A year of B12 supplementation, saw improvement, now getting worse
My onset of symptoms was tingling in my face. After an MRI came back normal they referred me to a neurologist and I started looking into potential causes, which led me here.
I started taking B12 injections every other day toward the end of July 2025. Things got worse before they got better as many have described here. At one point my symptoms pretty much vanished for a few months. Then at the start of 2026 I got a little spotty with my shots and started to feel the tingling in my face again (spotty meaning maybe 2x a week instead of 3-4x).
The neurologist said B6 toxicity and B12 deficiency can have the same symptoms so they tested me and B6 came back fine. They recommended I stay on the B12 shots at the every other day frequency and said it can take up to a year to recover.
I found out that I am MTHFR TT and started looking into what I might need to supplement to support methylation.
My current supplements are:
- 1mg hydroxycobalamin injection every other day
- Seed daily multivitamin (I took the jarrow mens multi most of 2025 but it was discontinued)
- 360mg of magnesium nightly (glycinate and threonate)
- 36.5mg thorne riboflavin daily (only started taking this after it was suggested to rescue methylation from MTHFR status)
- 1mg thorne methylfolate (started taking once I knew MTHFR status)
At the end of March I started taking the riboflavin and methylfolate and I feel much worse lately. Hands and feet are tingling, as is my face again. On an off throughout this process I have had hand and foot tingling but I am also taking an SSRI so there is a complicating factor. When I started the SSRI I got the tingling in my hands and feet but it eventually went away. I know it's suggested to not be on SSRIs, but it's going to take me a while to wean off and looking at the study cited in the FAQ it's more about SSRIs eating up some of the methylation capacity of the body rather than directly causing B12 deficiency.
Recent blood tests in 2026 aren't too concerning:
Homocysteine: 02/2024 - 14.6
07/2025 - 9.9
03/2026 - 7.2
05/2026 - 8.2
MMA: 05/2026 - 109
Potassium: 05/26 - 4.2
Serum Folate: 07/2025 - 8.9
05/2026 - 15.7
RBC Folate: 03/2026 - 597
05/2026 - 681
For iron, I've been tested nearly monthly this year and the ferritin values range from 85 - 50.
Based on the homocysteine it seems like methylation was under strain for some time and came back down (some of this may be attributed to SIBO during that time and nutrient malabsorption as a result). The homocysteine on 03/2026 was before I started supplementing methylfolate and riboflavin.
My vitamin D is in the 60s. I guess I'm not really sure what to look at. As far as I can tell I am giving my body what it needs but things seem to be getting worse. I did see some folks report that methylfolate made their symptoms worse so I was thinking of cutting that out for a few weeks to see if that improved anything.
Not entirely sure where to go from here or just stay the course, looking for suggestions if anyone has any ideas.
* Edited to include folate and iron labs.