mrs D, I was wondering if you could help me please.

I have been taking sublingual b12 (cyano) for about a month now, because of tingling in my arms, not being able to stand up straight, weakness and pain in the arms, back pain (I couldn't even wear a bra), and the tingling went away in 3 days, and I gradually got better, so I know my problem is a B12 deficiency (my number was 270 about 6 weeks ago) but during that time I've also had days where I would feel faint, dizzy, and my heart beating really fast - aka symptoms of hypokalemia.

I've also had 2 injections of 1ml/1mg of hydro B12 in the past few weeks, but I've since stopped taking all B12 and put a halt on the injections for now because I wasn't sure what was causing the dizziness. Before starting the B12 my arms felt weak, but at least I could think properly. But these new symptoms are scaring me.

I've had an MRI of my brain and spine and MS was discounted (no lesions), but do you think I might still have MS even if the brain scan was negative? The symptoms seem to get worse during hot whether, or after I've had a shower (I feel faint).

Why would I get these symptoms after starting B12?

Am I having a reaction to B12?

Could I have low pottasium which is causing the mental issues?

Or could my body be adjusting to suddenly having B12 after being deprived for so long?

Does taking B12 mess with blood glucose levels?

Do you think I could also have pernicious anemia (my ferritin is 10).

I also have a thread in the vitamins & supplements section if you want to read it.

Thank you so much.