My b12 was tested a few times and is 1500 down from 2000. Anyhow I still continued to take the b12 1000mcg and the b complex that I think has 250mcg. Anyhow I have had a lot of dizzy,spacy,so shaky,out of it feelings. I have been tested for everything possible and its not from meds I'm taking it seems. The dizzy comes and goes like it will be here for a few days super strong where I can't leave the house cause I feel I will pass out and then will go away for 5 days. I also get a tight feeling in my neck sometimes when this happens where I can't keep my head up. I asked my docs about the supplements and they all gave different answers if I should take it. So I stopped for the past 2 days to see. Any ideas if too much b12 could be causing this with already high levels in my blood? I feel so caught cause my pain I want to be helped but can't be feeling like I'm going to pass out.