Updated 03/12/13: P5P, a form of vitamin B6, seems to have solved a lot of this. See related link below.
My two migraine episodes were the usual tennis-ball-filled-almost-but-not-quite-to-bursting-with-boiling-oil-behind-your-right-eye kind of thing, caused by the old cliché MSG. The first culprit was a Chinese restaurant. The second, after I “got healthy,” was a package of sunflower seeds. All I’m saying is that never happened to me with Oreos.
Later I developed headaches, but not full-fledged migraines, from the amino acid L-glutamine, which I used to heal my celiac-ravaged lower intestine. Apparently this is a common reaction for people who also react to monosodium glutamate (MSG). The body can convert glutamine into the amino acid glutamate. It was still very helpful but I had to be careful how much I used.
As for run-of-the-mill headaches, I have only been bothered by them infrequently, and found them to be caused by:
- waaaaay too much vitamin A from supplements, which for a while led to headaches whenever I ate anything with high vitamin A, such as liver
- too much copper from ill-advised copper supplementation, also resulting in headaches when I ate copper-containing foods such as chocolate and liver
- vitamin B6 and iron supplements, until I corrected my vitamin B12 deficiency
- very low sodium levels, caused by dehydration on a hot day (two occasions)
- insufficient stomach acid, causing brief headaches whenever I ate anything
- vitamin D3 supplements, by lowering my thiamine (vitamin B1) and B6 levels too far.
- amino acid supplements, including 5-HTP — In the case of 5-HTP, this was due to its effect on B6. See last link.