nice report!
in regards of folic acid.. throw that into garbage.
not everyone tolerates the methylated folates... but there is another passive form called FOLINIC acid. note the INIC . so there is FOLIC and FOLINIC acid. the folINIC is the natural form. you can get it on iherb.
the problem with folic acid is that it is synthetic and a form which requires many conversation steps IN YOUR LIVER being dependent on a rare enzyme in your liver which not everyone has in enough quantities to process large amounts of folic acid. so what you describe definitely fits.
also cholin is good for liver health, maybe try phosphatidyllcholin or better egg YOLKS.
there is right now this TMAO theory from high choline supplementation. its not sure yet how things are, but natural foods do not pose a problem, and low dose supplements are mostly safe too.. so carnitin in like 250-500mg is for most not a problem, but 1-4g or beyond could be depending on your gut.
Thank you for your kind compliment. Please prep your mind, if you're tired, for a thorough response.
Also please keep in mind that every reaction I've had to anything was particular to the time I took it, so perhaps if you altered the order at which I took things, the effects wouldn't have been the same.
Thanks for calling to my attention folinic acid - I did not mention it, but, I've already tried it, and it too heightened the chest cramps! I don't think my body personally struggles with folic acid much but I thought for a while the same as you that that is the reason. I also speculated that the fact that folinic acid is often sold as half-and-half racemic version of the molecule - it is, and it's unnatural, much like folic acid - it therefore might be what was causing the chest pains, but I was either wrong or the choline corrected it anyway.
Pros worth - or not worth - mentioning of folic are that it is the cheapest and most ready to purchase, and can still work to rapidly restore folate levels if your body is born/evolved to work that way.
I would select either non-racemic folinic acid or like you suggest, 5-MTHF, but for the fact that I feel intervening something into a different stage of the metabolic cycle is not always equivalent. In my experience an extra conversion stage can be as much beneficial as detrimental - it is not so simple a matter as 'increase whatever populates the cycle and the cycle will take care of the rest'. I've noticed that the insertion points make a difference.
Perhaps this is also the reason some people respond to SAM-E more strongly than methionine - not because it removes the delay of an enzyme conversion, but rather that certain organs (brain and liver are possibly foremost relevant) have stronger affinity for it, or for some other reason.
Whatever the reason, I associate 5-MTHF more with brain/neural sensations, with folinic acid on the other side causing the strongest bodily reaction and perhaps upsetting my brain slightly.
I was more receptive at the time to choline bitartrate (the only chemical form I tried) over any amount of eggs I ate, like it targeted whatever the matter was more quickly, but it's possible I just needed more egg.