Thyroid UK
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Blood test results to check a range of things - can anyone comment on them please?

As requested, I am reposting this with the ranges added on.

I am currently taking 200mcg Levothyroxine per day.

Despite my TSH being 0.41 (range set at 0.27 to 4.20), I was experiencing symptoms of being hypothyroid. My GP requested further blood tests and the results have come back as follows:

Full blood count classed as normal

Vitamin D3 – 37 [50.00 – 140.00] My GP called this borderline and is not prescribing me vitamin D3 supplements!

Vitamin B12 – 611 [197.00 – 866..00]

Folate - 5.1 – [4.60 – 18.70]

Erythrocyte sedimentation rate - 5mm/h [1.00 – 19.00]

Glucose random - 8.2 [2.70 – 11.00] classed as abnormal so had a fasting glucose test.

Fasting glucose test - 5.3 [3.50 – 6.00] classed as normal

Renal sodium – 143 [133.00 – 146.00]; potassium - 4.3 [3.50 – 5.30]; urea - 3.7 [2.80 – 7.80]; creatinine – 61 [44.00 – 80.00]

Ferritin – 118 [130.00 – 150.00]

Thank you

4 Replies

Your ferritin is below range. Did you have your iron level tested too? Your folate is low as is your Vit D. Personally I'd supplement these three as they might help your thyroid meds works more effectively.


Are you sure the ferritin range is right? The bottom of the range is usually much lower than that (mine is 15).

I would personally go and see another doctor at the practice about getting vit D supplements, as it's best to have calcium checked first. Never ceases to amaze me how often GPs ignore results which are below range. Explain that your Levo won't work at those levels:

"vitamin D levels need to be between 50 to 70 ng/mL for thyroid receptors to respond properly. Iron also plays an important role in thyroid hormone synthesis. Thyroid peroxidase activity depends on iron; therefore, iron deficiency could lead to hypothyroidism. Ferritin levels may need to be in the range of 90-110 to achieve proper thyroid function [Source: Paoletti]."

UK vit D results are usually expressed in nmol/L, so 50 to 70 ng/mL is actually 125 - 175 nmol/L. In terms of ferritin, if you've made a mistake on the range then your level is actually OK.

I believe that this is the Paoletti research article that this is based on, but the full article is behind a pay wall:

As rosetrees says your folate is also too low, it's best to get a 5mg folic acid supplement from your GP, usually need to take for 4 months then reduce to maintenance dose. Here is some recent research suggesting below 8 should be the deficiency marker:

"Serum folate levels under 8 μg/L (or 18 nmol/L) should be considered as a decision limit for folate depletion since a positive effect on homocysteine was observed."

Since it is never a good idea to take B vitamins in isolation, I would also suggest you take a B-complex containing all 8 B vitamins, and possibly some extra sublingual B12, because taking folate will increase demand for B12.



You are correct Hampster. I made a mistake in the ferritin range and it should be 13.0 to 150.0. I appreciate the information you have given above, need to make a cuppa and read them through. :-)


If your folate or ferritin is low then you simply cannot utilise thyroxine and will still have hypothyroid symptoms

Its absolutely vital that

ferritin is over 70 (13-150)







are all in the UPPER QUADRANT of their ranges if you are going to feel well


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