Yes I am familiar with that from personal experience. Also iron deficiency can cause that too which I am also experienced with.

There are many other symptoms associated with that though so one wouldn't just get shortness of breath. The other symptoms mimic many MS symptoms so if one has MS they may have a B12 deficiency and not notice symptoms until shortness of breath happens.

A blood panel for that would clear up any issues of that.

I have Pernicious Anemia by the way and have had several MS type symptoms for a couple of years now. I am healing and getting my nerves back but as the doctor said nerves heal at about a millimeter a day or less and some are 2 feet long.

I still have some tingling in my left wrist and heat sensations on my left side like the leg, thigh and chest and back. The tingling in the face is gone as are the numbness and tingling in my feet. I actually have my tickle sensations back now. I still have muscle fatigue in my left arm sometimes, spasms on the arms, neck and calves under the skin but they are not occuring as often now except for the calves virtually all the time. I can balance on one leg now finally as the muscles are getting their mojo back little by little.

I know I have some permanent damage but caught this in time at least.

But enough about me I just mentioned it because I know about the B12 and what it can do to your body if you do not get any.

Then with Iron deficiency you get everything from fatigue to chest pain because your heart doesn't have enough oxygen as well as organ damage.

I mean this is serious stuff so if one has shortness of breath get checked right away. Go to an emergency room and they can at least do some blood work and check some other stuff out.

Many things cause a shortness of breath.