Should I self supplement B12 and Folate? - Thyroid UK

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Should I self supplement B12 and Folate?


I'm relatively new here although have been reading some very good advice over the past couple of weeks.

I'm 22 and had a total thyroidectomy aged 15 after 4 years of treatment for hyperthyroidism was unsuccessful.

My thyroxine dose has always fluctuated around the 150mcg mark however after having my 100mcg tablet changed to TEVA a couple of months ago, all of my symptoms returned and I'm feeling very unwell at the moment with the usual symptoms.

One month ago I had a blood test with fair few tests on it as detailed below. Note I was on 125mcg at this time.

Free T4 - 14 pmol/L [9-20]

TSH - 5.84 miu/L [0.35-4.94]

Vitamin B12 - 211 ng/L [187-883]

Folate - 5 ng/ml [3.1-20]

Combined Vit D2 & D3 - 65.1nmol/L [50-220]

As soon as these results came through my dose was increased to 150mcg. I have felt so unwell however that I arranged an appointment today and he has further increased my dose to 175mcg and reinstated my Vit D tablets (1x800UI). Will retest in 6 weeks time with a T3 test also to ensure that I am converting well.

Whilst he didn't seem too clued up on optimum levels, he did seem to know about the availability of T3 and offered to refer me to a consultant who may be able to prescribe if I do not see any improvement in the coming months.

I'm aware that my B12 and Folate levels are towards the lower end of the range and am debating self supplementing, however I would like to see how the levels differ next time and perhaps have them prescribed by the doctor. He would not see the problem if I start to take them myself.

Any advice would be welcome as my current wellbeing has really given me the push to get on top of my thyroid health.


6 Replies

Kieran, there is a very big clue here

"however after having my 100mcg tablet changed to TEVA a couple of months ago, all of my symptoms returned and I'm feeling very unwell at the moment with the usual symptoms."

Quite a few members have found they don't get on at all well with Teva brand. Tell your GP how you have deteriorated since being on Teva and ask if you can go back on your previous brand, or if your surgery doesn't name brands on the prescription then ask your pharmacy to source your previous brand for you, or ring round other pharmacies to see who can dispense the other brand.


As for self supplementing with B12 and folate, I think it would be preferable to point out the low levels to your GP and see if he will do something. Check for signs and symptoms of B12 Deficiency here first and mention any to your GP.

You could pop over to the Pernicious Anaemia Society forum here on Health Unlocked for further advice


800iu D3 isn't going to do much to raise your Vit D level, it's not even a maintenance dose. The recommended level is 100-150nmol/L according to the Vit D Council, and you need more like 2000-3000iu daily at the moment, then when you've reached the recommended level find your maintenance dose to keep it there, and that may be 1000-2000iu daily.

When taking D3 there are important cofactors needed

D3 aids absorption of calcium from food and K2-MK7 directs the calcium to bones and teeth where it is needed and away from arteries and soft tissues where it can be deposited and cause problems.

D3 and K2 are fat soluble so should be taken with the fattiest meal of the day, D3 four hours away from thyroid meds.

Magnesium comes in different forms, check to see which would suit you best and as it's calming it's best taken in the evening four hours away from thyroid meds

Check out the other cofactors too.


Was ferritin tested? That's very important and needs to be at least 70 for thyroid hormone to work and T4 to T3 conversion to take place.

Thanks for your reply Susie. I did mean to mention that my pharmacist seemed more knowledgeable than my doctor and has put a note to avoid Teva, all of my tablets are Mercury Pharma now so will see what difference that makes over the coming weeks.

As for my vitamins that's helpful advice, what I will do is book an appointment next month once I've had a good read up on everything and get over that next hurdle. Ferritin wasn't tested for some reason so I will be sure to get that included also.


If you don't like Teva tell your pharmacist you need to go back on the make you were previously taking. Not all brands suit all hypothyroid patients and I've seen a number of complaints from people feeling unwell taking Teva.

VitD is optimal around 100. 800iu is insufficient to raise levels. I would buy 5,000iu D3 and supplement for 6 weeks and then reduce to 5,000iu alternate days and retest 3-4 months later. VitD should be taken 4 hours away from Levothyroxine.

B12 and folate are low. If you have symptoms in go to for advice before supplementing. NHS won't prescribe when levels are within range unless you have pernicious anaemia and then you will be prescribed injections at 2-3 monthly intervals.

fordefocus in reply to Clutter

Thanks clutter, as I've said to SeasideSusie I've had Teva swapped and now I think my next hurdle will be these vitamin levels, I will see how the next month goes regarding my thyroid levels and in 6 weeks at my next bloods book in and state my case.

Clutter in reply to fordefocus


It's really not difficult to improve vitamin levels if you dose appropriately.

Would be helpful if you could fill out a yellow card to say you had problems with TEVA. if it is notified then if an excessive amount had problem it will be looked into. You can fill it in online.

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