Medichecks ferritin range 30-650 ug/L

[Judithdalston]

I have been having trouble for years with low ferritin, despite eating black pudding 3 times a week and taking ferrous fumarate. This last week got full thyroid blood tests back and thought ‘oh good , ferritin had gone up a bit to a decent 77’, but no, the range had been changed to a huge 30-650 ug/L. So mine is only 6% through the range, in August ‘21 and for couple of years previously had been c. 28% ( low 50s in range of 13-150) . Private Endo. thought that was fine, but my hair is falling out a lot at the moment. What % should it be for best outcomes?

[Jaydee1507 Administrator]

Have they just changed the range to include males as that would increase it a lot? On the orifinal range of up to 150, 75-100 is what to aim for which likely still stands on this range tbh.

[SeasideSusie Remembering]

Judithdalston

It would seem that Medichecks has started to use a new lab to process their tests - INUVI - and this lab has this very wide range for ferritin. When they use Eurofins County Pathology (which they have previously for many years, and occasionally The Doctor's Laboratory) the range is 13-150. In both cases the unit of measurement is ug/L. I would be inclined to contact them and ask them how can there be such a difference in the range when the unit of measurement is the same.

[Judithdalston in reply to SeasideSusie]

thanks, I have emailed them for an explanation

[SeasideSusie Remembering in reply to Judithdalston]

Can you let us know what they say please JD, I'm totally confused by this new range.

[Judithdalston in reply to SeasideSusie]

This is most of their reply, as you had anticipated:

‘The lab used for your most recent test uses a different analyser, which would in turn provide different reference ranges. Laboratories may use different analysers which will have different testing methods and different reference ranges. Medichecks, in the main, uses 3 different laboratories this means that there can be some variation in reference range depending on which laboratory your sample goes to. This is why we would advise to always look at where your result lies within a reference range rather than try to compare absolute results. ‘

The last sentence is rather confusing, the 77 ug/L result was very good for me, and risen from 51-2 ug/L the year or two before with a considerable effort, yet by doing as Medichecks suggest and not comparing such absolute results, I look at the reference range I have now dropped from about 28% through a range to a paltry 6%! I have emailed them back for more info., to explain this phenomenon, and how they now have a range up to 650 with same ug/L.

I remember noting it had post to Nottingham for a change.

[SeasideSusie Remembering in reply to Judithdalston]

Yes, when you work out the percentage through range it shows what nonsense they've said about looking at where your result lies within a reference range rather than try to compare absolute results.

Was it Eurofins they used previously? You can check which lab they've used by looking at the pdf of your results which you can download, it will show the lab top right of the page. I know the 30-650 range is INUVI and even if it was a male range that's higher than usual, male range is often up to 400.

[Judithdalston in reply to SeasideSusie]

Inuvi Diagnostics is what is on the blood results!

[SeasideSusie Remembering in reply to Judithdalston]

Was it Inuvi when the results were 77 and 51.2?

[Judithdalston in reply to SeasideSusie]

No, Eurofins and Drs Lab when results in 50s ug/L

[Judithdalston in reply to SeasideSusie]

See reply below to slow dragon with at least a modification to range!

[humanbean]

30 - 650 is an absolutely absurd range. Anyone with a result of 650 has a result which is nearly 22 times higher than the bottom of the range.

[Judithdalston in reply to humanbean]

See reply below to slow dragon with at least some modification in range!

[Judithdalston]

Quite! It is Inuvi Diagnostics as Seasidesuzie thought it might be. I had been wondering whether it had been a human error tapping the wrong data in, but seems not.

[ValDee88]

Thanks for following this up. Im in the same position and was also befuddled by the enormous range🤷‍♀️

[SlowDragon Administrator]

Did you get any further response from Medichecks?

[Judithdalston in reply to SlowDragon]

last email said they would ask a doctor, and would hear back then! I am going to ask if a customer can specify not Inuvi in future as a ferritin result appears nearly useless from them.

[Judithdalston in reply to SlowDragon]

Got the Medichecks reply :’Our physician has come back to me with a further response to your email. They have advised as follows: We have received further information the lab about ferritin reference ranges. They confirm that they are sex dependent up to the age of 60, then beyond the age of 60 the reference range is the same for both sexes: 

Males 16-60: 30-400 ug/L

Female's: 16-60: 30-150

Both >60: 30-650 

The lower limit of 30 ug/L is in accordance with the updated NICE guidance and the upper limits are in accordance with guidance from the Association of Clinical Biochemists. ‘

So over 60s seem to be able to go up to 650 quite happily! I wonder what that would do to the rest of my organs?

[SeasideSusie Remembering in reply to Judithdalston]

So for under 60s the ranges are more or less the same as Eurofins County Pathology and The Doctor's Laboratory.

I wonder what happens when you reach 60 🤔

So for a female at age 59 years and 364 days a ferritin level of 90 isn't too bad at 50% through range (30-150) but at age 60 years and 1 day it suddenly drops to 10% through the age appropriate range of 30-650 🙄

And whatever happens when you reach 60 hasn't anyone told Eurofins and TDL.

As the lab has our date of birth I wonder if INUVI are actually checking this and using the appropriate range when reporting.

I'm still not convinced.

[SlowDragon Administrator in reply to Judithdalston]

That’s really helpful

Brilliant that minimum/bottom of range increased to 30

If ferritin is over 300……Get full iron panel test ever 2-3 years to check iron isn’t high too

[SlowDragon Administrator in reply to Judithdalston]

will tag SeasideSusie and humanbean re this info

[helvella Administrator in reply to Judithdalston]

The Ferritin monograph from the Association of Clinical Biochemists says:

4. Reference intervals and variance

The normal reference interval has a wide range because of age and gender variations. Intra-individual variation of serum [ferritin] is very low and no circadian variation has been determined. The reference interval also has considerable variation depending on method used and therefore should be individually determined for each laboratory.

4.1.1 Typical reference interval (adults)

Men, 20–60 years: 30–400 μg/L

Women, 17–60 years: 15-150 μg/L

Men and women, 60–90 years: 15–650 μg/L

4.1.2 Reference intervals (others)

Children, 6 months to 15 years: 7–140 μg/L

5.1.3 Extent of variation

5.1.3.1 Interindividual CV: 15%

5.1.3.2 Intraindividual CV: 14.2%

5.1.3.3 Index of individuality: 0.95

5.1.3.4 CV of method: 4% for [ferritin] 100–300 μg/L

10% for [ferritin] 10–20 μg/L

5.1.3.5 Critical difference:

5.1.4 Sources of variation

Serum [ferritin] in adults ranges from 15–300 μg/L between 20– 50 years. From puberty to middle age (<50 years), men have higher [ferritin] than women of the same age. During the post-menopausal period, the gender difference disappears. Children have typically have lower [ferritin] than adults.

acb.org.uk/asset/AFFD023A%2...

Worth looking at the full document as it makes many other points.

I'm still not happy with the reference interval being so different.