Hi there I wonder if anyone is knowledgeable in Adolescent Thyroid Lab ranges and optimal levels
My 17yr old daughter has the following results. I’m led to believe that the lab ranges are different by age and sex for adolescents. Is that so? What are they if so
Ive seen an article from a Canadian Thyroid site that indicates this also
Here are her results
TSH -1.5 (0.68-3.35)
FT3-5.4(3.5-5.3)
FT4 - 9(7.9-13.6)
thank you
This may be useful ... thyroidpatients.ca/2022/07/... pediatric-teenage-tsh-ft4-ft3/
thyroidpatients.ca/2022/08/... advanced-lessons-age-sex-tsh-ft4-ft3/
thyroidpatients.ca/2020/10/... normal-ft3-ft4-thyroid-hormone-ratios/
yes it’s this article!! Based on this and if I’m reading it correctly she is low on both T4 and T3 …
i stumbled across this the other day :
tandfonline.com/doi/full/10...
"At birth, a newborn quickly adapts to extrauterine life by developing a state of relative overactivity of the thyroid gland .
A sudden burst of thyrotropin-releasing hormone and TSH release, reaching up to 70–100 mIU/L within 30 min of birth, leads to a two- to six-fold increase in circulating T4 and T3 concentrations.
TSH significantly decreases to within normal infant concentrations in the first 3–5 days of life, while FT3 and FT4 serum levels remain elevated for several days and act on tissues.
Thus, the interpretation of RIs of TSH and FT4 for newborns must take into account the gestational age and postnatal age up to one month old.
Thyroid hormone concentrations then decrease slightly during childhood and adolescence.
There is also a progressive decrease in thyroid T4 production, iodine turnover, and absorption with age, which produces an overall progressive decrease in thyroid function. The concomitant drop in TSH during this period suggests that it is the primary mediator of these effects.
Serum TBG concentrations increase up to age 5 years; this increase contributes to the gradual dissociation between FT4 and T4 .
Subsequently, the TBG concentration, which decreases between 15 and 16 years of age, results in a gradual decrease in serum concentrations of total T3 and T4."
OK am going to have to keep an eye on this and check again. She does have some low-ish other bloods (Vit D and Ferritin) which GP has said is fine, but is actually lower end of ranges. Thank you 🙏
Katikoo
I’m led to believe that the lab ranges are different by age and sex for adolescents. Is that so? What are they if so
When your daughter's blood sample was sent to the lab, all relevant details would have been included and that includes her age, so whatever the appropriate reference range is for her age will be given with her results. Whether or not they differ from the adult range for that lab we I don't know.
So the results you've posted above show low in range FT4 and slightly over range FT3.
Does your daughter have a diagnosed thyroid condition and is she on any medication?
Thanks for replying. No she doesn’t. I myself do have UAT, and these are the same ref ranges that I have???? . She does not display any hyper symptoms. If anything more hypO.
Katikoo
I myself do have UAT, and these are the same ref ranges that I have????
OK, so it looks as though the range for a 17 year old is the same range used for an adult with your lab.
You can always look to see if your hospital's lab has the ranges online. I expect the ranges vary from lab to lab, some will class a 17 year old as a child, some will have a range for, say, 16-18, and some will class a 17 year old as an adult.
I have found the following by using Google, they do not apply to yours unless you come under these areas but it shows how they can differ, Sheffield has a range for 9-19 years but North Bristol's ranges are the same for all over 3 years from what I can see:
Sheffield Children's NHS Foundation Trust
FT4
7 days - <2 months 14.0-27.5
2 month - < 9 years 11.6–21.6
9 years - <19 years 9.8–18.9
FT3
0 – 1 year 3.4–7.6
1 – 5 years 4.3–7.2
6 – 10 years 4.4–6.8
11 – 14 years 3.4–6.5
15 – 18 years 2.9–6.8
and from North Bristol
Free T4 pmol/L
Gender - Age - Low - High
Both - 0–14 days - 17-57
Both - 15 days- 3 years - 9.5-17.8
Both - >3 years - 7.9-14.4
Free T3 pmol/L
Gender - Age - Low - High
Both - 0–14 days - 4.3-6.9
Both - 15 days - <3 years - 4.0-6.2
Both - >3 years - 3.8-6.0
Was your daughter's test done at 9am, nothing to eat or drink exept water beforehand, no biotin/B Complex or any supplement containing biotin?
yes
A normal healthy person with no known thyroid condition would have TSH of no more than 2, often around 1, with FT4 mid-range-ish.
