What to do? b12 supplements or not?: Current test... - Thyroid UK

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What to do? b12 supplements or not?

Laundretta profile image

Current test results in my profile for ref.

So on the thyroid front I have an appointment with a thyroidy nhs endo in 3 weeks time. GP scared stiff of giving me a stroke so won't let tsh drop under 2, but I only want a bit more levo, so I'm hoping the endo isn't a total tool and plays the game. As a back up plan, hubby is under instructions to go levo buying while he's in Spain next week.

A year ago when my tsh was 2 for a while, (it's been up as far as 6.6 when on 75 mcg levo and down again to 2 since with dose increase to 100mcg) At tsh 2 last year I felt not 100% at all, but much better than I do now. I've not been well at all over the last 4 weeks or so. Worse than pre-diagnosis. Having got the 'surprise' low active b12 result back a month ago, I put it to my GP that this might be the reason.

His reply was that I don't have a high MCV, so that couldn't possibly be the case. and anyway, why would I think that 35 was low for active b12? Brain fog prevented me from remembering during the discussion that MCV hasn't been tested for 18 months. And then I gave him something to read about active b12 tests. He basically thinks I'm a hypochondriac, so occasionally humours me...

Of course, NHS won't test MMA (or is this just my GP?) and he basically disregarded the modern, accurate highly regarded Active b12 test, and sent off for total b12. He agreed to test anti-intrinsic factor Ab while he was at it.

Total b12 came back low but in range.

Negative for antibodies, but not the most reliable of tests. Good for confirmation if it comes back positive, but not much use otherwise. Could be atrophy due only to undertreated hashi's.

Meanwhile, I still feel like someone has removed the top of my skull and replaced brain with a jobby.

So I'm not sure what to do next. I sure I'm taking enough b12 in through diet alone, ergo there must be an absorbtion problem. Problem is, if I start self medicating, I'll be stuck with that as that will skew any future tests.

Option 1. Do nothing, see if it gets worse, get retested at some point. I only have symptoms that could also 'just' be hashi's at present.

Option 2. Pay to get MMA tested myself. If deficiency indicated, hope that GP will give injections.

Option 3. Start supplementation either injecting or those dermal patches.

Any other bright ideas or experience from the floor?


10 Replies


I assure you that you are not taking enough B12 from diet. We can discuss all this.

Read this website: b12-vitamin.com

Hope it helps.

Laundretta profile image
Laundretta in reply to CESA

Why might I not be getting enough b12 in my diet? I eat plenty of eggs and red meat. Thanks for the website link though, interesting read.

SlowDragon profile image

Low vitamin B12 and low folate are both common when under medicated for hypothyroid

Full private testing here


Using test of Homocysteine levels to check for low b12


Good explanation on homocysteine


Oral may be as good as injections


B12 generally


Do you have symptoms of low B12 ? Eg pins and needles?


Low stomach acid is common hypo issue and leads to low vitamins

Many on here self supplement using sublingual B12 lozenges or B12 mouth spray

Plus usually recommended to supplement a daily good quality vitamin B complex too. One with folate in not folic acid

How's your vitamin D and ferritin levels?

Hi slowdragon

Numbers and supplements details are on my profile but my vit d and ferritin okay. Just. I have started supplementing vit d as you suggested a month ago.

I was concerned about self supplementing b12 if it really needed injections to bring it up as you suggested last month too as the active b12 was only 35.

I’m not sure about symptoms. The ones that dovetail with hashis - brain fog, low mood, achy legs are worse than when my TSH was at 2 last year. I’ve had a constant dull headache for a month, weird tinnitus/feeling in my ears. Hand grip is weaker ( struggle to hold the petrol pump for example) eyes seem a bit blurry. Bit dizzy occasionally. These are all new. But no tingling.

I think I might just get MMA/homocysteine levels done privately then at least I know where I am. Might have one last try at the GP and tell them I plan to self supplement.

I’m getting my knickers in a right knot about it to be honest.

Laundrette, I’m following! I have just asked for advice on the PA forum too as no one bar me seems bothered by my v low but “in range” B12, despite having exactly what you mention above.

On a side note, I saw Dr Toft today and annoyed that my brain fog meant I forgot to ask about it!

You have the same symptoms? I'd started to think I was imagining things, so that feels good to know. :-)

If I get thyroid levels right might the stomach acid come back?

SlowDragon profile image
SlowDragonAdministrator in reply to Laundretta

Yes it should do.

Ok, this is great news! As I'm not overtly PA, I'll dose up the b12 (got me some transdermal patches 5000mcg a go- 1/week) and got the Thorne Basic B complex you recommended. I've been waiting for a conclusion on the b12 'issue' before taking them.

Apologies SlowDragon, it was SeasideSusie with all the lovely vitamin advice last month. You two rock.

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