
FYI: Just found out Folate and/or B12 deficiency can cause MCAS-type reactions + fatigue, etc
So I was watching a video - https://www.youtube.com/watch?v=-qrY9ANjujQ&t=1s
Where she talks about how both folate and b12 played a part in her MCAS-type reactions and fatigue. Once she addressed these (quite long-winded, worth a watch) she made a full recovery.
I believe the terms are pernicious anemia - https://my.clevelandclinic.org/health/diseases/22377-pernicious-anemia
And Cerebral Folate Deficiency - https://rarediseases.org/rare-diseases/cerebral-folate-deficiency/
I'm not saying it is - but it could be as simple as a b-vitamin issue. These aren't always quick to address as you may need specialist forms of the aforementioned type of b vitamins which she talks about in the video.
I'm going to give it a try because I've had good results from Thiamine supplementation but the evidence for folate and b12 issues is quite good for fatigue, breathlessness, neurological issues and even mcas.
You can read about histamine, the MTHFR link and mcas here - https://www.uhhospitals.org/blog/articles/2026/03/understanding-histamine-mthfr-mast-cell-activation-syndrome