So with those ranges, and I'm assuming that they're correct for her age with your lab, show that her TSH is about right but her FT4 is low in range.
What symptoms are present that are suggesting that she is Hypo?
Has she had key nutrients tested - Vit D, B12, Folate and Ferritin? Low levels can give symptoms that overlap with symptoms of hypothyroidism.
So yes I’ve had the following tested and GP saying fine, but I can see there could be the problem. Please see below. I think she is def low Vit D and Ferritin (reason for bloods were her heavy periods) - she does get tired easily and likes to nap( but she is a TEENAGER!! after all) but also really cold hands and feet, and I want to say brain fog, sometimes I feel she is studying really hard but not quite getting it right (it’s so hard to establish at this age)
Serum Iron 24.8(4-31)
Serum Transferrin 2.69(2-3.6)
Serum TIBC 61(45-75)
Transferrin Sat % 38
Serum Ferritin 31(11-306.8)
Vit D 54.5(5-150)
Serum B12 147(133-675)
Folate 6.3 (3.1-19.9)
I’ve got Omegas, Vit D3/k2, good B complex and some black strap molasses plus probiotics for now. VitD3/K2 3000🙏
Katikoo
Serum Iron 24.8(4-31)
Serum Transferrin 2.69(2-3.6)
Serum TIBC 61(45-75)
Transferrin Sat % 38
Serum Ferritin 31(11-306.8)
OK, so optimal iron panel levels according to rt3-adrenals.org/Iron_test_... are:
Serum iron: 55 to 70% of the range, higher end for males - hers is 77% through range so a little high
Saturation: optimal is 35 to 45%, higher end for males - hers is 38% so just about right
Total Iron Binding Capacity (TIBC): Low in range indicates lack of capacity for additional iron, High in range indicates body's need for supplemental iron - hers is 53.33% so mid range
Ferritin: hers is 6.76% through range. Ranges vary a lot for ferritin and some experts say the optimal level for thyroid function is 90-110ug/L
We can see that her ferritin is low but the rest of her iron panel is fine so she doesn't have iron deficiency just low ferritin. Symptoms of low ferritin include:
◾Weakness
◾Fatigue
◾Difficulty concentrating
◾Poor work productivity
◾Cold hands and feet
◾Poor short-term memory
◾Difficulty remembering names
◾Dizziness
◾Pounding in the ears
◾Shortness of breath
◾Brittle nails
◾Headaches
◾Restless legs
Supplementing with iron tablets wouldn't be advisable because that would raise her serum iron and saturation more and could lead to iron overload. The best way to start trying to raise ferritin is through diet (and being a teenager I don't suppose she'll like the recommendations). She can help raise herr level by eating liver regularly, maximum 200g per week due to it's high Vit A content, also liver pate, black pudding, and including lots of iron rich foods in her diet
bda.uk.com/resource/iron-ri...
everydayhealth.com/pictures...
I’ve got Omegas, Vit D3/k2, good B complex and some black strap molasses plus probiotics for now. VitD3/K2 3000
Has she started taking any of the supplements you've bought?
Vit D 54.5nmol/L(5-150) = 21.8ng/ml
You might want to check out a recent post that I wrote about Vit D and supplementing:
healthunlocked.com/thyroidu...
and you can check out the link to how to work out the dose you need to increase your current level to the recommended level.
