Thyroid UK

Confused, does anyone know much about B12???

Hi All,

In Decemberi had a Blue Horizon thyroid blood test. One of the things highlighted was low B12. My results showed the following:

B12 226 (deficient <140, insufficient 140-250)

Tsh 2.11 (0.27-4.20)

FT4 9.65 (12-22)

FT3 4.35 (3.1-6.8)

Ferritin 59.5 (20-150)

Folate 9.77 (8.83-60.8)

The doctors interpretation which comes along with it explained that B12 was insufficient and that some experts believe that 400-500 is ideal for b12 and that below this can lead to symptoms and pernicious anaemia. My endo has the results and was going to recommend that my gp give me b12 injections. I explained this to my gp who sent me for further tests to check for PA. I went to the dr yesterday (different from before) and she said everything was fine, no PA, thyroid was ok, basically my body is happy. I disagree when I keep getting pins and needles in my left hand and foot and have to sleep for one whole day each week not to mention my ridged disintegrating nails, weight gain, poor memory and breath shortness... anyway, the results from their tests are as follows (nature throid dose has increased):

Tsh 0.03 (0.4-4.9) < she said she wasn't worried on account of the natural thyroid supplements

T4 11.9 (9.00-19.00)

T3 5.2 (2.6-5.7)

B12 286 (187-883)

Folate 3.4 (3.10-20.5).

I definitely feel a bit better since the increase of nature throid but I can't believe that everything's normal when I'm having to crab walk down the stairs each day and the other problems persist. I don't know if it's related but I keep getting floaters in my right eye which is really annoying. Any way, any help would be gratefully received. I think I'm particularly concerned with the B12 because it's only just outside the insufficient range and from the doctor's notes it should ideally be higher than that.... I feel very frustrated 🙄

6 Replies

Hi hellybaybee

You are right it is all very frustrating, you would think GPs would be more supportive. Without the advice on this forum I would have not known where to start.

My B12 was 187 Sept last year, my GP tested and said everything was fine and would not be offering injections. Since Sept I have been supplementing with B12 5000mcg Solgar lozenges. My last test showed my B12 had increased to 998. Migraines are now very infrequent, still occasionally have restless legs. Nails are ridged but thought that might be something to do with the thyroid, I also have floaters.

I hope my cells are taking up the B12 and may next do the B12 active test in an effort to find out. I also joined and had a nice email from Dr Chandy saying that they would be able to advise if I decided to self inject.

Good luck on your journey

1 like

Thank you for this, it's really really helpful... I will take a look at that site you have recommended


rosw and hellybaybee - please be aware that you can get lots of advice on B12 on the PASoc Forum.

Ideally you should exhaust all possibilities of getting a diagnosis of B12 deficiency before supplementing as supplementing makes any further testing really difficult.

hellybaybee - your B12 results are cetainly in the grey range where people can show up as being 'normal range' but are actually deficient - this is because people vary a lot in the amounts of B12 they need - but unfortunately most GPs aren't aware that they need to look at symptoms because of the flaws in the B12 serum test.

The difference in levels between the two tests is actually in the noise range for the accuracy of the test.


Thanks... she didn't really ask about symptoms she just reviewed the test... I get annoyed with myself because I find it hard to challenge them because I have become so used to them just fobbing me off... they seem quite nice in my current practice... not the shrug I used to get from my last doctor... I might bring it up with my endo when I see her in march... she was going to send a letter but her secretary isn't always on the ball so I don't think that happened.


Just a quick update, finally got my methylcobalamin yesterday... my mom (who was briefly a nurse) came round to help me inject... I can't believe it but I think it's working already! I can't really explain it but I feel a little more energetic and happy... I know it's just the first dose but I felt like this when I was first medicated for hypothyroidism- I wanted to do laps! Lol thanks for the recommendation!

1 like

Pleased you are feeling better.

I have just had the active B12 test in an effort to see how my body is taking it up. All quite difficult to understand.


You may also like...