Hi, Vitamin B12 deficiency can certainly cause MS like symptoms, and it can, when extreme, cause nerve damage. It’s diagnosed, as you know, by blood tests. It is not dx through MRI or LP and does not cause MS, so no, sorry to say, you still have MS although having the Vit B12 deficiency treated might help your symptoms.
From what I can tell by internet sites (so I am certainly not an expert!) it can cause pernicious anaemia (or perhaps is the same thing… doesn’t seem clear) which is an auto immune condition, same as MS … so it seems more likely that having MS may have caused the problem with Vit B12 than other way round.
I have been tested for Vit B12 and am ok. I think what happens is that when we get MS symptoms we are tested for loads of other stuff (inc vit B12 and vit D) and therefore some people are at that point found deficient… but of course if we didn’t have MS symptoms we would never have been tested so it wouldn’t have been found. Must be millions of people who are deficient but never have reason to be tested. Does that make sense?
Sorry to dash your hopes of not having MS… I think with MRI and LP results, and obviously your symptoms, you will have to accept that it is MS.
Anyway, google it. There’s loads of info online.