Thyroid UK
90,757 members105,098 posts

How much Vit D supplement to take?


Recent results from Blue Horizon are "all normal"

CRP. 1.20. (<5.0)

Ferritin 141.0. (20-150)

TSH. 1.36. (0.27-4.20)

T4 total. 81.2. (64.5-142.0)

Free T4. 13.10 (12-22)

Free T3. 3.88. (3.1-6.8)

Anti-thyroid peroxidase abs. 11.9. (<34)

Anti-thyroglobulin Abs. 14.2. (<115)

Vitamin B12. 571. Insufficient 140-250

Serum Folate. 19.34. (10.4-42.4)

Unfortunately I forgot about the early am/empty stomach rule for blood test and did mine about 2pm, after lunch (brainfog!!).

I have a large number of the symptoms listed for underactive thyroid by and have been convinced for several years that is my problem but my GP refuses to look at anything but TSH despite the fact that I feel dreadful most of the time.

Of all results, both private and NHS over the last year or so, the only consistent problem showing has been Vitamin D, ranging from 50-74 so I have decided to take a supplement.

My question is how much to take. I have Solgar D3, 1000iu (25ug) - could anyone please tell me how much I should be taking ? Dosage on bottle says one mealtime.

I intend to have another blood test in about a month from BH to include Vit D this time.

Thanks in advance for your time.

11 Replies


How much vitamin D to supplement depends what your vitamin D result is. 75-200 is replete and most people are comfortable around 100. As your result ranges between 50 and 74 I would supplement 2,500iu D3 daily until April when ultraviolet light is stong enough to stimulate natural vitD.

TSH would have been higher had you tested early in the morning but it is very unlikely to have been over range. NHS doesn't usually diagnose hypothyroidism until TSH is over range or FT4 below range.


I am not a medical professional and this information is not intended to be a substitute for medical advice from your own doctor. Please check with your personal physician before applying any of these suggestions.


Thank you Clutter. I just need to feel that I am at least doing something to help myself feel better not just complaining about feeling unwell with one thing or another. I will take the dosage you suggest and then see how I feel next spring. Thanks again for your support and help, you people are a godsend. 👏👏

1 like

Hi, me again. Sorry if this is a silly question but should I be taking the Vit D dosage in one dose or should it be spaced out? I've been spacing them out over the day but suddenly occurred to me that this might not be the best way.

Can you help please??


You can take it in one dose with some good fats as D is fat soluble. It is often suggested on the forum to also take VitK2 MK7 - ensuring improved calcium levels are directed to your bones and teeth.

If you would like more replies I suggest you start a new thread 😊

1 like


No need to spread it out. Take it with the fattiest meal of the day which will aid absorption.

1 like

Some years ago I was severely lacking in Vit D my level was very low at 11, I was prescribed D3 in large doses to try and boost my levels and then prescribed supplements for life and take 2000iu per day apparently it is hard to overdose on Vit D, my level recently measured was 72.84 which is the highest it has been and is in the normal range now. I am sure that if you took 1000iu per day this would be absolutely fine I do think 2500iu is quite high considering your levels are not severely depleted. You might want to ask your GP for his opinion.


Thank you for your reply Purranza, your levels were so much worse than mine!! I think I will continue with the 2500 for a while and then have another BH test done, probably before Christmas - at the proper time of day and to include Vitamin D - then decide what to do. I am very loathe to see my GP again at the moment as I feel quite angry with her😡.

I really appreciate your help and will let you know how I get on xx


Just a thought, you may want to wait a little longer than a month to re-test. It can take a while for levels to change. To improve absorption take it w some fat, either your fattiest meal or even a slice of buttered toast or similar.

If you google vit d blood spot test or similar you can find tests for around £25-30ea. I bought a quantity (they were cheaper that way) so I can monitor myself and my partner, who has some congenital bone issues.

1 like

Purranza I also had a severe deficiency (10) but my gp told me to 'go to Holland and Barrett' and buy a supplement. She also said 'everyone is deficient' as though it was nbd. It took me many months of self-treatment (after research I found out about the loading dose protocol for severe deficiency) before my levels crept up to something approaching normal. It's bonkers, I mean it affects bones and immunity, how important can it be?

1 like

Hi Puncturedbicycle most people in the Northern Hemisphere are deficient of Vit D I think that is a standard reply from GP's mine have said this. I have Rheumatoid Arthritis and the rheumatologist was testing all his patients. When my result came back he told me I was severely deficient, there were also issues with my parathyroid and he suggested then I was hypothyroid this was 5 years ago yet to get to the bottom of that one. He prescribed the loading dose (thanks for saying that as I couldn't remember what it was called) and I was prescribed 2000iu daily for life. At the beginning I had to buy the Vit D myself through Sunvit D but then it was prescribed for me each month. I think possibly had you had the loading dose you would have noticed a real difference in the way you felt, I certainly did it was like someone had turned on a light bulb whereas it probably would not be so noticeable if you gradually built it up. My Mum had rickets as a child, I inherited bone weaknesses as a child I was pigeon toed and knock kneed most likely due to Vit D deficiency, luckily Great Ormond Street (this was in the 50's) took care of me but I wonder if I had a life long deficiency I will never know of course. I have never had a reading above 74 and I guess that is now about normal for me and it is in the normal range. Too many GP's take an offhand approach to this as they do to most things gone are the days when doctors used to listen.


Well I did do a loading dose, only because I researched it and found out what to do, no thanks to the gp. Offhand I think I was on 15,000 units per day for a while and then dropped down to 2500. Even then, it took many months to get my levels anywhere good, and it took a while to find out about the thing about taking it w fatty foods. I still struggle to keep it looking ideal but I have issues w b12 as well (I do injections now) so I suspect some sort of absorption issue.

I didn't have a dramatic increase in well-being, but I did notice my hands no longer ached and their strength seemed to come back. I had had a problem w my grip (I was wearing fingerless gloves for much of the year as my hands felt so sore and feeble) and at least some of that seemed to be down to vitd.

Thank goodness you were treated as a child! I don't know when they began to take these things for granted. I guess every iteration of the nhs has one thing they focus on to the detriment of other issues. I do hope you're finally feeling better.


You may also like...