Thyroid UK
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So what level Ferritin now?

Text taken from above link ......

*AS FAR AS THE 70-90 RANGE FOR FERRITIN: there were five

scholarly articles on the net referring to this 70-90 range from 2004 to 2012…but they have all disappeared i.e. the websites disappeared from the net. So most of what you will see on the internet are websites which saw this range HERE on Stop the Thyroid Madness (and fail to give STTM credit), and we at least had studies or articles to prove it. Now we don’t.

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What a minefield

I will watch this with interest!



What ranges (numbers in brackets) did your 47 ferritin test result have?



It is a shame that the site does not let us see the links that apparently no longer work. It wouldn't be the first time that links have stopped working but the linked-to item still exists. For example, the big scientific paper publishers seem forever to be reorganising how they handle things. Some papers now have to become open-access after a certain period (six months or a year) so they might pop-up on PubMed Central. Or even a server has failed but no-one fixed the problem!

Also, STTM excludes robots from searching so cannot be added to the WayBack machine.


Flower007, Ferritin and vitD lab values in USA and UK are different. USA ferritin top of range is around 150-200 whereas UK ferritin range is usually 300-400 which is why 'half way through range' is considered optimal.


300 - 400 - do you mean 30 - 400 Clutter??? It varies with age and gender, obviously.

Have been searching for studies on optimal ferritin on pubmed with no success so far,

is quite interesting in that it finds no strong links between ferritin levels and heart disease, though with women there may be a U shaped effect - ie, both very low and very high levels may have some association.

Association not being, as we all know, causation.


Aspmama, no I was talking about the top of the ferritin ranges being 300 to 400 in different areas of the UK.


Thanks Clutter. The USA's official NIH website on ferritin gives different top levels for men and women (!!) According to them -

Normal value range is:

Male: 12-300 ng/mL (nanograms per millilter)

Female: 12-150 ng/mL

They do point out that "normal" seems to mean "usual" which of course is far from "optimal".


Suggests that some haemos are thinking about this, but frustratingly the full text is not available.


Is this what you were looking for?


Interesting that they're arguing about this. That's an interesting letter, thank you humanbean but it's not the original research piece I think...


ThanksHumanbean! Called up the wrong one. Gosh! At last! In other words, the iron ranges themselves, even the ranges for anemia, may (and I am quite sure do) reflect an institutionalised discrimination against women in the medical world. I quote:

"It is considered “normal” to find lower red blood cell counts and lower haemoglobin and serum ferritin concentrations in menstruating women than in age matched men

No other mammal, including the menstruating primates, exhibits such a sex difference, and neither is there a difference in humans before puberty or after menopause

Menstruation is the main cause of iron loss in women; 90% of UK women do not achieve the daily recommended intake of iron from their diet

Populations used to establish reference ranges for women contained a large proportion of those with iron deficiency, thus the lower limits are too low

This hidden deficiency has fundamental implications for women's health, particularly adolescent girls

Male reference ranges for ferritin and haematological parameters may be of more value when assessing iron status in women."



Aspmama, ferritin/iron will be lower in menstruating women.


But because we menstruate doesn't mean the optimal level is lower for us. It probably means we should be eating more iron or taking supplements to keep the level up during those years. Levels will also vary for those who are fat, and they will vary also according to food intake.

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Aspmama, the inherent problem with populaton ranges is they are based on the mean average of 95% of the sample in an area, often only 200 samples, which don't screen out people with health problems who are unlikely to have 'optimal' levels and certainly doesn't take into account menstruation, weight and diet.



my ferritin was 47 range 20.00-250.00

Haemoglobin 124 120.00-160.00

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In the old days they seem to have "established" ranges by taking a group of people, say who worked in a hospital, testing them and then setting the range they found as normal. There's clearly a lot of potential problems in that!

So to get an ideal, or optimal range for serum ferritin, you'd have to take a large group of people who appeared healthy. You'd have to do a lot of blood tests to remove those with obvious diseases, like celiac, diabetes, anemia, D deficiency, any kind of inflammatory condition, etc, etc, and ideally I think you'd remove those with any reported gut symptoms. But they still might have underlying diseases like - hey! hypothyroidism, or heart problems. So it would have to be a prospective study on the remaining apparently healthy people over at least twenty years, at the end of which you might be begin to be able to see restrospectively what the ideal, healthy ferritin range is.

Do you think that study has been done yet?~!!!!

Is the nurses' study in the US establishing it? Is the prospective study in Bristol establishing it?


