Hello Steve! According to the protocol I currently follow (with a few added extras I think it needs), you would be depleting your B2 a lot by taking such a large amount of B1! B1 requires B2 to work, so you've likely made yourself B2 deficient and that's going to cause a lot of problems because B2 is essential to FMN/FAD formation, which is so important to the functioning of many enzyme reactions.
I only take B2 now. I began having issues with B6 toxicity (that was on a multi with 50 mg of most of the B vits). I use transdermal B12 oil.
As for oxalates, yep I can relate. I began having a lot of problems with oxalate dumping - guess what my favourite snack was? Dark chocolate! I still have problems with it now, even though I removed the highest ox foods. Apparently B2 is also connected to that as well, and histamine intolerance.
Well, my latest experiment is killing me! A couple of weeks a go I proved once again that methylated B9 and B12 caused muscle pain and stiffness so I stopped those. I waited the better part of a week and restarted Seeking Health B minus to see if I would have issues with it. BTW, B Minus has 20 mg of B2. Withstood a daily does of it for about a week and started noticing muscle pain again so I stopped.
Now the weird part. Several days after stopping the B Minus I was awoken in the middle of the night with upper back shoulder spasms like my whole upper back was trying to cramp up but couldn't. This subsided after about 15 minutes and I went back to sleep.
Saturday I was out helping a local charity cut and split firewood. After that session I had some usual back pain but this time it appeared to spread down my left leg between my waist and knee. Made it home limping. Sunday it was no better so I went to the local urgent care, took an x-ray and found no issues, diagnosed probably sciatica and sent me home with steroids and muscle relaxers.
The steroids and muscle relaxers haven't helped the pain much at all. My pain also doesn't really fit the classical sciatica profile. Standing for any length of time is excruciatingly painful while sitting is not; opposite of sciatica.
So now I am wondering if upper back cramping and now lower back/leg pain are possibly related and could be oxalate dumping. If it is it is the worst that I ever had.
I have also figured out that I have dysautonomia. Diagnosis of orthostatic intolerance, EOE, and aortic dilation. The confirming diagnosis is that the OI and EOE responds positively to the thiamine (TTFD) supplementation. That was another experiment that almost killed me due to a fall.