Thyroid UK
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Cortisol Test Result

Hi, I had my results back today from Endo, but none of them have come back with any reference ranges..typical..

Anyway, my Cortisol which was taken at around 11.00a.m. has come back at 201, that's it, I have been told I will need a short synacthen test..

My TSH is 11, Free T4 13 and Vitamin D 16

I currently take 150mcg Levothyroxine

All comments welcome..

11 Replies

With a TSH of 11 you are not on a sufficient dose of thyroid hormones. You need an increase so if your Endo looked at your results he should inform your GP or see your GP yourself.

If your cortisol is high, taking Vitamin C will reduce it. This is an excerpt:

Earlier studies showed that vitamin C abolished secretion of cortisol in animals that had been subjected to repeated stress. Cortisol is a hormone released by the adrenal glands in response to stress. Once it gets into the bloodstream, it is responsible for relaying the news of stress to all parts of the body and mind.

Cortisol is the hormone, for example, that triggers the "fight or flight" response to stress. That allows us to spring into action when we sense danger. But like many emergency-alert systems, the stress response comes at a considerable cost. Among other effects, frequent exposure to high levels of stress hormones exhausts the body's physical resources, impairs learning and memory, and makes people susceptible to depression.

In the animal studies, vitamin C fed to rats undergoing stress not only prevented the expected increase in cortisol levels, it prevented the animals from exhibiting the known signs of physical and emotional stress, including loss of body weight. Animals that did not receive vitamin C had three times the level of stress hormones.

The present RDA for vitamin C for adults is 60 milligrams—a far cry from the 1,000 mg found helpful in the stress study. But there's a growing belief that the RDA for vitamin C is vastly outdated. The current RDA was set decades ago and is based on the amount of the vitamin needed to ward off scurvy.


That vitamin d result looks very low ....but you need reference range to be sure.

Usual ranges are - under 25=deficient - 25-50=inadequate. When taking thyroxine its recommended on here that we get Vit d up to about 100. We need Vit D for thyroid hormones to work.

Vitamin d is not really a vitamin at all, it is a pre-steroid hormone, we need it for good adrenal health, so very low vitamin d is significant.

Have you had B12, folate and ferratin levels checked. If GP / endo won't, private tests available (many of us had to go this route)

Blue horizon thyroid plus eleven test will check all these



Your 150mcg Levo isn't working for you as TSH is too high and T4 too low.

Adrenals can become compromised over years of supporting unbalanced thyroid hormone levels. Your cortisol is very low, hence proposed synacthen test.

Vit D is low ... are you supplementing ? ?

What about Vit B12, folate and ferritin ? ? ..All vital to improve adrenal and thyroid health.

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Endo wants me to start on 20,000 IU of Colecalciferol twice weekly for 7 weeks, and to take Adcal D3 once daily for maintenance after..



Good. What about other nutrients ?

There is thought that Levothyroxine should not be administered with failing adrenal health (as to speed up the bodies metabolism with T4 will further stress already failing adrenal glands so creating a bigger imbalance) without supporting the adrenal glands so both adrenal and thyroid health improve together . Also Levothyroxine requires adequate levels of cortisol to work.


Hi radd

The last lot of tests I had done via Blue Horizon came back as

B12 - 375 (191-563)

Folate - 3.4 (4.6-18.7)

Ferritin - 44.4 (13 - 150)

I have also just managed to find some of the ranges, which are TSH (0.35-4.00) and FT4 (9.00-26.00)



They are all low.

Folate (B9) works with vitamin B12 to help create and regenerate red blood cells and make iron work properly. They can be supplemented as Methylfolate and Methylocobalamin together with B Complex.

I don't supplement iron but members have found Ferrous Fumarate beneficial. Take each iron tablet with 500mg-1,000mg vitamin C to aid absorption and minimise constipation . Vit C can be increased to support adrenal glands. I take 3-4g daily of Vit C in a mixed ascorbate powder which is slightly gentler on the stomach.

Good advice re Vit D from HB below. I take D3 with K2 added.

It is important to support your adrenals glands and you may find either glandulars or adaptogens beneficial but it is important not to take anything before your synacthen test because it may skew the results. The B12, folate and ferritin & Vit D suggestions above will not effect this test result.


The Adrenal Glands & Supports


Thank you for taking the time to help me, I will look into getting what you have suggested...

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I'm never sure why doctors are so keen on Adcal D3. It contains calcium as well as vitamin D3.

Some comments on supplementing vitamin D3 and calcium :

1) Taking vitamin D3 raises absorption of calcium from the diet. Supplementing calcium when also taking vitamin D3 is only justifiable if calcium levels have been tested and found to be low. Have your calcium levels been checked?

2) Over the range levels of calcium are not a good thing. The excess calcium often ends up lining the arteries. And excess calcium can make people feel very ill.

3) The extra calcium absorbed from the diet with vitamin D3 supplementation needs to be deposited in the bones and the teeth not in the arteries. The body needs vitamin K2 to be able to direct the calcium to the right place, so this should be supplemented. Magnesium is also an essential part of the process as well. Magnesium deficiency is common. It can be supplemented in many ways. Personally I take magnesium citrate in the evening (it makes people a bit sleepy). I don't exceed the Recommended Dietary Allowance.

4) Vitamin D3 is fat-soluble. Take supplements of it with your fattiest meal of the day to aid absorption.

A general comment about D3 supplements - they are not expensive. You can get a year's supply of Vitamin D3 in 5000 iU capsules for about £10 or possibly a bit less. No prescription is required and they are easily available on Amazon or on other supplement sites.

Another general comment... Personally I prefer to take vitamin D3 in doses that I can take every day, rather than larger doses once or twice a week. I have a feeling (nothing more scientific than that!) that such large doses will increase the risk of side effects and reduce absorption, but I could be wrong.

Please note : I'm not medically trained. You take my advice at your own risk. Please do your own research.


Your cortisol result looks low to me. But the timing of it - 11am - is rather unhelpful. Normally cortisol is measured at 9am. There is a circadian rhythm to the production of cortisol. It is highest when we get up in the morning, then reduces as the day goes on. Low levels of cortisol at bedtime help the body to sleep. In the latter part of the night cortisol starts to rise - I'm not sure when the rise begins. This raising of cortisol prepares the body for the day and starts the process of waking people up.

It is due to this circadian rhythm that it makes sense to measure cortisol at one specific time. Measuring your cortisol at 11am could be expected to produce a lower result than would have been achieved two hours earlier.

To read about how the Short Synacthen Test is carried out, and what preparation you need, take a look at pages 66 - 68 of this document. (Click on the test name in the table of contents.)

You have to avoid stress which would alter your cortisol levels. Make sure that you fast before the test, and don't drink anything except water until after the test is finished. Be as calm as possible from when you wake up until after the test. Don't talk unless you absolutely have to and keep it to a minimum even then. Don't leave home late - give yourself plenty of time to get to the hospital. Being rushed will raise your cortisol. The test MUST be scheduled for 9am, re-schedule if you get sent a test for a different time. Also make sure that an ACTH blood test is included in the testing too, as shown in that link I gave above. It is often missed out, and without it the test is compromised.


Chelle. Please don't panic yet about your cortisol (or more specifically Addison's). The test is painless and as the others have said they tested your cortisol way too late in the morning. You have to have it at 9. No later. That may well explain the low level. Pm me if you want more info on the test as I had it done a couple of weeks ago. Good luck


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