Thyroid UK
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What vitamins should you stay away from with underactive thyroid?

I was told not to take any vitamins from a chemist years ago with me taking thyroxine, so I have never bothered! Around 2 years I was told I need to have B12 injections every 3 months and now just been told I have to take iron tablets 3 times a confused, if I had known I could take vitamins etc I would have done this from day one of finding out I had an underactive thyroid!! Can anyone advise which vitamins to have and what dosage to take please? Then I can try to keep healthier at least. Thank you

5 Replies

Hi Tracy

I have to take iron as well, 210 mg three times a day, I was told by a endo not to take with Levo, to take at the opposite end of the day. So I take 125 mgs Levo before bed then take all three iron tablets together in one go in the morning! Hasn't done me any harm in the past two years! x


Hi Dylansmum, thank you for your reply. I have to take 210mg ferrous fumarate as well and I am on 100mgs of Levo. I have read on here about taking vitC with each tablet which can help to absorb it.


Just make sure you take them at least 4hours away from your levo and you can take anything, there is some advice on what to avoid in high doses on the thyroid uk website.


The thing is, if you had have been taking a multi vitamin both your B12 and iron deficiency could have been missed, or they may just have been in the NHS range and you would not have gotten help with them.

Taking vitamins without getting tested first just muddy's the waters and any bloods taken will not be giving the correct picture. My endo couldn't believe his luck when I told him I didn't take any vitamins, he then said "you wouldn't believe the amount of thyroid sufferers I meet who take countless supplements, which then leaves me unable to diagnose what is going on", so I would say that you were given good advice by the chemist.

Your iron needs to be taken with a good vitc supplement or your body will be unable to absorb it and needs to be taken with food to avoid it damaging the lining of your gut.

This is the vitc supplement I used and, although at first glance it looks expensive, it lasted me all through my 8 months of supplementing iron and I still have some left. You only need a small amount on the end of a teaspoon - which I then mixed in made up orange squash.

Your body is very finely tuned and taking supplements on a just in case basis can alter that balance and have all sorts of implications.

Moggie x


Hi Moggie, thank you for this reply, its much appreciated. x


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