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Thyroid UK
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Vitamin d deficiency


Just need some advice been feeling really ill for the past two months dizzy spells, feeling sick, vague like I'm in a fog, keep forgetting stuff and constantly exhausted. My gp finally did some bloods and apparently I'm deficient I'm vitamin d. What I want to know is there a link between this deficiency and the thyroid.

my sister had thyroid cancer and my other sister and my dad are all on thyroxine but my blood test as come back normal. My elder sister was just told by her gp that she is deficient in vitamin d. I feel like no one is listening to me because I feel rubbish Should I ask for another blood test.

Thanks in advance

5 Replies

The short answer is yes, and others will reply on this, but it is also possible to feel as you do simply from a vit D deficiency - my neighbour spent two years feeling like this before the GP did the D test and now, D replete, she is right as rain. She has no thyroid issues.

Can you ask your surgery for a print out of your thyroid test results and print them here?


Hi ellatucker

The first thing to do is get a print-out/copy of your blood test results from the surgery with the ranges. (we are entitled to copies) and post them on a new question if you've not got them today. Vitamin D deficiency can cause symptoms. Did your GP give you a prescription for Vitamin D? Usually, if we are hypothyroid our other vitamins can be low, i.e. Vitamin B12, Vit D, iron, ferritin and folate and I hope your GP did the others besides Vit D.

The fact that hypothyroidism runs in the family could mean that although your tests may be classed as 'normal', your clinical symptoms haven't been taken into account.

Some doctors only request a TSH blood test (thyroid stimulating hormone which tries to flag up more hormones if yours are failing). TSH isn't sufficient, you also need a T4, T3, Free T4 and Free T3 particularly as hypothyroidism runs in the family. He may not agree to these and the ones he doesn't you can have privately. There is a list of labs which we can provide.

Always, from now on, get a copy of your blood test results for your own records and to post if you have a query.


Ask if GP tested for thyroid anti-bodies too (the most common form of thyroid problem is caused by anti-bodies attack your own thyroid - this is called Hashimoto's and often runs in families)

If he didn't test ask nicely if he could do anti-body test on next blood test - especially if your family members with thyroid also have Hashimoto's



Got my blood results gp wasn't happy I asked for them saying my thyroid test is normal.

Here they are

Tsh 1.68 miul 0.38-5.5

Vit d 24.8 nmol/l

Ferritin 164 ng/ml 22-322

B12 334 ng/l 211-911

Hope this makes sense


Your Vitamin D result is far too low. I know that people should only use the reference ranges for the lab that did the tests, but just for comparison the reference range for Vitamin D that I last got from an NHS lab is :

Less than 15 nmol/L : Deficiency

15 – 50 nmol/L : Insufficiency (consider supplementation)

50 – 140 nmol/L : Adequate

From Blue Horizon for vitamin D I got this reference range.

<25 nmol/L : Severe Vitamin D deficiency

25 – 75 nmol/L : Borderline ranging to insufficiency

75 – 200 nmol/L : Optimally replete

>250 nmol/L : Possible toxicity, if sustained

I feel best when my vitamin D is around 100 nmol/L.

With a level as low as yours you should be taking 10000 iU per day for a couple of months, then you should re-test, and should be able to reduce to 5000 iU per day if your vitamin D level has increased enough. But I'm not an expert on vitamin D dosing, so hopefully someone else will pipe up.

Your ferritin seems to be just about perfect (it's mid-range), although it would have been nice to get full blood count and iron panel done too, in case inflammation is artificially raising your level.

Your B12 is too low. The NHS won't treat you for this because your result is well inside the reference range. Most people feel at their best when there B12 is right at the top of the reference range or even over. Unlike some vitamins and minerals, B12 is not poisonous and any excess should get excreted in urine. You should treat yourself with methylcobalamin. I use Jarrow Formulas methylcobalamin which you stick in your mouth and just let it slowly dissolve. Don't chew it or suck it. Buy 5000mcg tablets and take one a day. When you've finished the bottle reduce to 1000mcg per day to help maintain your levels.

Your thyroid may be fine, or might not be. It's really impossible to say on the basis of just a TSH test. But getting your B12 and vitamin D levels up should make you feel a lot better.


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