Her current level of 54.5nmol/L = 21.8ng/ml
On the Vit D Council's website
web.archive.org/web/2019070...
you would scroll down to the 3rd table
My level is between20-30 ng/ml
The Vit D Council, the Vit D Society and Grassroots Health all recommend a level of 100-150nmol/L (40-60ng/ml), with a recent blog post on Grassroots Health mentioning a study which recommends over 125nmol/L (50ng/ml).
So now you look at how much is needed to reach 50ng/ml and you'll see that they suggest 3,700iu per day, nearest is 4,000.
Is the D3/K2 one of the oral sprays? One that 3 x sprays = 3,000iu? If so then just increase to 4 sprays a day. If it's a supplement that's swallowed then she'll need to take 28,000iu per week so you can work out the nearest to that and take whatever extra is needed to achieve that amount over the week.
Don't forget that magnesium is an important cofactor of D3, it helps the body convert D3 into it's usable form. Check out the different forms of magnesium and choose the one most suitable to her needs:
naturalnews.com/046401_magn...
The following link is included purely to describe the different forms of magnesium, ignore the fact that it mentions calcium is necessary, calcium is only necessary if you test and found to be deficient and then your GP should address that
explore.globalhealing.com/t...
and ignore the fact that this is a supplement company, the information is relevant:
swansonvitamins.com/blog/ar...
Serum B12 147(133-675)
This level is very concerning and I urge you to get her doctor to test for B12 deficiency and Pernicious Anaemia.
Does she have any signs of B12 deficiency – check here:
b12deficiency.info/signs-an...
b12d.org/submit/document?id=46
If she does then list them to discuss with your GP and ask for testing for B12 deficiency and Pernicious Anaemia. Do not take any B12 supplements or folic acid/folate/B Complex supplements before further testing of B12 as this will mask signs of B12 deficiency and skew results and if you have B12 deficiency and it is not detected and treated then this could affect your nervous system. B12 deficiency should be treated before starting folic acid because folic acid can sometimes improve your symptoms so much that is masks B12 deficiency.
If doctor says it's within range so no need for testing then argue about how low it is through range and push for testing. Don't give up, if she has symptoms then these must be given priority over any numbers where B12 is concerned.
Folate 6.3 (3.1-19.9)
This is low but not folate deficiency. We suggest at least half way through range so with that range you're looking for 11.5 plus.
Hopefully the B Complex is a bioavailable one with methylfolate and methylcobalamin and not folic acid and cyanocobalamin. B12 injections/supplements must be started before a B Complex or folate/folic acid supplement.
Don't start all supplements at once. Start with one, give it a week or two and if no adverse reaction then add the next one. Again, wait a week or two and if no adverse reaction add the next one. Continue like this. If you do have any adverse reaction then you will know what caused it.
It's very likely that her poor nutrient levels are causing her symptoms, work on these for a few months then retest all plus a full thyroid test to include antibodies. If GP wont do all then Blue Horizon will test under 18s and their Thyroid Premium Gold is an ideal test to include all that is needed.
thank you so much for such a comprehensive reply
She hasn’t started any supplements yet
Vit D is tablet form. -I’ll check the link 🙏
Strangely she likes chicken livers so may have to up that and include in everything
The list of symptoms of fatigue and lack of focus and concentration re ferritin were surprising as it confirms what I have been “feeling”. I am going in to discuss her B12 levels further with GP I agree this looks too low and as the link suggests Ferritin and B12 are linked
BComplex I have is Life Extensions BioActive B Complex - it’s because GP said levels were fine I got these to supplement her myself but it sounds like it needs higher doses??
I will begin with 1 supplement at a time 🙏
Once again thank you for your help x
With such extremely low B12 she needs testing for Pernicious Anaemia BEFORE starting any B complex or separate B12
BComplex I have is Life Extensions BioActive B Complex - it’s because GP said levels were fine I got these to supplement her myself but it sounds like it needs higher doses??
