Thank you for the tip on the p5p. I think I will try it. My blood work also came out borderline deficient in iron. The nutrients more commonly cited in the literature for DAO production are B6, vitamin C, and copper. With my near-vegetarian diet it is likely I was deficient in both iron and B6 and last year and also had symptoms of B12 deficiency (it was horrible). I did stock up on B12 and thought that was the end of the story because it's hard to find information linking vegetarianism with B6 deficiency. I had not made the connection with not eating meat. Vegetarianism gets such glowing reviews I didn't think there was any issue with it.

Unfortunately, there are going to be a lot more people with this problem (they say histamine intolerance is "on the rise") because I did look up the single reference that gives the impression that there is no issue with B6 deficiency in vegetarians and it really just measures one point in time where it is likely all of the vegetarians in the study either supplemented with B6 or were careful and got it from other foods. That's because prior studies showed there was B6 deficiency with not eating meat. Now with everyone citing the new study (and not actually reading it) many people are just going to stop eating meat (like I did) and not worry about it. It really made me sick.

Hindsight is 20/20 and in retrospect this was pretty obvious. The timescales and symptoms all pointed to it. I had a number of things out in my blood work and other symptoms but not a single smoking gun that a physician could point to to make a diagnosis: My ALP was elevated, white blood cell count down, iron saturation low. It would have taken a bit of detective work and a doctor who had the time and inclination -and also believed me. Many doctors just dismissed my symptoms and were just checking the boxes: interpreting my blood work as if I did not have any. It was very frustrating and I know now what people with long covid go through.

I continue to recover and can eat most anything now (with the notable exception of Hollandaise Sauce 🙂 although I've not had the guts yet to try pickles or tomatoes. I need to give it some time. I still have nighttime symptoms but they are usually mild enough to be handled with a 12 hour Allegra.