I found out it was calcium itself when I noticed the symptoms happening whenever I took a pure calcium supplement. I then noticed I felt better when I stopped and avoided foods high in calcium altogether. I never take calcium supplements, it's not from that.
These symptoms happen even when I take almonds.
I bought a high quality multi-vitamin from EOR hoping that I wouldn't get a reaction from the calcium in it, but unfortunately I did. The only multi-vitamin I can take is one from the health food store that doesn't have any calcium in it. I've run out a while ago though and dunno if they'll still have it.