Thyroid UK
82,797 members97,819 posts

Why would taking ferrous fumerate for 3 months and 100mg of thyroxine daily be highlighted to seek advice in the advisory notes?

Have lived with under active thyroid for 5 years and had 1 bout of anaemia in the past which was treated with solution ferrous fumerate . Recent bloods this year show I'm a little low in iron and again require treatment. How do I know what is 'a little low' what is normal levels I feel fine. My new Dr refuses to prescribe liquid solution and prescribed tablets which advise additional advice if taking thyroxine .will I feel unwell or have to increase my thyroxine. Am a little reluctant. Any similar experience would be appreciated for a better understanding.

6 Replies

The main thing with iron is to take it well away from any thyroid hormone replacement. So if you take your thyroxine at night, take your iron at breakfast, lunch and teatime and try to make sure there is a 4 hour gap between your last iron tablet and your thyroxine.

I hope that helps a little.

Iron is important for you body to be able to use the thyroxine (it appears) so, although you may not be currently experiencing symptoms, you may do if your iron continues to stay low.

Can you ask for the actually test results? Someone on here may be able to advise you better if they can see the numbers.

Carolyn x




Great minds... :D


The issue so far as I understand, is that taking any food or supplement which contains a significant amount of iron (other than heme iron such as liver), can prevent you absorbing the thyroxine.

Thyroxine binds tightly to iron substances (sulphate, gluconate, fumarate, etc.) and the complex that is formed passes straight through.

General advice is that you should separate taking iron from thyroxine by at least four hours either side.

You may care to read a blog on iron:

You only know what "a little low" is if you ask fro the results of the blood test - and the reference range. Strongly suggest you ask your GP/surgery.

Low iron levels are recognised as being closely related to thyroid hormone metabolism. It is important to have adequate levels in order to process the thyroxine you are taking.



Hi Depending on the cause Iron/ferritin usually for life. You should not have to but Spatone is best and you can buy it from Amazon. Results usually quite out ( especially iron) before GP treats. I would . first ask for a print out fro the receptionist, make sure it includes ranges. You should do this for any test, any where. Then yOU can compare the results etc Also ask for a repeat test in 3 months, GP may treat you then. After that annual.Thyroid makes sure you always have TSH, T4 and Free T3 done + ranges ,cost cutting again.

Best wishes,



Ferross in the form of tablets, can hurt he stomach of some patients. As the Admins have said it has to be kept away from thyroxine taken.

Some cant absorb iron in this tablet form. If you levels and ask for a printout, havent altered then your GP will have no choice but to prescribe what you orinally were on. ITs all about cost, tablets are cheaper on Drs pockets.

Iron is not only ferross, has your Dr checked the other B vitamins B12 for one too. That too is iron in another format. as folic.

Hypothyroiditis causes anaemia itself. But it always good Dr policy to find out why yours plummits. Typical is heavier periods or not eating enough iron enriched foods. Watercress being a good source, as in spinach.


You may also like...