Thyroid UK

Can you take vitamin D even if your test results appear ok?

My results came back for vitamin D - 51.3, ferritin - 34, magnesium -. 82. Doctor wouldn't give me the ranges saying they were fine. Anyway I bought a years supply of vitamin D tablets as I was so fed up getting a second cold two weeks after getting rid of one and now he says my results are fine. Does anyone know if it will help to still take the tablets?

10 Replies

Insist on your GP providing ref ranges. Results are largely meaningless without them. Patients are entitled to copies of their results with ref ranges or to view their medical records under the Data Protection act.

51 isn't fine, it's barely sufficient. Mine is 116 after being deficient and I'm self supplementing 5,000iu daily until the summer and will resume in the Autumn.

I think your ferritin is low. 70-90 appears to be recommended for optimal absorption of thyroxine (you don't mention this). Iron tablets can cause constipation so many here recommend floradix or spatone taken with 500mg/1000mg vitC. If you take thyroxine make sure to take it 4 hours away from iron and calcium and two hours away from other meds and supplements.

I don't know whether your magnesium is fine or not, but as most of us in UK are mag deficient I supplement with 300mg plus 15mg zinc.


I don't know if this will help, but these were the ranges I got from my last Blue Horizon test for vitamin D :

<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

And these are the ranges from my last NHS test for vitamin D :

Less than 15 nmol/L : Deficiency

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

50 – 140 nmol/L : Adequate

On that basis your vitamin D level is not exactly stunning, and I doubt very much whether you will come to harm if you supplement.

Your ferritin level, on the basis of the ranges I have seen, would almost certainly be too low.

Magnesium - sorry, can't help.

I really think you have cause to complain about not getting the ranges though - you are legally entitled to the information. If you get no joy from your doctor, try the receptionists, or better still, make a request (or a complaint?) to your practice manager for the missing information.


These foods are high in magnesium.

These aren't particularly good for the thyroid gland.

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Hi, is your magnesium 0.82? On my local results the range is 0.7-1. Mine was 0.88 which GP said is fine. However, others on the forum have said the blood test for magnesium is meaningless as there is so little in the blood and the important thing is how much there is at cellular level. No idea if that is testable.


Hi That magnesium is in its tiny range, so dangerous to take any as an electrolyte. D would be oK to take , provided the corrected calcium is swell in range. Also an electrolyte and D ,ay make it go over.

Re the colds, usually relevant to zinc. Try taking that, very safe, there is a good urine test, not the blood test but no need.Iron depends on the absorption% called transference. There are 2 tests, NHS etc , that test is the most important as if low transference you need more Iron,

otherwise oK.



I would supplement. Mine is 119 and I take 5000 or 10000 iu daily during autumn and winter and when the sun is out, so am I, without sun screen!


So glad I read this post. I had my Vit D tested and came back as 57 adequate so I assumed this was OK. Am going to have Ferritin Folate and B12 done privately. So when I have results I can suppliment as necessary, including Vit D!


I'm not sure what my levels are but they are allegedly "fine" but I always take a 5000 iu supplement anyway just in case. After swotting up on depression I have this week doubled that dose...eek!! Might just do it for a couple of weeks though.


Thanks everyone. Got ranges today from unsuspecting receptionist. Vitamin D3 - 51.3(50-125) magnesium - 0.82(0.7-1) ferritin - 34(13-150) fsh - 6.7(4-13) Jackie what do you mean by electrolyte sorry? I'll take these 5000 tablets then and see how I go. My Tsh last done was. 5.5 and I'm on 50mg on 6 days a week. And 75mg on 1 day of thyroxine as if I take much more I get speedied up racing thoughts


Some guidelines for vit d:


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