Breathlessness and Dizziness
If you become anemic due to a B12 deficiency, you may feel short of breath and a bit dizzy, especially when you exert yourself.
This is because your body lacks the red blood cells it needs to get enough oxygen to your body’s cells.
However, these symptoms can have many causes, so if you notice that you are unusually breathless, you should speak to your doctor to investigate the cause.