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Thyroid UK
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Low ferritin on levothyroxine

Hi I am new I have had low ferritin since 2012 and my periods are heavy. They have been heavy since I started them properly at 13 (now 31) why could this be please? Also getting an increase in blood rushes when on periods and the blood rushes continue when I am up and walking around. My dark circles look even darker than they do when I am not menstruating as well. I take levothyroxine for hypothyroid diagnosed in 2011 but have been told my levels are normal so it can't be my thyroid. Thank you

FERRITIN 17 (30 - 400)

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First thing is do you have any actual blood test results? If not you need to get hold of them. You are entitled under data protection laws.

You may be able to view test results online - ring and ask about this. If you can then apply for online access to your account. All GP practices are supposed to offer this, in reality very few have blood test results available online.

If not then ask for print out of recent tests. Pick up in a day or two. They may make a nominal charge for paper.

You need to know results for TSH, FT4 and FT3.

Do you also have high thyroid antibodies? You need to know. Did GP test these? If not ask that they are tested.

If antibodies are high this is Hashimoto's, (also known as autoimmune thyroid disease). About 90% of hypothyroidism in UK is due to Hashimoto's.

Hashimoto's very often affects the gut, leading to low stomach acid, low vitamin levels and leaky gut.

Low vitamins that affect thyroid are vitamin D, folate, ferritin and B12.

Important to ALL test these.

If they are too low they stop Thyroid hormones working.

Have all these been tested, not just ferritin

if not ask that they are. Always get actual results and ranges.

SeasideSusie has full advice on how to increase ferritin

Low ferritin is symptom of being under medicated.

50mcg dose is low starter level. Presumably you had retest 6-8 weeks after starting in 2011. Increased in 25mcg doses until TSH is around 1 or under.

All thyroid tests should be done as early as possible in morning and fasting and if taking Levo don't take it in the 24 hours prior to test, delay and take straight after. This gives highest TSH


Hi I have been told my thyroid results are normal and I take 50mcg levothyroxine since diagnosis in 2011. I will post these now.


Thyroid peroxidase antibodies 278.5 (<34)

Thyroglobulin antibodies 341.3 (<115)


So your antibodies are high - this is Hashimoto's, (also known as autoimmune thyroid disease). About 90% of hypothyroidism in UK is due to Hashimoto's.

Hashimoto's very often affects the gut, leading to low stomach acid, low vitamin levels and leaky gut

If they are too low they stop Thyroid hormones working. Then tests appear "normal " but you remain hypo

Essential to get these results and supplement if low (very likely) to correct low levels

As you have Hashimoto's then hidden food intolerances may be causing issues, most common by far is gluten. Changing to a strictly gluten free diet may help reduce symptoms. Very, very many of us here find it really helps and can slowly lower antibodies.







The thyroid results are in another post. I wrote out my vitamin and mineral levels in this one. Thanks


Saralou9 Go back to your doctor and tell him that as your Ferritin is below range you would like him to do an iron panel and full blood count to see if you have iron deficiency anaemia as below range ferritin can mean you have this.

Also, what are your thyroid results that you have been told are normal? Please post results with reference ranges for members to comment. I doubt they're anywhere near optimal because ferritin below 70 means that thyroid hormone can't work.

Have you also had other vitamins and minerals tested?




When one is deficient there are probably also other low levels.

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Iron panel and complete blood count have been done thanks.

Iron 9.1 (6.0 - 26.0)

Transferrin saturation 15 (10 - 30)

RBC count 4.42 (3.80 - 5.80)

WBC count 6.15 (4.00 - 11.00)

Haemoglobin estimation 115 (115 - 150)

Haematocrit 0.41 (0.37 - 0.47)

Mean corpuscular volume 78.2 (80 - 98)

Mean corpuscular volume concentration 387 (310 - 350)

Mean corpuscular haemoglobin 28.2 (28 - 32)

Platelets 252 (150 - 400)


Saralou9 So you have a ferritin level of 17 and your other results suggest iron deficiency anaemia. Has your GP said anything at all about these? If not then make an appointment and ask to be treated appropriately.

With your ferritin level that low ideally you need an iron infusion so ask for one, but you may only be prescribed tablets which will take months to raise your level whereas an infusion will raise your level within 24-48 hours.

Take each iron tablet with 1000mg Vitamin C to aid absorption and help prevent constipaton. Always take iron 4 hours away from thyroid meds and two hours away from other medication and supplements as it will affect absorption.

You can help raise your level by eating liver regularly, maximum 200g per week due to it's high Vit A content, and including lots of iron rich foods in your diet apjcn.nhri.org.tw/server/in...

(Ferritin needs to be at least 70 for thyroid hormone to work, ideally half way through it's range, but don't expect your GP to know this)

As for the iron deficiency anaemia, see NICE Clinical Knowledge Summary for iron deficiency anaemia treatment (which will be very similar to your local area guidelines)


How should I treat iron deficiency anaemia?

•Address underlying causes as necessary (for example treat menorrhagia or stop nonsteroidal anti-inflammatory drugs, if possible).

Treat with oral ferrous sulphate 200 mg tablets two or three times a day.

◦If ferrous sulphate is not tolerated, consider oral ferrous fumarate tablets or ferrous gluconate tablets.

◦Do not wait for investigations to be carried out before prescribing iron supplements.

•If dietary deficiency of iron is thought to be a contributory cause of iron deficiency anaemia, advise the person to maintain an adequate balanced intake of iron-rich foods (for example dark green vegetables, iron-fortified bread, meat, apricots, prunes, and raisins) and consider referral to a dietitian.

• Monitor the person to ensure that there is an adequate response to iron treatment.


Thanks no I was hoping the GP would have contacted me about them but he didn't so I will go back and ask for appropriate treatment.


Vitamin D 43.1 (25 - 50 vitamin D deficiency. Supplementation is indicated) taking 800iu vitamin D since 2013

Folate 1.7 (2.5 - 19.5)

Vitamin B12 205 (180 - 900)



Folate 1.7 (2.5 - 19.5)

Vitamin B12 205 (180 - 900)

You need to ask your GP why he has ignored your folate deficiency (you are way below range). Also your B12 is very low, do you have signs of B12 deficiency b12deficiency.info/signs-an... You should post on the Pernicious Anaemia Society forum for further advice then discuss what they say with your GP healthunlocked.com/pasoc/posts You may need testing for Pernicious Anaemia and you may need B12 injections. Don't start taking folic acid (which your GP may prescribe for the folate deficiency) until any other investigations have been carried out.

I have read (but not researched so don't have links) that BCSH, UKNEQAS and NICE guidelines recommend:

"In the presence of discordance between test results and strong clinical features of deficiency, treatment should not be delayed to avoid neurological impairment."

And an extract from the book, "Could it be B12?" by Sally M. Pacholok:

"We believe that the 'normal' serum B12 threshold needs to be raised from 200 pg/ml to at least 450 pg/ml because deficiencies begin to appear in the cerebrospinal fluid below 550".

"For brain and nervous system health and prevention of disease in older adults, serum B12 levels should be maintained near or above 1000 pg/ml."

Folate should be at least half way through it's range.

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