Thyroid UK
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What are the optimal vitamin & mineral levels?

Hi Everyone,

I've been hypothyroid for the last 3 years, and have been on T3/T4 combination treatment for the last 1.5 years - which has made considerable improvements to my overall health. There's still a few niggling problems (particularly some muscle/joint pain and stiffness and intermittent mild depression), so I decided to get my vitamin and mineral levels tested. Results are as follows:

IRON 22.49 umol/L (10.600 - 28.300)

T.I.B.C 51.29 umol/L (41.000 - 77.000)

TRANSFERRIN SAT 43.85 % (20.000 - 55.000)

FERRITIN 186.4 ug/L (30.000 - 400.000)

VITAMIN B12 319.9 pg/ml (191.000 - 663.000)

FOLATE (SERUM) 13.86 ug/L (4.600 - 18.700)

25 OH VITAMIN D *34.35 nmol/L (50.000 - 200.000)

Vitamin D is low, so I'll have to take supplements. Anyone any suggestions on the best supplements to take?

Also, do the other things look to be okay or sub-optimal?

My thyroid levels are:

TSH *0.008 mIU/L (0.270 - 4.200)

FT4 15.53 pmol/L (12.00 - 22.00)

FT3 5.76 pmol/L (3.10 - 6.80)

I'm currently taking 125mcg of T4 and 25mcg of T3 daily. T3 levels were previously just over 6 and T4 has also dropped slightly. Planning on seeing my endo shortly to ask for a slight increase in T4 to see if it improves my levels and gets rid of the coldness in my hands/feet which has been creeping in since the end of the summer.



14 Replies

Your B12 is also on the low side and supplement with B12 methylcobalamin sublingual. New advice is it should be 1,000 to prevent neurological damage.

Others will respond re Vitamin D and your other results and GP should prescribe Vit D. B12 and D are both prohormones so more than vitamins.

Have you had a recent blood test for your thyroid hormones? If not make a new appointment at the very earliest possible and fasting although you can drink water. Also leave about 24 hours between your last dose and the test and take afterwards.

Ask for a Full Thyroid Function Test, i.e. TSH, T4, T3, Free T4, and Free T3. Get a print-out with the ranges and post on a newquestion.

I think you might now need an increase in your hormones.

Post your results with the ranges on a new question.


Shaws, Thanks for the advice re the B12, but doesn't 1000 put it off the top of the reference range? Has this reference range changed recently?

Regarding the thyroid hormone levels, I got them tested a few days ago too (sorry, should have included this in my original post). I've edited my first post to include them.


Your thyroid levels are fine. Maybe a bit over medicated.


Marz is the one who best knows about B12 and D and I'm sure she will respond.

As I am a fan of T3 maybe a tiny dose increase will help your coldness as it is the only Active hormone which is required in our receptor cells. Of course, you also seem to be converting levo quite well as your FT3 is good. When T3 is added into the mix it does lower the T4.

When we feel well on a particular dose with no symptoms, that should be our optimum.

( am not medically qualified and have hypothyroidism - undiagnosed/untreated for a long time).

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Seen my endo today and am upping my T4 by 25mcg to 150mg. I seem to be converting well since I started the T3, so hopefully this should also improve my FT3 levels and get rid of my remaining hypo symptoms.


I do hope so as when symptoms are eased it's amazing how well you can be. Its when you are kept at a dose where you still have symptoms and they wont increase - even slightly - that problems can arise.


BarryWom - do not be concerned about B12 over range as anything your body does not metabolise will be excreted. Also it is advisable to have good levels as only 20% of your test result is available for the onward journey into the cells - where b12 is needed. Some people can survive on low levels of B12 it seems - but when Hypo it seems we benefit from optimal levels.

Do you have any symptoms of B12 Deficiency ? Scroll down in the link below ..

Read as much as you can of the above link to be well informed about B12.

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It's very individual, sometimes results can vary in connection with what have you eaten the day before tests, if you take any supplements, even if you have water retention... Sometimes it is very difficult to tell unless there is a severe deficiency present.


Didi2, I've taken no supplements for about a month + I fasted 14 hours as recommended, so hopefully the results should be fairly accurate. Wish I'd addressed the vitamin issues earlier, but I saw such vast improvements when I started taking T3 that I never really bothered looking. Think it's time to get the vitamin and mineral deficiencies sorted out though - hopefully they'll be easy to address and will prevent more health problems cropping up in the future!

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BarryWom Vit D is possibly best sourced yourself, you'll probably get a better quality supplement and your GP would probably give you too low a dose anyway. My Vit D was 17 and I didn't bother seeing my GP as I knew it would be a waste of time.

The recommended level of Vit D is 100-150nmol/L. As your level is 34.35 my suggestion would be to supplement 5000iu D3 daily for 3-4 months then re-test. If you have reached the recommended level then reduce to 5000iu alternate days as a maintenance dose.

When taking D3 we also need it's important co-factors K2-MK7 and magnesium. Vit D aids absorption of calcium from food and K2 directs the calcium to bones and teeth where it is needed rather than soft tissues and arteries where it causes problems. D3 and K2 are fat soluble so should be taken with the fattiest meal of the day. Magnesium is calming and best taken in the evening.

D3 comes in tablets and softgels so the choice is yours. My preference is softgels as there are few to no fillers and they come with fat added in the form of (usually) olive oil. You can get D3/K2 combos. This is the D3 I used and I was very happy with it. I now use a lower dose which is a combo supplement.

Different forms of magnesium can be seen here, have a look through and see which one would suit you best

Shaw's has mentioned B12, you could get Solgar or Jarrows sublingual methylcobalamin lozenges 5000mcg daily for 3 months then reduce to 1000mcg daily as a maintenance dose. Dissolve under the tongue for absorption directly into the bloodstream, don't chew or swallow as stomach acid destroys it. When taking B12 we also need a B Complex to balance the B vits and it's best to get one containing methylfolate which is natural rather than folic acid which is synthetic. B vits should be taken in the morning, no later than lunchtime, as they are stimulating.

Ferritin should be half way through it's range and you are almost there. You could maintain that by eating liver once every week or two.


SeasideSusie, Not sure if I'm that fussed on eating liver! But thanks for the recommendation for D2 and B12 supplements. I'm already taking Natural Calm magnesium citrate at night anyway - so that's one thing ticked off the list already (originally ordered to help improve sleep). Will retest in 3 months and see if my levels are improving.


BarryWom Probably a typo, but it's D3 you need :)


Yep, typo - I think D2 has to be converted to D3 with exposure to sunlight, which makes it pointless to take.


I don't know if you can get it in the UK (via Amazon?): I take Carlson Solar D Gems 4,000 IU vitamin D3 plus omega 3s (each capsule contains 500 mg of Norweigian cod liver oil which means I'm getting some vitamin A too). I take 32,000 to 36,000 IU ONCE per month as a bolus dose. I find it absorbs very well this way.

In your case, you'd need to boost your vitamin D level with similar doses every week for a month and then continue with what I'm doing. That should keep your blood level around 100 to 110.

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