VItamin d tablets - I'm confused!

Hi everyone

I'm a noob to the site (but not to TD!) I've just been told I'm vitamin D deficient (19.5!) and I've been given a large dose for the initial boost.

My doc suggested that after the boost I take a daily dose of 800iu - I've been googling and I'm not sure what the difference is between vitamin D, D2 or D3. Please can anyone recommend which is best and some suggestions as to where I might be able to buy it?

Many thanks - hopefully this will help my brain fog and I'll be able to work these things out for myself in future!

21 Replies

  • When you say you have been given a boost what do you mean exactly? Do you know what dose and for how long you will be taking that? 800 isn't going to be enough,they say 1000 is a good maintenance dose if you have vitamin d problems. The tests they do are comprised of d2 and d3 and I think the supplements that you are meant to take are d3. is a good place to start to understand more about vitamin d deficiency :)

  • I assumed the boost was a loading dose.

    I agree that 800IU won't cut it. My results were 10 and my doc asked me to take 2500 per day (this is after the loading dose when I eventually - after a long while - got my levels up close to 100). I think 800 is very outdated advice but so many docs don't know anything about it.

  • I was given this amount by my doctor. Vit D 23 low, need to take for 8 weeks then retest.

  • Thanks both, sorry I am so foggy today!

    I'm to start taking 50,000 iu for 6 days and then take 800 iu daily after that. Ive never taken vitamin D before, the doctor referred to the high starting dose as a 'boost' :)

  • Yes, fair enough - that's not a bad description. You will need a boost with levels like that. :-)

    I don't think 800IU will be sufficient as a daily dose though. It is a maintenance dose for people whose levels are good. When I was deficient it took many months (I want to say six months but to be honest I can't remember exactly how long) to get my levels up to 50ish and then another maybe six months to get up to 100.

    I guess I'm saying that my take on it is that you need to get your bloods up to optimum and *then* a maintenance dose will keep them there (but I still think 800 is too low).

    Also depends on whether or not you make other changes. If you moved to a hot and sunny place then you might not need to supplement, but if your lifestyle/habits are the same, you have to wonder what will keep your vit d from falling again once you've finished your loading dose. x

  • Is the boost necessary or should I just take the 800 as doc said?

  • Have you had your calcium checked ? if it is high in range then very high doses of vit d can send you over the top which is not good. I was prescribed 800iu and found even that small amount didn't agree with me and it sent my calcium too high. My endo would normally give very high loading dose injections but not to me. I can only take 800 for about a week then I have to have to stop for a while before taking it again. Some people cannot tolerate vit d supps at all. Personally I would stick with what you have been prescribed, if you can tolerate it then you can always increase if needs be.

  • Yes Calcium was checked and fine thank you, yes I am sticking with what the doctor said and will retest on her request in 8 weeks time.

  • I think a poster called Clutter has taken similar amounts to that in the past so she might be able to advise you better. Hopefully she'll reply to this post too. I'm deficient too at the moment and on a 5000 dose x day for 2 months to be reviewed in a few weeks time. I do think that 800 isn't strong enough though.

  • Thanks both, you've been so helpful. I wish I could move to a hot and sunny place, I always feel so well when I'm holiday ;)

  • My vit D was in the insufficient range, so not bad by the standards of many who post on here. I took 1000iU per day and my level actually dropped quite substantially. I now take 5000iU or 6000iU vit D3 per day and I'm sure it is helping my brain fog and muscle aches and pains.

  • It's really good to hear that its helping you humanbean, I am really hopeful that now I know just how deficient in iron and vitamin D I am I can get rid of all these rubbish symptoms!

    Thanks again everyone :)

  • Hi and welcome.

    I was put on a loading dose of 50,000iu for two weeks. then supplemented 1,000iu for a further 6 months only to find that I was back down to deficient again. Another loading dose of 50,000iu was given for a week and I am now taking 3,000iu daily, which just about keeps my level hovering around the 75 mark - which is the minimum result you want.

    Many thyroid sufferers find that their gut is unable to absorb the supplements they are taking so a higher dose is needed to keep their levels up - they key thing is to have regular blood tests and then supplement amounts should be tweaked according to results.

    Moggie x

  • I find around 3000iu suits me too - I take drops for better absorption - also sprays are available.

    Vitamin D testing & info here (NHS lab) -

    (should anyone not be able to get tested by their GP). J :D

  • That's great, thanks both. My GP will test me monthly until my next endo appointment in 3 months, I'd imagine there will be some dose fiddling along the way but as I'm on armour I'm fairly used to that by now ;)

    Thankyou for the welcome and I look forward to reading around the site some more, when my brain starts working again!

  • Vitamin D goes through a number of stages when absorbed by the body denoted by D1, D2, D3. D3 is what you want it's the closest to the final vitamin your body uses. You can read up on the science if you want, but in short D3 is the one to get. I buy Boots 25mcg D3 and use sunshine in the warmer months.

  • Hi Mishka,

    My vitD was <10 and I was prescribed 40,000iu daily x 7 followed by 2,000iu daily for 2 months. Level now 116. I intend to self supplement at 2,000iu until the summer and then resume again during the winter.

    Print this off & see if your GP will prescribe the recommended maintenance dose

  • Thankyou both, I've ordered some vitamin B and a holiday to Portugal! Thankyou for the link Clutter, I'll take that along to my next appointment.

    Here's to a (hopefully!) long and very sunny summer!

  • The vitamin D council, already linked by chihiro, produced a booklet which makes excellent reading. See this post by RedApple:


  • You want vitamin D3.

    My level was recently tested as 13 and I was put on 20,000 iu once a week for 8 weeks. I believe even this is a low dose by some standards.

    I also bought a daily supplement in Boots to take after the loading phase is over. It is called "Vitabiotics ultra vitamin D" and it has 1000iu of D3. It is also possible to buy the high dose supplements online via amazon: "HuxD3 20,000 IU colecalciferol".

  • I agree with Rod -look at the Vitamin D Council website they have excellent information on there about vit D and what to take etc... I was also diagnosed very low with a reading of just 3nmol..... i had two loading doses of 100,000iu of D3 prescribed by a NHS Consultant in metabolic bone diseases -so he had checked my calcium levels. -very important that this is done. I find as I cannot tolerate even English Spring sunshine without burning that I need 5000iu of D3 per day to maintain a healthy level-I take it in a oil capsule.

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