Thyroid UK
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ferritin and folate levels

Hi all. Where should our ferritin and folate levels be within the ranges? My grandaughter's recent test show:-

ferritin 37 range 10.00 - 150.00 ug/L (down from 68.2 three months ago)

folate 5.3 range 3.00 - 20.00 ug/L (was 20.64 (10.4 -42.4nmol/L) three months ago)

Three months ago her B12 was 225. Sadly they didn't test it this time. She didn't take supplements for a week prior to the test in case it skewed the result - then they didn't even test it!

Thanks for all your help.

8 Replies

I suspect your grandaughter is already or is going hypothyroid

We see low levels of ferritin ,folate and b12 all the time on here

Without levels of




Vit d3

All being halfway in their ranges the body cannot utilise any levothyroxine


At least halfway up the range. B12 should be up the top of the range.

1 like

Thanks, Luley. These are her results three months ago, so no worries then.

Thyroid Function

TSH 1.43 0.28 - 4.3 IU/L

T4 Total 113.5 64.5 - 142.0 nmol/L

Free T4 16.21 13 - 23.2 pmol/L

Free T3 5.83 3.7 - 7.7 pmol/L

Immunology Anti-Thyroidperoxidase abs 8.4 <34 kIU/L

Anti-Thyroglobulin Abs 11.0 <115 kU/L

Vitamins Vitamin D (25 OH) 74

These were Blue Horizon. We had the tests done because I felt her symptoms were hypo - the the results are good. The doctor hasn't tested T3 (as you might guess), but her TSH now is 1.2 and T4 is 13.5 (10.4 - 24.5). Not too concerned by these - it's the B12 etc that needs the attention, I'm thinking.


Stopping B12 for a week would not be long enough to get a true reading. She would have to stop it for five months.


Crikey. I didn't realise. Thank you


Not many people do. :(



Ferritin should be half way through the range, so 80 with that range.

Folate should be at least half way through the range so 11.5+ with that range.

Is she supplementing either of these?

As your granddaughter has been taking a B12 supplement then further testing is useless. You need to be off B12 supplements for about 5 months if re-testing.

As she is taking B12, is she also taking a B Complex to balance the B vits? If she takes Thorne Basic B or Jarrows B Right then they both contain 400mcg methylfolate which will help raise that low folate level.


No, she's not supplementing these yet, but she soon will be. I thought they were low, but was surprised that they were going down. Thank you for taking the time to reply.


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