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Thyroid UK
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Help please, T3 and B12 deficiency especially?

Please could you give me some advice and guidance? I'd especially like to know about B12 and if I reduce my dose of Levothyroxine, will T3 go up or down? I still have very little energy, do I perhaps not convert T4 to T3 properly? Or does it look as if I just need to get the ferritin up to around 300?

(I'm on 75 mcg of Levo weekdays, 50 mcg at weekends).

Latest results Feb 2016 are:

T4 18.3 (range 10 - 24.5)

T3 3.9 (range 3.8 - 6.7), "normal"

TSH 0.07 "slightly suppressed". (Range I think is 0.05 - 5 or 7)

Ferritin 15 (range 12 - 300)

Ferritin has risen to 34.

In December 2015:

B12 = 438 (range 180 - 1000), being vegan I supplement though stopped before the test

Vitamin D 50.9 (range over 30-40)

Folate 20+ (range 4+)

Calcium 2.26 ("good")

Inflammation "none"

History is that I became hypothyroid between the ages of 12 and 15 though unrecognised until I was about 45, once diagnosed GP easily traced it back from symptoms.

My results go up and down more than I can show for lack of test results, but if you would please look at Jan 2014 to June 15 you'll see what happens, and I don't feel much different on Levothyroxine. Still suffer from weakness, fatigue (diagnosed as CFS but I don't think so), low mood, low energy, always cold, very poor memory and general brain function and more of the usual symptoms though oddly the reverse of constipation even while taking prescribed iron.

Previous results though I'm sorry I only have 'normal' sometimes and no ranges, I didn't know the value of figures until coming onto this site.


"TFT down to 6.8" guess this means TSH

Before 2011

"TFT 7.3" I guess this meant TSH

Feb 2011

"TFT 9.1" - LATER told "TFT 1.9" so I guess this meant TSH 1.9

B12 "high"

April 2011

"TFT 1.5"

D3 at bottom of range

Nov/Dec 2011

TFTs all "normal" (on Levo)

B12 868

Jan/Feb 2014

T4 21.1 (range 10 - 24.5 I presume)

TSH less than 0.05

GP recommended pregesterone, which does seem to help.

October 2014 (apparently the GP wrote in my notes she though I was not taking the Levo!)

TSH 15.9

June 2015

TSH 1.0

August 2015

TSH 2.7

I long to feel well enough to function enough to socialise just a little and enjoy my son and his new baby visiting, I don't 'live' I just exist, much like an animal: "wash, work, eat, sleep".

Thank-you for sharing your knowledge and experience.

17 Replies

Supplementing B12 will be reflected in your result - even though you stopped. It can remain in the body for months I have been told. Your FT4 result is not too bad but you seem to have a conversion problem. This could be due to LOW B12 - Folate - Ferritin. They all need to be optimal for you to convert well.

I cannot see any results for thyroid anti-bodies - if they are present then that may explain the fluctuating TSH. They are called Anti-TPO and Anti-Tg. Could it be you have Hashimotos ? This may also be the reason for low vits and minerals and a conversion issue.

Your VitD is also on the floor - and needs to be increased.

Your B12 needs to be around 1000 to prevent cognitive decline and over 500 to prevent neurological issues. If you are not able to imporve your levels of B12 - Folate - Ferritin and VitD - then maybe introducing some T3 to the mix would help.


Thank-you Marz very much, I was hoping you'd reply because I've seen how much you understand B12 but I didn't expect such a quick reply!

I presume then that my B12 result could be misleading and now that I think of it I continued eating foods with added B12 before the test.

I don't know why the B12 is low, I am careful with this because it's not available in my vegan diet.

I'm taking 1000 ug sublingual B12 (cyanacobalamin), is this the right thing or would you recommend something else or a different dose?

Following one of your replies to someone else with a link to a site about B12 I noticed that I have almost every symptom of deficiency.

My GP said I have no conversion problem, that the T3 result is good, is she mistaken? Do my results suggest otherwise?

I had one antibody test and it came back, I've forgotten the exact wording, but 'not positive', though a family friend had three negatives before her definite Hashimoto's was found. The GPs are very fed up of me and have me down as a hypochondriac so I haven't asked for another test.

Thanks for telling me about the Vitamin D, since the range is over 30-40 I thought 50.9 was good! I've bought a higher supplement, 1,000 iu, an increase from 7500.

I'll keep going with these supplements and hope to feel a difference in a few months.

Again, thank-you Marz very much indeed.

Are you basking in lovely temperate weather?


Your Doc is wrong I am afraid. You can see you are at the bottom of the range in the FT3 - it needs to be higher - so I would suggest you are not converting - due to the above reasons - possibly ?