It seems there are quite high doses in that supplement already:
Amount per serving (2 capsules):
Thiamine (vitamin B1) - 100 mg
Riboflavin (vitamin B2) - 75 mg
Niacin (vitamin B3) - 100 mg
Vitamin B6 - 20 mg
Folate (vitamin B9) - 400 mcg
Vitamin B12 (as methylcobalamin) - 300 mcg
Biotin (vitamin B8) - 1000 mcg
Pantothenic acid (vitamin B5) - 500 mg
Is that correct, as I've seen some suppliers show an image where the B6 is 100mg and that is way too high, 10mg is supposed to be the safe amount for regular use.
Compare that to Thorne Basic B which is most often suggested here:
Vitamin B1 (Thiamin HCI) - 110mg
Vitamin B2 (Riboflavin 5'-Phosphate Sodium) - 10mg
Vitamin B3 (Niacin) - 10mg
Vitamin B3 (Niacinamide) - 130mg
Vitamin B6 (Pyridoxal 5'-Phosphate) - 10mg
Folate (L-5-MTHF) - 667mcg DFE (gives 400mcg methylfolate)
Vitamin B12 (Methylcobalamin) - 400mcg
Biotin - 400mcg
Vitamin B5 (Pantothenic Acid) - 110mg
Obviously don't start B Complex until after B12 in some form started but she needs to be tested for B12 deficiency/PA first.
Chicken livers = excellent, said to have more iron content than other forms 
Yes it says B6 100mg!
I won’t give them to her I’ll take them myself!
I’m going to see if I can get into yhe GP this week and take forward the B12/pernicious anaemia diagnosis
Hi SeasideSusie
Im after further advice please.
I have since been to see the GP and they have run repeat (not additional) tests.
Please see below her results.
Sadly they are still saying her level is still within the normal range. I specifically emailed linking NICE guidelines and BMJ both of which state under 200 should be taken as B12 deficiency and between 200-300 requires additional testing.
The Locum has said that local guidelines doesn’t follow NICE, only lab ranges
Her levels all look bad to me. ( still no supplements) Her folate has actually dropped from 6.7 to4.9 and apart from Ferritin increasing to 51 from 31 all her other Fe results have gone down . Her Vit D has increased slightly, because I’m getting her to go outside more
B12/folate level
157 pmol/L(133 - 675)
Serum folate 4.9 ug/L(3.10 - 19.9)
Iron Studies
Serum iron level
15.1 umol/L(4 - 31)
Serum transferrin
2.54 g/L(2.0 - 3.6)
Serum TIBC
58 umol/L(45 - 75)
Transferrin saturation index 24 %
Serum ferritin
51 ug/L(11.0 - 306.8)
Combined total vit D2 + D3 1v1
72.5 nmol/L(50 - 150)
I don’t know how to progress this further? Should I get her a private referral? Would they say the same thing?
She has Alevels next year and Im worried she’s not performing at her best 😔🙏🙏
Katikoo
For further advice on B12 and how to go forward I would suggest that you post all relevant information, test resuts and ranges on the Pernicious Anaemia forum as they will be able to help specifically with B12 and folate:
apart from Ferritin increasing to 51 from 31 all her other Fe results have gone down
I gave information about optimal iron panel results in my reply above.
Serum iron level 15.1 umol/L(4 - 31) = 41% through range, was 77%
Serum transferrin 2.54 g/L(2.0 - 3.6) = 33.75%, was 43.13%
Serum TIBC 58 umol/L(45 - 75) = 43.33%, was 53.33%
Transferrin saturation index 24 %, was 38%
Serum ferritin 51 ug/L(11.0 - 306.8) = 13.52%, was 6.76%
Iron is complicated and I have no idea if her heavy periods have anything to do with this, it may have depending on whether the test was done at the same stage through her cycle as previous test.
Vit D: 72.5 nmol/L
This is improving. You have information from my previous post on how to supplement. Is she using the dose of D3 suggested above, ie 4,000iu daily? If so continue until she reaches the recommended level, keep testing every 3 months until she does then once she has reached that level she'll need to find her maintenance dose to keep it there.
Presumably D3 and magnesium being taken?
thank you so much for your assistance-I’ve taken on board your advice re supplementing and will go ahead with those. I wasn’t aware of the PA group so will hope onto there. Thanks again x
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