Am I a poor T4 to T3 converter?: I had thyroid... - Thyroid UK

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Am I a poor T4 to T3 converter?

Meadowsmom profile image
11 Replies

I had thyroid hemithyroidectomyvin October of 2017, but become hypothyroid about a year later and started on medication. From October 2018- December 2018, I used Thyrogold, 50-75 mg, but dosing was difficulty and gained too much weight on the supplement. I January I switched over to 50mcg Synthroid. I have lost 3-4 pounds but I have sustained hair thinning with Synthroid and some tiredness in evening but otherwise feel ok on Synthroid. My latest blood labs in late February 2018, after 7 weeks of Synthroid usage:

TSH. 1.870 (0.459-4.500)

Free T4. 1.24 (0.82-1.77)

Free T3. 2.5 (2.0-4.4) (12/28/18 on Thyrogold previously was 3.1–big drop)

RT3. 20.1 (9.2-24.1)

Thyroglobulin AB <1.0 (0.0-0.9)

Additional blood labs January 9, 2019, as follows:

Vitamin D 46.0 (30-100.0)

B12. 1245 (232-1245)

Ferritin 76 (15-150)

Folate >20.0 (>3.0)

Iron 98 (27-159)

I missed taking my Synthroid for 2 days prior to getting my latest labs because I misplaced the medication😒 and not sure if this had an impact on results of my latest blood labs. Do I need more time on Synthroid to determine whether I am a poor converter?

Your comments are appreciated. Thanks.

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11 Replies
greygoose profile image
greygoose

Yes, you really do need more time. Those labs are useless if you didn't take your Synthroid for three days. Your FT4 would be quite a bit higher than that, and three days is probably long enough to affect your TSH, too. But, we don't really know because we have nothing to compare it with. Impossible to tell anything for certain with those labs. You need to be on a steady dose for six weeks before retesting. And just leave off your Synthroid for 24 hours before the blood draw.

Your vit D and ferritin/iron are a little low. Are you supplementing these? :)

Meadowsmom profile image
Meadowsmom in reply togreygoose

I made some mistakes it the original posts, sorry. I missed 2 not 3 days of medication prior to testing. I found the medication and took it 24 hours prior to testing and again the next day after testing had concluded. I otherwise took Synthroid correctly for a little over 6 weeks prior to getting the blood draws.

The ferritin range has also been edited to the correct range of 15-150.

The rest of my iron blood labs were:

Iron binding capacity TIBC. 325(250-450)

UIBC. 227 (131-425)

Iron saturation 30% (15-55%)

The doctor said that my iron levels were fine so I do not supplement iron

But I am now supplementing with vitamin D to get that range higher. Thank you for your response.

greygoose profile image
greygoose in reply toMeadowsmom

There's no way of knowing just how much of an effect missing two days would have on your results. That sort of thing just hasn't been researched. So, if I were you, I would taking it that that FT4 is not reliable, although it probably wouldn't have affected the TSH and FT3.

And your ferritin is just ok, no more. Try eating liver once a week to bring it up a bit. It would be better up around 100. And the liver would bring it up naturally. :)

Meadowsmom profile image
Meadowsmom in reply togreygoose

Thank you Greygoose. I just started eating liver and will continue to do so once per week. I really like it and as as always,I appreciate you and your help!

greygoose profile image
greygoose in reply toMeadowsmom

You're welcome. :) Bon appétit!

SeasideSusie profile image
SeasideSusieRemembering

Vitamin D 46.0 (30-100.0)

As you are in the US, presumably the unit of measurement is ng/ml? In this case the level recommended by the Vit D Council is 50ng/ml and the Vit D Society recommends 40-60ng/ml, so your level is just about OK if it is ng/ml.

B12. 1245 (232-1245)

Ths is quite high, do you supplement?

Folate >20.0 (>3.0)

This should be OK, a high folate is apparently OK if B12 is high. Again, do you supplement?

Ferritin 76 (15-50)

That's not a range we see in the UK. We tend to see 13-150 or 15-300 here, and it's said that ferritin is recommended to be half way through it's range, with a minimum of 70 for thyroid hormone to work.

Iron 98 (27-159)

Serum iron is optimal at 55-70% through range - higher end for men. Yours is 54% through range so is just about right for a female.

