Because B12 deficiency reduces healthy red blood cells, oxygen delivery to tissues becomes less efficient. This may cause dizziness, lightheadedness, or shortness of breath during normal activities such as climbing stairs or walking.
6. Mood Changes or Depression
Low vitamin B12 levels may also affect mental health. Some studies suggest that B12 plays a role in producing brain chemicals that regulate mood. People with low levels sometimes report irritability, mood swings, or symptoms of depression.
7. Smooth or Swollen Tongue
A swollen, inflamed, or unusually smooth tongue can be a sign of vitamin B12 deficiency. The small bumps on the tongue may disappear, making it look glossy or red. Some people also experience burning sensations or mouth discomfort.
8. Vision Problems