Contains one study suggesting it should be over 50.

The whole subject is complicated by the inflammation question.


Yes Aspmama,

I believe ferritin can be raised by inflammation, causing active iron to be pushed into storage, meaning it difficult to raise iron levels in people with Hashimotos.

Clutter, I don't understand what you mean by UK top of range being 300 - 400.

My ferritin range was 12.0 - 230.0

wally10 said hers was 20.0 - 250.0

And chickenmitch said hers was 15.0 - 200.0

I thought optimal was just half way through range.



Flower, the range in my area is up to 300 and range up to 400 is often posted . That's why it makes sense to advise half way through range rather than 70-90 which STTM recommends and which is based on US range.


Thank you. Now I understand what you mean.


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I've always had a problem with anyone (including STTM) declaring that the optimal range for ferritin is 70 - 90.

My first issue is that it makes no sense and cannot be relied upon without stating units of measurement. The units used for my ferritin tests and ranges has always been µg/L.

My second issue is that a result of 80 µg/L (for example) might be wonderful if the range is 13 - 150 µg/L, but it is a lot less wonderful if the range is 13 - 400 µg/L. (I've had tests from different sources and these are the two ranges used for my results.) In the first case the result is 49% of the way through the reference range, in the second case the result is only 17% of the way through the reference range - a huge difference! If people don't state the reference range they are comparing to when stating an optimal range then the numbers might just as well be random.

Regarding suggesting supplementation to people with low ferritin...

In an ideal world, ferritin would always be studied in conjunction with a full iron panel - Serum Iron, TIBC (Total Iron Binding Capacity), Transferrin Saturation % - and a full blood count - the levels most of interest are haemoglobin, red blood cell count, haematocrit, MCV and probably a few other things too.

The chart at the bottom of the following link is useful, but doesn't cover the situation where people have two or more different types of anaemia, which really muddles the issue :

In the real world of course, people often just have a ferritin level and no more. So, should we (on this forum) throw our hands up and say, sorry we can't help you? It will always be risky giving advice about iron on a forum (or even in a doctor's surgery) when the only information available is a ferritin level. People have to weigh up the possible benefits and the possible risks and make their own minds up what risks they are prepared to take. In the meantime, suggesting to people that they should get their ferritin up to mid-range and no higher seems like a reasonable compromise between doing nothing and trying to help, when there is insufficient information on which to make a decision.

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But - am I being very stupid here - if the units used to measure are the same, then the different ranges surely are the result of specialists taking a different view, in some cases a more informed view, of the available research. So in the States they are taking a much more cautious stance of the upper level of ferritin which is safe.

Which would not mean that a level half way through the range was good. It would just mean that the labs ranges here are often wrong.


The different ranges could be the result of using different machinery to do the tests.

I don't know (with certainty) how ranges are worked out, either here or in the US. All the suggested methods that I've ever read sound a bit slap-dash and dodgy to me.

As far as I'm aware, the optimal range for ferritin suggested on the STTM site is based on a reference range of 13 - 150 ug/L - in other words, it suggests that the optimal range is the same as mid-range, but doesn't actually say this explicitly. It gives hard and fast numbers i.e. 70 - 90. And that is dangerous, in my view, because it isn't mid-range for everyone.

Assuming that the distribution of results for ferritin in a healthy population follows a normal distribution, then the bulk of healthy people have a ferritin level in the middle of the range. Doctors always seem to assume that reference ranges are based on normal distributions, so one would hope that people on this forum are not likely to harm anyone by following the same method.

I know that assuming a normal distribution isn't true for everything. E.g. the distribution for TSH results is highly skewed and the median for the distribution is much lower than mid-range.

And another point - how can any of us say that the optimal range for ferritin is the same for healthy people and for hypothyroid people? Perhaps hypo people would do better with a lower or higher optimal range.

There are so many assumptions and grey areas that I doubt any of us can ever say with absolute certainty that "the ideal range for ferritin is X mcg/L - Y mcg/L, or is mid range, or is in the 30th - 40th percentile. So, do we refuse to help? Or do we make suggestions that should help people feel better while keeping the risk of doing damage to a minimum?

If the consensus is that we shouldn't make any suggestions like that, then I'll keep quiet in future.


"Assuming that the distribution of results for ferritin in a healthy population follows a normal distribution, then the bulk of healthy people have a ferritin level in the middle of the range."

That's two awfully big assumptions. With vitamin D, that led to the wrong levels being set.

