I took my first dose of Vitamin B complex yesterday in the morning, with my breakfast. I'm usually quite lethargic and by the afternoon I was very productive/energetic. My brain felt extremely switched on and strange. But I didn't feel especially on the edge of anxiety like I normally do, I had nervous type energy but I felt fairly happy/good about myself. So I felt really positive.

But during the evening, after dinner, I had a very sudden, very intense spike of panic. It scared the hell out of me because it was super strong and came out of nowhere. Usually I get 'warning' signs of anxiety like that and it creeps up on me, this was more like a shock to the chest and then I had all my usual symptoms of panic (racing heart, feelings of oncoming stomach upset, etc) but much worse than usual.

I managed to exercise to get rid of most of it, but the shakiness lingered and I felt on edge for the rest of the night and couldn't sleep. Today I decided not to take the Vitamin B complex, but I feel the same (anxiety all day, on the verge of severa panic attacks). So it's like me 'normally,' except a little worse, like me on a bad day.

Could this really be because of one dose of Vitamin B complex? It seems silly when I say it, because I only took it once, and I can't believe it affected me that quickly (both the positives and the negatives). Is that even possible, or would I need to take it for a longer period to see any effects at all? Has anyone else experienced such sudden side effects with it?

I don't know whether to just quit taking it because of how I feel currently/that incident yesterday. Maybe I should keep taking it and see whether I improve? If anyone has taken Vitamin B complex and felt worse (not the same) before they felt better I'd love to know, or any other advice you may have.

Thank you