The B12 in your blood test is ONLY a guideline as ONLY 20% of that result is available to be utilised at a cellular level. Both bound and unbound B12 molecules are in the blood and only the bound ( or is it the unbound ? ) can reach the cells :-)

It would be better to take Methylcobalamin - cyanacobalamin is cheaper but has to convert in the body. I would go for the Jarrow 5000mcg B12 lozenge - available on Amazon. Keep under the tongue until dissolved. There are also sprays available - again for use under the tongue - to avoid gut issues. Do not forget you will also need a GOOD B complex to keep all the B's in balance. You cannot overdose on B12 as it is water soluble and any amount not required will be excreted.

Could you have your tests done privately through Thyroid UK ?


The above link shows you how to dose D3 according to your results. Am suspecting your results will be measured in nmol/L - so to convert to ng/L - you divide your D by 2.5. So you can see your is low. There is also a chart on the same website indicating levels of D required to prevent certain serious illnesses......

There seems to be a small amount of people who have problems with VitD - so start low and slow and see how you go. I take loads and according to some websites/people I shouldn't be taking so much - but without it I notice the difference !

What your Doctor does not know about B12 will harm you - I should know as I underwent serious spinal surgery for stenosis. Now looking at the MRI scans I can see it was de-myelination of the spinal cord due to a VERY LOW B12 - around the 300 mark for many years. The Terminal Ileum was removed when I was 27 - I am now 69 - and the surgery was in 2007 - before I learned about B12. Most of our B12 is processed in the Terminal Ileum and sent back to the liver.

So I focus on the things I can do - rather than the things I cannot. Just taken a yoga class this morning for 6 - and yes the sun is shining :-)

You are not a Hypochondriac - you are seeking wellness ....


Hi marz, can you tell me more about the terminal ileum please or direct me to the information. I have problems with my spine and liver so this is interesting. My b12 at 275 is also very low and started the sublingual b12 last week. Am Feeling a little better already. Maybe a coincidence? Thank you :-)


The Terminal Ileum is where the small intestine ends and the large intestine begins. The latter starts after the ileo-caecal valve - which I do not have. I had ileo-caecal TB.

Some people do respond quickly to B12 - good to hear ! Hope you are also taking a GOOD B Complex to keep all the B's in balance.



Thank you. I do wonder if I too have damage on the myelin sheaf. Thanks for the information. :-)



Watch the third video down and then you will understand how important B12 is ....


Hello again Marz, reading about the terminal ileum processing B12, I remember about 20 years ago my GP telling me the pain I was experiencing was my caecum going into spasm (a result of bad infection through womb tubes etc).

I still have pain in the area, do you think there might be some connection?


Quite possibly. People with Crohns/IBS/Diverticulitis/Colitis all have absorption issues with B12. So if the infection you had involved the Terminal Ileum as well as the caecum then it could be scarrred and not working efficiently. Maybe a colonoscopy would reveal something.


Third video down shows the poorly Doc with B12 deficiency....


The film is very touching, I think you put it on here before, someone did, it's one you don't forget.

I think you might have put me on the right track, I still frequently have pain in the lower right side of my abdomen.


Thank-you again Marz. Hope it doesn't sound slushy but you are inspirational, I've read before the journey you have had and yet all your posts are upbeat and uplifting.

Yes, after April I could have private tests

Thanks for the explanation about vitamin D, I'll go to the site.

You might be interested in this if you don't know it already. One of my students has one of those watch-things that measures calories and at the end of the yoga class told me she had used around 350 calories, and that was a Beginners group, which is comparatively easy. I was surprised we burn off that many.

Our sun has gone now but I'm going to iron out in the conservatory - out there I can pretend I'm in warmer climes!

Cheerio kind Marz


Wow that is great news :-) I take two classes a week - sometimes three - so that should balance out my wine rations :-)

Glad my posts come across as upbeat. Sometimes I am a bit bossy too when I am tired and keep reading the same old same old about Docs and how they let patients down. Also I am cross when people come onto the forum asking a question - lots of people give amazingly helpful answers only for the poster to say they will discuss it with their Doc - SCREAM !! OK I know - it is a journey and some of us go faster than others !! Sadly most of us who have found wellness have had to go it alone - with the knowledge gained from others who know more :-)

Ironing - :-(

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Yes indeed to the wine balance - the balance we always seek :)

When posters write that they are going to discuss something with their doc I always think that means they have appreciated the advice and are going to take it further. Maybe that reflects a somewhat naive faith in the doctors!

Ironing for me is relaxation, as if I smooth out my troubles while listening to something good on radio 4: plays or Inside Science.

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Please don't raise your ferritin to 300. If you get it up to 80 - 100 you should feel better. The Iron Disorders Institute is suggesting that the range should stop at 150, and WHO thinks the same.


Thank-you Aspmama for this advice, I will see how I feel around 80 - 100, I really appreciate you alerting me to this.

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Sorry I should have mentioned that most people here suggest Ferritin to be good at around 80/90. Aspmama is right....


Thanks, I'll be careful, you've been so kind.

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