Why would the different machinery, if it is testing the same units, and is working properly, come up with different figures? Surely it's much more likely that the levels are being set differently as cut off points based on different research? (Please please don't think I'm being aggressive or arguing for any reason except to try to work out what the truth is!! Really we need to trap a haemo or a lab technician under a spotlight and fire questions at him/er.)

There is some decent research suggesting over 50/60 is needed to prevent fatigue - that would be in women without any inflammatory condition. And there is a good amount of research/excellent clinical practice on the levels needed if there is Restless Legs Syndrome - up to 100. So between 60 and 100 is probably a relatively safe area, for adults, on the information that can be found. Which is close to the STTM suggestion.

I'll try to dig out a v g piece on iron deprivation I have somewhere.

"Do we make suggestions that should help people feel better while keeping the risk of doing damage to a minimum?" has to be right approach, hasn't it, for everything on the forum, emphasising that everyone has to monitor their own reactions closely. And ferritin is a symptom, rather than a cause, which is reassuring. And hepcidin puts its own brake on absorption, so that's reassuring too.


I agree 100% that assuming a normal distribution is a very big assumption to make, and it may be completely unjustified. But it is one that doctors seem to make all the time. So, from a practical point of view, if they can do it I'm assuming we can do it too, and in doing so we are unlikely to kill anyone if they follow the suggestions we make.

I think we are discussing two different things. You seem to be interested in identifying how to reconcile different reference ranges, whereas I am interested in whether we dare give people advice about iron at all. If we can't agree where the optimal reference range is, then perhaps we should keep quiet, and tell people to follow their doctor's advice. But not saying anything about iron to people with low in range ferritin would disturb me. If I had followed what my doctor said about iron I would probably be dead by now. It was only discovering that prescription-strength iron supplements were available without prescription, and that I could pay for comprehensive private blood testing without having to beg from a doctor that helped me to get better.

Why would the different machinery, if it is testing the same units, and is working properly, come up with different figures? Surely it's much more likely that the levels are being set differently as cut off points based on different research?

I don't know enough about laboratory testing to know how this situation could arise. I couldn't even begin to speculate. However, I would be wary of saying that the UK and the US ranges often differ, therefore the UK must be doing it wrong - because I wouldn't think there was available evidence for assuming that either.

( I'm not trying to be aggressive either. :D )


I agree, humanbean, I think the danger is the too low ferritin levels too. Maybe the agreement would be to say it looks as though going over 150 could be dodgy, whatever the ranges?

I am glad you are not getting cross with me. The reason I think the USA rates may be more accurate is a much bigger country, and has much better funded research programmes, and also I suspect (which is subjective thinking, I agree) that the NHS acts as a brake on thinking out of the box. UK doctors are rewarded for obeying the rules set by a central authority, and I think a certain degree of inertia sets in, and I would cite the fact that US endos changed the limit on TSH well in advance of the UK as evidence in support of my argument.

Private medicine in the US also acts as a bit of a brake, but I think there is more room for difference there, and doctors who can make an effective difference to their patients are more likely to be rewarded with more custom. Their rates of cure for cancer, I believe, are much higher.

So, I know you understand this, but others reading the discussion might not, let's imagine for the sake of argument that different countries have different values for weight. In the UK 15 stones might be considered acceptable as a top value for women, because many women in the population weight that. But it wouldn't necesssarily represent an ideal weight. There would be different kinds of weighing scales, but they're all measuring the same thing. Different countries would set different top levels. It would be a matter of judgement by the labs or the specialists. It would be potentially dangerous to take a level half way between the parameters.

So what we're discussing now is, is 150 ferritin - an absolute measurement, if not an absolute scale - a top, beyond which it may be risky to attempt to go?


The WHO says over 150 (for women) carries a high risk for iron overload, so I think it would be important to point that out... no range given, that was an absolute.


But as I pointed out in one of my other posts...

The two ranges for ferritin that I've had on my own personal testing are :

13 - 150 ug/L and

13 - 400 ug/L

Having a result of 150ug/L would suggest completely different things depending on the range used. In the first case the result would suggest iron overload is imminent, in the second case it would be quite a bit below mid-range.

This is why giving absolutes makes no sense to me. The reference range must be included for it to make any sense.


OK, we're going round in circles now Humanbean - much as I respect and admire you, we're going to have to differ on this.