Meadowsmom profile image
Meadowsmom in reply toSeasideSusie

I am in the US and the measurement is ng/ ml. I made a mistake in the original post and the correct reference range for ferritin is 15-150. I do not supplement B12 or folate as both of those have naturally been on the high side as evidenced by my blood draws over the last year or so. My complete iron profile from the labs also I included:

Iron binding capacity TIBC. 325(250-450)

UIBC. 227 (131-425)

Iron saturation 30% (15-55%)

I am concerned that my high reverse T3 is now higher and at top of the range. Also concerned that my T3has dropped quite a bit since discontinuing Thyrogold (was 3.1 when on Thyrogold) and is now at the bottom of the range which is probably contributing to my hair issues along with the Synthroid. Is Cytomel usage warranted to get T3 higher?

I am now supplementing with vitamin D3. Thanks.

SeasideSusie profile image
SeasideSusieRemembering in reply toMeadowsmom

I am now supplementing with vitamin D3

How much D3? You have to be extremely careful not to reach toxicity level as you are already within the range recommended by the Vit D Society. I certainly wouldn't go higher than 60ng/ml so retesting twice a year when supplementing is essential. Are you also taking D3's important cofactors, particularly magnesium and Vit K2-MK7

vitamindcouncil.org/about-v...

Iron binding capacity TIBC. 325(250-450)

- this is fine. High in range indicates need to supplement, low in range indicates you don't need to supplement. You are just below half way through range.

UIBC. 227 (131-425)

- this tends to be used in calculating TIBC and you have a satisfactory TIBC result.

Iron saturation 30% (15-55%)

- optimal is 35%-45% (higher end for men), with a minimum of 30% needed to successfully treat with T3.

Ferritin 76 (15-150) - this is almost half way through range, and over the 70 required for thyroid hormone to work.

The doctor said that my iron levels were fine so I do not supplement iron

I would agree with that.

I missed 2 not 3 days of medication prior to testing. I found the medication and took it 24 hours prior to testing

That's very confusing, either you left 2 days or you left 24 hours between last dose of Levo and blood draw.

Your FT3 will have dropped because you've stopped the Thyrogold which, I have heard, has a ratio of T4:T3 of 4:1, so very similar to NDT. But because we don't know the exact timing of how long you left between your last dose of Levo and blood draw, we still can't accurately comment on your thyroid results.

RT3. 20.1 (9.2-24.1)

I am concerned that my high reverse T3 is now higher and at top of the range

I wouldn't be concerned about that. It's within range at 73%, I wouldn't call that top of range. Even if it was over range, the test can't tell us what has caused it to be over range and there are very many reasons for over range rT3, not just thyroid related.

Meadowsmom profile image
Meadowsmom in reply toSeasideSusie

Let me try to clear up the confusion, so sorry. I took the medication on Sunday-Tuesday, missed it Wednesday and Thursday, took it Friday morning at 5am (usual time), and had blood drawn the next day (Saturday morning) at 8 am and resumed taking medication after blood was drawn that day. I otherwise took medicine correctly for a little over 6 weeks before getting blood labs taken. Hope this makes sense.

I am not taking vitamin K2-Mk7 but I do take magnesium daily. The vitamin D3 that I take is low dose, 200 IUs x 2 day.

SeasideSusie profile image
SeasideSusieRemembering in reply toMeadowsmom

Out of the 6 days prior to blood draw, you missed 2 days of Levo. In that 6 days you would normally have taken 300mcg Levo, and you took 200mcg. I don't know if that will make a difference to your thyroid hormone levels, I wouldn't be testing mine unless I'd taken my Levo as normal for 6 weeks.

By the way, T4 and T3 - are those Total T4/T3 or Free T4/T3? As US ranges for the hormone tests are different from the UK ranges, we don't know. If Total then they're not much use, it's the Free T4/T3 that tell us what's going on.

Meadowsmom profile image
Meadowsmom in reply toSeasideSusie

Free T3 and Free T4. BTW, I am not taking vitamin K2-Mk7 but I do take magnesium daily. The vitamin D3 that I take is low dose, 200 IUs x 2 day. I usually medication as normally should and this mishap was an anomaly. My husband was critically ill and I was so stressed that I misplaced the medication. I will take labs again in 6 weeks. Thank you so much for your help, much appreciated Seaside,

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