody testing
Follow up with a healthcare professional for interpretation of results