I'm happy to just leave it. I'm not sure how we can reconcile the different ranges with the information that is currently available to us. I understand what you are saying but I can't see how to break the deadlock and come to a conclusion. So, adding more to the discussion probably won't achieve anything. Other people might find the discussion useful though. And I always prefer people to make their own minds up about what they do with their test results anyway. In the end, the risk is always borne by the individual who supplements or doesn't supplement, as they see fit. :)

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Hi again - I will have a go at resolving this one because it is really important if there is a chance of high serum ferritin being associated with heart problems, as some argue. It may take a while. I'd much rather research this kind of thing full time than clean my house and shop, but sadly the natives get restless when I stop.

But I think the problem will resolve over time in that NHS labs will adopt the WHO recommended ranges. My last test (a London hospital) had a top range of 150.


If the top of the range was always 150 then I would be happy to accept that the optimal range would be around 70 - 90 i.e. roughly mid-range.

It is the 70 - 90 figure being quoted as ideal when the range goes up to 300 or 400 that I am not happy with.

I've always assumed that the different ranges are caused by different equipment, different lab techniques etc, not that the underlying populations are vastly different.

An anecdote - for what its worth : I had a GI bleed. I saw lots of incompetent and sadistic doctors about it. It took three and a half years, three hospitals, and four consultants (one of whom I paid to see privately) for the source of the bleeding to be tracked down and fixed. By the time I was correctly treated I couldn't walk upstairs without either going on hands and knees very slowly, or going up on my bum, I was incredibly breathless and always gasping for air, I had constant burning chest pain, tachycardia, and I found it almost impossible to think and talk. I'd been taken into hospital with a suspected heart attack several times. I was always diagnosed with "atypical chest pain, you're fine, have a prescription for beta blockers, go away". It took me nearly two years to get my ferritin up to mid-range after I started taking prescription-strength iron and the bleeding was stopped, and my chest pain has been 98% cured in the process. I still get the occasional twinge. The heart needs iron. I agree that too much will be bad, but too little will be bad as well. I don't feel well if my iron and ferritin levels start dropping much below mid-range. It is the experience I have just described that makes me so "intense" on the subject of having enough iron.


I understand your position and I understand your passion - the damage to my son from having too little iron but no anemia may affect him for the rest of his life.

I will try to get to the bottom of it. Two things are clear, I think - 70 - 90 isn't an unsafe level so far as possible overdosing goes. Though it could be low, if you are right, on some ranges - most people posting here are way down of that. The other very clear and shocking thing is that the ranges themselves are arrived in a haphazard manner which lacks even a pretence of scientific rigour.

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I read somewhere quite recently (I wish I could remember where) that the reference range for B12 was originally set in 1947 using 7 patients with pernicious anaemia. It hasn't changed very much since.

Edit : A correction - it wasn't the reference range it was the recommended daily intake.



I thought mid-range was what people on this forum advocated anyway.

My post was based on where these ranges came from and the fact that STTM were recommending these when the evidence had disappeared from the net. But as Rod pointed out, the scientific papers would still be accredited, just not available on the original websites.

Thank you for the link which is really interesting as I have high ferritin and transferrin saturation levels indicating Heamochromotosis, still being investigated at present.



Although some people on the forum advocate mid-range for ferritin (which makes sense to me), I still see 70-90 quoted quite often (with no reference range or units), probably because people are still quoting the STTM numbers.

Since ranges vary from lab to lab, and country to country, specifying actual numbers is misleading, and for substances like iron which are potentially toxic I think it is dangerous. I have seen a range quoted by someone for ferritin on the forum quite recently for which the top of the range was in the 80s, although I don't remember the exact numbers. If anyone using that range had a level of 90 they might think everything was wonderful, based on the 70-90 figures quoted by STTM.


Can anyone explain the inflammation factor in easy to understand terms.

I had no aches or pains when my hair was falling out but a ferritin of 41.

I was given iron tabs ferrous sulphate and about 3 weeks into taking them I woke up one morning and every joint in my body was clicking, it was literally overnight. At my next blood test my ferritin had gone up to 47.

Is this linked or just coincidence?



Ferritin is the stored iron protein and can recycle iron for active use again.

When the body senses a potential threat, ferritin stores more iron to keep it safe and unavailable to the pathogen.

As inflammation can be caused by damaged cells, infections, irritants and even auto immune disease, Hashimotos can make ferritin levels raise and iron levels lower.

Usually a low level of ferritin would indicate a low level of iron but you can see this does not always follow when inflammation is involved.

I don't know why your body would ache so much on ferrous sulphate iron tablets.


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Hi Wally10, that's a small rise, I doubt the iron was to blame.

