Low Vitamin D and hypothyroidism


I have been suffering from a lot of the symptoms of hypothyroidism for the past three years but blood tests have come back "normal" (TSH 2.26, FT4 14.8). However the Dr said that I have low Vitamin D (no numbers given).

I remember reading somewhere that there could be a link between thyroid takeup at the cellular level and low Vitamin D. Can anybody give me any links to published research on this?



13 Replies

  • I'm afraid I don't have the links you need but you could try searching on PubMed.

    Vitamin D is apparently a prohormone that is involved in over 300 metabolic processes. Deficiency can result in many of the same symptoms as hypothyroidism and perhaps that is due to reduced cellular uptake of thyroid hormones but I don't know. You may well find that treating the deficiency reduces or even gets rid of the symptoms.

    Do you have reference ranges for your test results? It's just that the FT4 range varies a lot from lab to lab. By my reference range, your result is right at the top of the range but it is right near the bottom of some ranges. Having the reference range may give us a better idea of your actual thyroid function.

    With your TSH being above 2, thyroid function might be something worth keeping an eye on especially if rectifying the vitamin D deficiency doesn't resolve all your symptoms.

    Sorry I couldn't be more help

    Carolyn x

  • Thanks Carolyn. The reference range for normal was given as 10-24. I'd like to find some "proper" research as the doctors I have seen don't regard me as having any thyroid-related illness because they are obsessed with the "normal" ranges, regardless of any symptoms.

  • Nothing specifically about your query. Pubmed > vitamin D deficiency + hypothyroid = (small study but it does indicate that with autoimmune thyroiditis, possibly not only a gluten free diet but boosting vitamin D levels may also be a good game plan).

    J Endocrinol Invest. 2014 May;37(5):473-6. doi: 10.1007/s40618-014-0064-y. Epub 2014 Mar 18.

    The association between serum 25OHD levels and hypothyroid Hashimoto's thyroiditis.

    Mansournia N1, Mansournia MA, Saeedi S, Dehghan J.

    Author information



    Vitamin D is shown to be a potent immunomodulator. Considering the potential role of low serum vitamin D levels in autoimmune disorder, we evaluated the association between Hashimoto's thyroiditis (HT) (with subclinical or overt hypothyroidism) and serum 25-hydroxyvitamin D (25OHD) levels in an Iranian population.


    A total number of 86 individuals were enrolled. The case group included 41 patients with hypothyroid HT (overt or subclinical). The control group comprised 45 healthy euthyroid persons. Serum 25OHD levels were measured in all subjects.



    control ratio of geometric means of 25OHD levels was 0.66 (95 % CI: 0.49-0.90; P = 0.008). There was a significant inverse association between serum 25OHD levels and HT (OR: 0.81 for 5 ng/ml increase in 25OHD level, 95 % CI: 0.68-0.96; P = 0.018). This association remained significant after adjustment for potential confounding factors including age, sex and BMI.


    Our study suggested that higher serum 25OHD levels was associated with decreased risk of HT so that each 5 ng/ml increase in the serum 25OHD levels results in 19 % decrease in odds of HT.

    PMID: 24639121 [PubMed - indexed for MEDLINE]

  • Might be an idea to have calcium level checked in case your symptoms + low d are parathyroid related. If calcium is high you need parathyroid level checked.

  • Here's some Vitamin D info. Get the lab print out of your results with the reference ranges from your doctor or receptionist. Get into the habit of doing this every time something's tested.


  • ncbi.nlm.nih.gov/pubmed/245...

    This research was done here in Crete where I live. Lots of sunshine - but lots of Hashimotos :-) First posted by Helvella on this forum....

    You can be TH1 or TH2 - and the former is not suited to VitD supplementation. I think I am TH1 but take loads of D3 daily !

  • Thanks Marz. Interesting!

  • I have been on vit D for two years now having to take the super dose twice my doc says it's more of a side effect of living in England than part of my condition so maybe emigration could be on script somewhere or a few tropical hols a year. Seriously though there are so many Brits taking vit d supplement that it can't just be classed as part of any condition . But it is a symptom of many xxxx

  • Treewade, look at my link above and you'll realise that most people in Britain are deficient in Vitamin D, and most of them neither know or understand that after taking Vitamin D and getting into the optimal reference range, they should then continue with a maintenance dose. Doctors foolishly tell the patient that as they're now in the optimal range, they no longer require Vitamin D. The patient then stops taking Vitamin D and again falls into the deficient range.

  • My docs quite good not sure if even in two years I be made if t optimum range but I'm on them forever but I read a link re lansoprrazol and wonder weather my liver function iron and vit d can all b attributed to it as I have been on lans for over 20 years due to an hiatus hernia and I feel so ill if I do more than a day without it I don't think I ll ever get off it

  • Treewade, when you were found to be Vitamin D deficient, how much daily Vitamin D were you then prescribed? And was it a tablet, capsule or liquid?

  • About two years ago almost same time I got fibro diagnosis. I was given a lot of tablets t take all at once 18 I think then after another blood test three months later had to do huge dose again then been on two 500mg calceos ever since xx

  • Chewable tablets

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