u/Komancha

I posted this the other day https://www.reddit.com/r/LongCovidWarriors/comments/1ti4cu8/fyi_just_found_out_folate_andor_b12_deficiency/

And looking back and even now I cant believe I missed some signs - I'm almost certain now my ongoing fatigue, MCAS, histamine issues, breathlessness and neurological symptoms are B12 and Folate issues.

MTHFR, histamine and MCAS (in case anybody wonders how they are linked) - https://www.uhhospitals.org/blog/articles/2026/03/understanding-histamine-mthfr-mast-cell-activation-syndrome

Here are two pictures, one from a year ago during the onset of long COVID - and another just from today.

The first picture shows what I believe to be glossitis, a sign often associated with B12 deficiency - I assumed it was MCAS originally but now I realise after doing tons of research it may be linked to b vitamin issue.

https://ibb.co/PnQqHJJ

The second picture from today shows tongue ridging and scalloping which can be associated with B12 issues

https://ibb.co/Rkq4tsJh

I was so lucky to come across this video https://www.youtube.com/watch?v=-qrY9ANjujQ&t=2s - where she talks about long covid and eventually her B12 issue AKA pernicious anaemia and cerebral folate deficiency.

The issue with usual blood tests (especially in the UK) is that serum b12 levels can be high but you can still have problems with absorption so doctors often never get to the bottom of it because they are either unaware or wilfully ignorant but they can cause severe symptoms and even death eventually.

So as you can see from the tongue pictures, I clearly have some sort of ongoing issue what I believe to be B12 and folate. I started supplementing 3 days ago, and apart from a few startup effects im starting to feel incredible.

I will keep everybody updated.

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

My Long COVID may be a B12 deficiency and/or caused it

FYI: Just found out Folate and/or B12 deficiency can cause MCAS-type reactions + fatigue, etc