I'll try to explain my understanding on iron and inflammation.

Iron is essential to the body. However, iron is also used by bacteria and viruses in order to flourish. So if you have some kind of infection going on, the body will react by putting the brakes on the absorption of iron (it does this via hepcidin, which was only discovered in 1990) AND by putting more of the iron it does absorb into storage so that the bacteria and viruses are starved of fuel. The storage system is the serum ferritin.

The body probably pays a price for that in feeling tired, but the body thinks it's a price worth paying in the fight against the infection.

So if you have bacteria/viruses causing inflammation somewhere in your body, AND you have plenty of iron in your diet, your serum ferritin level will rise. It can go quite high, but it isn't telling youabout healthy iron levels - it's telling you about your inflammation.

So you have to deal with the source of inflammation before you supplement with iron.

Which is often not easy. But I stop my daughter's iron supps if she gets flu or a cold, for example.

The body gets rid of water soluble vitamins like the B group very easily - it washes them out in pee. But iron is different. The body doesn't have an easy way to get rid of it - it loses a bit in skin cells etc but it is a slow process. It needs a lot of anti-oxidants to help it deal with iron too. So too much iron is dodgy, just as too little iron is dodgy. But the emphasis in the past fifty years, it seems to me, has been on the dangers of too much iron, rather than too little - the same situation as with vitamin D.

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When I joined this forum two years ago, everyone kept saying ferritin level needed to be 70 -90. Mine was 88 in a range of 15 - 300 so I thought I'm fine.

It has since dropped to 68 which again I thought I am only a little under the 70.

When I saw an endo last year he said you need your ferritin to be over 100 to feel well,

I said what just us hypo's and he replied no everybody.

Now whether he mean't over 100 in the range our local lab. uses which is 15 - 300 or any range I do not know.


Browny, your endo will have meant you need ferritin over 100 within the range, not over it.


Yes now thinking about it he would have meant over 100 in my range, not sure what you mean by not over it Clutter.


I'm from uk. My serum ferritin is 16 ug/L (13 - 150) which they stated as *normal*

Iron studies - Serum iron level. 25.3 umol/L. (13.0 - 32.0). Serum transferrin 3.28 g/L (2.00 - 3.60)

TIBC 75 umol/L (45 - 70)

Saturation of iron 34% *Satisfactory* is stated on my results! All gobbledygook to me 😬


Hi Angela,

You are more likely to get responses to your questions about iron if you post in a separate thread of your own. It's going to be missed, being buried at the bottom of another thread.


Thank you humanbean...much appreciated! x


OK - see above for the madness of all this! On serum ferritin just above the bottom end of the scale is the point where you're not going to have anemia.

But that doesn't mean to say that on a serum ferrin of 16 you are well, or that is a healthy level. "Normal" doesn't mean "good".

It is a very low level of iron stores, and you might well be feeling very tired because of it, and it might be contributing to hair loss. One piece of research found that women did not stop complaining of fatigue until their levels got above 50 or 60. Personally in your situation I would take iron supplements to get at least above this level. If you read the thread you will find many links, and more discussions of this on other threads about iron.


See especially "Populations used to establish reference ranges for women contained a large proportion of those with iron deficiency, thus the lower limits are too low

This hidden deficiency has fundamental implications for women's health" from the paper written by qualified haemotologists referenced earlier.


Thank you aspmama...very interesting! I am so fatigue, plus allover body pain. I also have PBC, Fibro and been anaemic on and off for years - at one point I was told I was B12 deficient and may need injections for life, only to be told from another GP that I was now normal range and it must have been my diet! 😕


Thank you x


Angela, if you have antibodies to your thyroid you are at higher risk of having antibodies to the lining of your stomach. Around 35 per cent of those with Hashi's have autoimmune gastritis as well. If you have had anemia the likelihood of your being in that 35 per cent must be very high. The low ferritin is a clear sign of iron deprivation, and you have that on the authority of the World Health Organisation.

Have you been tested for anti parietal anitbodies, antibodies to intrinsic factor and serum gastrin? You may have Autoimmune Gastritis even if it has is not yet Pernicious Anemia - ie, you are not anaemic just now, but your low iron storage level and history suggests an absorption problem.

If not it would be useful to go back to whichever GP seems the most sane in the practice, with all the research references to support your request. If you search Polaris' posts in this forum you will find links and a summary to the latest guidance on testing for B12 deficiency. Basically, the current B12 test GPs use is pretty meaningless.


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