Vitamin D insufficiency?: Hi, my mum has an... - Thyroid UK

Thyroid UK

115,676 members134,147 posts

Vitamin D insufficiency?


Hi, my mum has an underactive thyroid and I got her to have some blood tests done and it came back that she has slightly low vitamin D at 40 (<50 is insufficient).

Now previously I had a score of 47 and I was given 20,000IU tablets to take once a week for 3 months and this successfully got me to 97. This was prescribed to me by an endocrinologist but my mum doesn't have an endocrinologist and the general rules by GP's is that they won't treat an insufficiency, they just advise you to eat more fish and mushrooms which is ridiculous as I needed to take very high doses of vitamin D to get mine up so clearly that advice isn't very effective.

My question is, is it appropriate to give my mum the same treatment I had? I already have the pills of 20,000IU in but I'm just wondering if someone with a thyroid disorders should take such high doses? Or as she's older (late 50's) and is on the verge of being prediabetic, will it effect her differently?


10 Replies

Are your pills still in date?

I think that would be ok - a lot of people on here are given high doses, and it seems fine for most. I took 9,000 IU a day for a month (63,000 IU/week), and I was fine!

Ctb567 in reply to Cooper27

Yes I bought them the other day as I came back insufficient again! I know that my body is okay with dose I had last time so I feel okay just to repeat what I did last time. Just making sure mum will be okay on the same dose

Cooper27 in reply to Ctb567

If you bought them, can I check what sort of tablets they are? Are they the liquid capsules, or are they a tablet (like paracetamol) with a bulking agent?

Ctb567 in reply to Cooper27

They are liquid capsules and they are D3

Cooper27 in reply to Ctb567

That's fine - liquid is better, we don't tend to absorb very much when we take tablet forms of D3 (it relies on good stomach acid, and Hashimotos tends to mean low stomach acid)


Presumably both you and your Mum have Hashimoto's also called autoimmune thyroid disease diagnosed by high thyroid antibodies

For full Thyroid evaluation you need TSH, FT4, FT3 plus TPO and TG thyroid antibodies and also very important to test folate, ferritin and B12 as well as vitamin D

Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies or vitamins

Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have special offers, Medichecks usually have offers on Thursdays, Blue Horizon its more random

All thyroid blood tests should ideally be done as early as possible in morning and fasting. Do not take Levothyroxine dose in the 24 hours prior to test, delay and take immediately after blood draw. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

I would be cautious about giving such a high dose to your Mum. A few people react badly to vitamin D.

Vitamin D mouth spray by Better You is good as avoids poor gut function. It's trial and error what dose each person needs. Perhaps start cautiously with 1000iu daily. If no bad reaction increase to 3000iu. Retest after 2-3 months

Once you Improve level, very likely you will need on going maintenance dose to keep it there.

Retesting twice yearly via

Local CCG guidelines

Government recommends everyone supplement October to April

Also read up on importance of magnesium and vitamin K2 Mk7 supplements when taking vitamin D

Do NOT supplement any vitamin K if you take any blood thinning medication including aspirin

Vitamin C and bones

Ctb567 in reply to SlowDragon

Hi SlowDragon, what bad side effects do people usually get from vitamin D? My mum took the dose I mentioned on Friday evening and just now she's feeling a bit ill and dizzy and has a headache. She felt fine yesterday. She is under a lot of stress at the moment so it could just be that but I'm worried I've given her a dose that's too hight now?

SlowDragonAdministrator in reply to Ctb567

Suggest you get low dose vitamin D mouth spray and try that. Build up slowly

Reaction to vitamin D is uncommon, but not rare

40 is very low, not just a bit low. As yo know, you nee dot be at lest in the high 90s. She's younger than me and doesn't need to be treated as an elderly person (LOL!). Should be OK if pills are still in date, or just buy a good vit D supplement, oil emulsion or mouth spray (highest you can get) and take multiple doses. Also need K2 and magnesium to go with it. Don't forget to retest in a couple of months



It might be an idea for you to check out what the Vit D Council says.

They are recommending a level of 125nmol/L (50ng/ml)

To achieve the recommended level from 40nmol/L (16ng/ml) check out

and scroll down to the box where it says

My level is between 10-20 ng/ml

and they recommend 4,900iu D3 daily (not possible to buy that so nearest is 5,000iu)

Important cofactors needed when taking D3 mentioned here

D3 aids absorption of calcium from food and K2-MK7 directs the calcium to bones and teeth where it is needed and away from arteries and soft tissues where it can be deposited and cause problems such as hardening of the arteries, kidney stones, etc.

D3 and K2 are fat soluble so should be taken with the fattiest meal of the day, D3 four hours away from thyroid meds.

Magnesium helps D3 to work. We need Magnesium so that the body utilises D3, it's required to convert Vit D into it's active form. So it's important we ensure we take magnesium when supplementing with D3.

Magnesium comes in different forms, check to see which would suit you best and as it's calming it's best taken in the evening, four hours away from thyroid meds

Where Hashi's is present then an oral spray is best for absorption.

Where there's no Hashi's present then a D3 softgel containing extra virgin olive oil will help the D3 be absorbed.

Retest after 3 months.

When the recommended level has been reached, then you'll need a maintenance dose which may be 2000iu daily, maybe more or less, maybe less in summer than winter, it's trial and error so it's recommended to retest once or twice a year to keep within the recommended range. You can do this with a private fingerprick blood spot test with City Assays

You may also like...