A sore, red, swollen, or smooth-looking tongue can be a sign of vitamin B12 deficiency. Some people also notice mouth ulcers, burning sensations, or discomfort while eating.
The NIH Office of Dietary Supplements includes soreness of the mouth or tongue among possible symptoms of vitamin B12 deficiency.
Mouth symptoms can also come from infections, irritation, dental problems, folate deficiency, iron deficiency, or other nutritional issues. A doctor or dentist can help identify the cause.
8. Vision Changes
Vitamin B12 deficiency can sometimes affect vision because of its role in nerve health. Some people may notice blurred vision or other visual changes.
The NHS lists vision problems as one of the neurological complications that may happen with vitamin B12 deficiency.
Any new vision changes should be checked promptly, especially if they are sudden, worsening, or occur with weakness, headache, confusion, or speech trouble.
9. Shortness of Breath or Heart Palpitations
