Very low TSH after starting on small dose of Levo

[Cookerybookaddict86]

Hi, could I ask for some advice? We've already had a lot of very helpful advice from this forum, so I hope it's okay to come back and ask for yet more advice! We're so appreciative of everyone who took the time to response to my previous posts.

I'm writing on behalf of my 18 year old daughter who is very unwell (chronic fatigue and many other hypothyroid type symptoms), and currently under the care of a private endocrinologist. Her FT4 and FT3 hormones came back as very low, but just in range, a couple of months ago - FT3= 3.4 (3.1-6.8) and FT4 = 12.7 (12 - 22), and normal TSH (1.75). She's also had a low 9am cortisol reading (242) but subsequently passed a SST, and last week we discovered that she may have iron deficient anemia (Ferritin = 15, and a RBC/Haemoglobin levels which have dropped very rapidly over the last month or so). Her vitamin D, B12 and Folate level are all very healthy.

Her endocrinologist started her off on 25mcg of Levo 5 weeks ago and this was increased to 37.5 mcg some two weeks ago (by alternating 25mcg and 50mcg each day). As I mentioned in a previous post this has done very little to alleviate my daughters symptoms although she does now have the odd day when her energy levels seem much better.

My daughter had her thyroid hormones tested again yesterday and the results are as follows:

FT3 = 3.6 (3.1 - 6.8)

FT4 = 16.4 (12-22)

TSH = 0.77 (this test was done at 8.15am and we followed all the patient to patient tips on this forum!)

While her FT4 has risen quite a bit since her last reading, her FT3 has barely moved at all; however, the main issue we now have is that her TSH has fallen and my daughter's endo says that she is concerned that if she increases her Levo any further, her TSH will end up suppressed which could be dangerous!

The endo has agreed to increase her Levo very slightly but only by adding an extra 25mcg per week (not per day!!) We asked her about T3 medication but she said that T3 wouldn't be advisable although she didn't really explain why this was.

Does anyone have any thoughts on all of the above as we're at a loss as to what to do next, and my daughter is completely distraught about the situation she's now in? She's got to the point where she feels as though she's never going to get better which is very hard at the age of 18.

I posted last week about her Ferritin levels and received lots of great advice, and as a result she's now booked in to an iron clinic, at a local hospital, for an iron infusion in a few weeks time. We're hoping that this might boost her energy levels a bit (and possibly her FT4 to FT3 conversion?), although we're still very concerned about how we raise her FT3 levels which are clearly much lower than they should be.

Many thanks.

[SeasideSusie Remembering]

It's very, very early days in your daughter's thyroid journey. It can take months to find the optimal dose. Each dose change requires up to 8 weeks for levels to stabilise. Her low ferritin wont be helping, some experts say that the optimal ferritin level for thyroid function is 90-110ug/L, so all in all lots of work to do, lots of patience needed. No quick fixes with this condition I'm afraid.

[Cookerybookaddict86 in reply to SeasideSusie]

Many thanks, Seaside Susie. My daughter's dose has been increased by just 3.5mcg a day, so it's certainly going to take many months at this rate. We're keeping our fingers crossed that the iron infusion may help at the end of this month.

[SlowDragon Administrator]

Did you decide to do coeliac blood test or was she not eating enough gluten to test

If not testing cut gluten out completely

Approx how much does she weight in kilo

She likely to eventually need something around at least 100mcg levothyroxine per day

So has a long way to go yet

FT3 = 3.6 (3.1 - 6.8)

FT4 = 16.4 (12-22)

TSH = 0.77

FT4: 16.4 pmol/l (Range 12 - 22)

FT4 only 44.00% through range so plenty of room for improvement

See what happens after iron transfusion

[Cookerybookaddict86 in reply to SlowDragon]

Many thanks, SlowDragon! We're hoping to see her Gastro next week to talk about testing her for coeliac disease.

She weighs 50kgs, so she probably is slightly underweight but she eats 3 good sized meals a day plus snacks. I'm pretty certain that her weight isn't the cause of her hypothyroid symptoms.

Yes, we think she'll probably start feeling better when she's on a much higher dose of Levo, the issue we have now though is that her TSH has dropped and her endo said she's very wary about increasing her Levo any further (from 37.5 mcgs) so we're a bit stuck!

[jimh111]

Her thyroid is getting insufficient stimulation from her pituitary. i.e. her TSH should be higher with her low normal fT3 and fT4 (both). As a consequence her fT3 will fail to pick up as TSH stimulates T4 to T3 conversion. She is likely to need liothyronine at some stage although it is very difficult to get it prescribed.

Some illnesses can cause a temporary fall in TSH leading to this sort of situation. So she may recover over the coming months. Hence it might be wise to go slowly for the moment to see if she spontaneously gets better. BUT if she doesn't show signs of getting better in a month or so I would push hard for some liothyronine.

[Cookerybookaddict86 in reply to jimh111]

Hi Jimh111, many thanks for your reply. Yes, we are going to push for liothyronine if things don't improve, although I have a feeling we may need to find another endo before we can do this.