Thyroid UK
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vitamin d daily or weekly ? which is better?

hi,, I take my vitamin d weekly as per doc instructions. have recently increased dose from 10,000 to 20,000 a week as the former never quite got me info normal range and felt my body was lacking recently. I read a lot about people taking daily but I've always hated the muzzy head I get next day so stayed weekly but I'm wondering which is best and what others have found. thanks !!

9 Replies

Ian, it does depend very much on how your stomach copes. If you struggle with a big dose, but a smaller one doesn't trouble you, I would say take it daily. On the other hand, if it affects you whatever dose you take, then the less frequently the better. Is it possible that maybe the muzzy head is connected with the high dose?

I'm fine with 4400 daily. Not sure if I could handle 30800 in one go. It never occurred to me to take it that way, but then I am having to go it alone because my levels were VERY low (26 - bottom of range 25). My GP has never even considered my vitamin D levels - despite the fact that most people over 60 have low levels and I am definitely over 60. Or at least one of me knees is - the bad one.

We are all so different. Someone on here was made to take her whole week's Levo in one go in front of her GP because he suspected non-compliance since she was still ill.

That would probably give me a heart attack a week later! LOL!

Marie XX


the stomach isn't to bad at the mo .. just wondered if it was better for thyroid health etc or indeed absorbed better daily rather than weekly. I've googled this but can't find any info for or against. they say the half life is about a week though. have good day ! regards....Ian


I've only read one source that recommended NOT to take daily, BETTER with time in between. My dose was 15,000 every third day which worked better than when I took 5,000 daily so I do tend to agree with the prescriptions written for supplementing. I always get achy limbs when taking ANY D3 supplement. Also I feel a small lump in my jaw bone may have been caused by supplementing which makes me wonder if there is a difference in the type of D3 taken. This is called a torus if you happen to find anything unusual in your jaw bone.


I was <10 and prescribed 40,000iu daily x 7 days followed by 2,000iu daily for 3 months. No issues on either dose.


how do you feel now? did you feel low to start or was it only in looking back do you notice the difference? what's your level now ? thanks !


I was low & ill because of levo. Stopped it for 4 weeks and improved massively. VitD & folate deficiencies didn't cause any problems I was aware of and treatment hasn't made any difference I can discern. Early days though, I've only been supplementing one month. Retest in another 2 months. Thinking tho', Calf muscle & biceps look better. Not sure if that's due to weight increase when I was off levo or supplementing. Skins plumped out on face & seems less dry and more elastacy too.


yeah my skin looks better too,, face looks like I've been on holiday,, shame I still feel tired and that.


Hi One thing to consider is that vit D can cause the calcium to go over range. It is an electrolyte so then very dangerous. D has to be stopped if calcium over range. Also less importantly, but not nice, calcium can cause stones and other things in the body. After a while you should adjust to it Ok., it should be split to 3 doses a day, any way.

I have had to stop D totally as calcium went dangerously over range, if I had had the high dose I needed monthly, or 3 monthly, in stead of daily , it could have even been lethal

Also of course, being hormonal, there is the effect on thyroid levels, which are best kept even.

I hope that helps you to decide,



Whoops - I seem to have lost the reply I was writing to you!

I just said that I am currently on 10,000 a day at the moment and have no problems at all. However I do have a cast iron stomach!

20,000 a week is less than 3000 a day, so maybe you might find it better to spread the dose over 7 days.

I was severely deficient in Vitamin D (less than 10!). I only got tested because the GP wanted to shut me up banging on about Vitamin D and was quite dismissive saying it would be normal. She had the grace to apologise when she saw the result but only put me on 800 a day which was useless and barely altered the level. I changed it to 2000 and then 5000 a day to try and get it up and finally about 3 or 4 months ago I decided to start taking 10,000 a day. The GPs know I am doing this and my calcium is fine.

My parathyroid was very high when the Vitamin D was so low and it very slowly began to come down as the Vitamin D went up. However, last time the parathyroid was tested it showed an increase again so in January when the Vitamin D and calcium is tested again, the parathyroid will be done as well, just to see what is going on and if further investigation is needed. If you are battling with getting your Vitamin D up then do get the GP to test your parathyroid as well for a more complete picture if you have not already had it done.


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