Posted 9/22/2011 6:51 PM (GMT 0)
I think it is. I've been doing B12 shots for years, and while I don't remember, I'm sure I've hit a vein before. The bruising would seem to suggest you've got blood pooled under there, but the lump suggests that either the B12, or blood and B12 got in there too.
I've heard that B12 is safe in all but really huge IV doses. If you were doing the normal dose that I do, you should be OK. B12 just gets flushed out of the system. If you have access to an advice nurse phone number, you could call and get a second opinion.
Last time I had my B12 levels checked, it was in the 1500% range. GI didn't have a problem with that.