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Vitamin D - what’s the maintenance dose?

(7 Posts)
sweetkitty Sat 17-Aug-19 08:44:28

I’ve done a search and can’t find all the good advice on here about dosage of Vitamin D. Currently taking 800iu but want to take 4000iu on top on this, anything else I should take, magnesium? Calcium?
I have been diagnosed with fibromyalgia am constantly tired and my fingers tingle a lot, was tested 2 years ago no one said it was low but I know NHS ok levels can be low.
I’m also vegan.
Any advice appreciated.

OP’s posts: |
Bettertobehealthy Sat 17-Aug-19 10:57:13

We have differing responses to supplementation. by a factor of 6 to 1.

On average , a 75kg adult will raise their blood level of Vit D by 25 nmol/l for every 1000 IU of supplement daily ... long term. It takes two to three months to reach your equilibrium level with any particular daily dose.

You really should decide what blood level you need , and then keep it there , long term. Don't let it swing up and down by stopping and starting dosing. It is a really good idea to measure your level after you have been dosing for 3 months say , to check that you have the desired response. Some people don't. It may be because of absorption problems such as IBS, coeliacs, bile/gall bladder disorder, crohn's etc. IF you do find that you have absorption problems , you could switch to an oral spray , usually found as 1000 or 3000 or 4000 IU . per puff. This will go direct into the bloodstream, and bypass the digestive system.

Your blood level should reach over 100 , preferably 120 -140 . That is the human "normal"... throughout millions of years of evolution , and it still is , most people when exposed to plenty of sunlight , throughout the year will reach that level. Indeed , some will go as high as 200 . Here in the UK , we are unlikely to do that. Sunlight is weak as compared to where we evolved, ( Africa). Here in the UK , above 50 degrees North latitude , there is no UVB radiation in sunlight for 6 months of the year. ( Mid Oct to Mid April ) so mostly our blood levels drop dramatically. Also , by using suncreams , and avoiding vit D containing foods , we further compound the problem. Unfortunately vegan/ vegetarian food contains practically no Vit D. Some items may be fortified , but by tiny amounts.

Your intention to use 4000 to 5000 IU per day should give you a blood level in the region suggested. i.e above 120 , it does however presuppose that you don't have absorption problems.
As a vegan , you could well be low , because you don't consume much , but it really does make sense to check your level , with say a blood spot test after 3 months. Here is a possibility, an NHS lab. ( ). There are others .

The UK NHS will often say that a blood level of 50 is perfectly ok. It really isn't , it is too low, although many people do have those kind of levels.

When your blood level reaches around 100 or above , you body can absorb calcium at maximum efficiency. Vit D allows you to regulate your calcium absorption to your exact requirement. Higher Vit D , does NOT mean higher calcium blood levels, it means the correct calcium blood levels. Assuming you are consuming enough calcium to absorb. IF you don't consume enough calcium, then no matter what your vitamin D level, you won't be able to take up enough. So you should check your diet , to make sure you have enough calcium in it. In most normal circumstances , we do. That is why it is not normally necessary to supplement with calcium, IF your blood level of Vitamin D is over 100. But is does depend upon your circumstances, your diet etc. IF you consume over about 1000 mg of calcium you should be ok. You body requires about 200mg every day to replace that lost by natural processes. So , in that case , your regulatory system, Vit D / PTH hormone will adjust to absorb 20% of the calcium you ingest. In people with very low Vit D , the regulatory system may only be able to absorb say 15 % of the calcium ingested, thus resulting in the bones donating calcium to the blood , to keep blood levels of calcium where they should be. In order to do that the PTH hormone rises, in a kind of feedback loop. That is when problems with osteopenia, osteoporosis , osteomalacia could possibly arise.

It would be a good idea , to check your calcium level as well, after you have been supplementing for about 3 months, i.e when you vit D level is stable. IF when tested , your calcium is normal, then that part of your endocrine system is working correctly. . IF it is higher than normal, then you should see an endocrinologist. It is very very unlikely though.

Magnesium, is a co-factor of Vitamin D , and if you don't have enough in your diet , then you should change your diet to increase , or failing that you could supplement. Magnesium oxide , is not very absorbable, so you could try , mag citrate, glycinate, ororate. Dark greenstuff has plenty of magnesium, you probably have plenty , as a vegan ? Almonds also. A typical western diet does tend to be low in magnesium. Too much Mg supplement , all at once might lead to diarrhea, so build it up slowly , if you need it.

Well I hope that was helpful..!

Here is a thread , with lots of Vit D talk , advice etc. I did post there quite a bit,

I have posted quite a lot about vit D , here in Mumsnet , just search my nickname for more , or get back to me if you need any more information.

Best of luck


sweetkitty Sat 17-Aug-19 11:54:17

Thank you @Bettertobehealthy I have been following some of your posts but last search couldn’t find anything.

I’m going to give 4000iu a trial for 3 months with magnesium, how much do you think i should take and should I take a calcium supplement as well? I am feeling awful right now so anything that improves my overall health would be great.

On a fibromyalgia FB group people were talking about vitamin K and vitamin D raising your calcium too much but you’ve said this is nonsense?

OP’s posts: |
Bettertobehealthy Sat 17-Aug-19 14:42:27


There seems to be a lot of confusion around , about vit D and vit K.
Vit K , is a group of vitamins. Lots of Vit K1 is found in greens, particularly darker greens. You are unlikely to be short of it . in fact it is in meat , liver etc as well.

Vit K2 , is a variant of Vit K1, that has been modified by bacteria. It is only made ,naturally , by bacteria. It is to be found in foods such as butter , from grass fed ( i.e. plenty of K1 ) animals. Corn fed animals will not have the same amount. Fermented soya , is also an exceptional source. Humans should ( if all is well in their gut ) make K2 in their gut from Vit K1 and their natural gut biome.

It is Vitamin K2 , that many people are referring to , when they say it aids metabolism , in conjuction to Vitamin D . The function of K2 , is to activate certain proteins that are then able to transport Calcium around the body, i.e to bones , and away from undesirable areas such as arteries. Technically is called carboxylation , which adds a 'claw' to the protein to enable it to capture calcium ions. IF you are short of K2 , then this function might be reduced.
Along with a host of other effects, Vitamin D is an integral part of the production of these transport proteins. That is why, it is sometimes thought useful to add K2 supplementation, if you are supplementing with Vit D. Vitamin K2 does not increase the likelyhood of hypercalcaemia, BUT it could help in transporting calcium to where it should be. BUT only if you are short of it. As far as I know, it is unlikely to be harmful, if you do supplement with it.
Have a look at that thread link above, towards the end of the thread , where I tried to explain more about it.

If you do supplement with magnesium, then 400 mg , of elemental magnesium would be suitable. Start with say 200 mg for a few days ,to make sure it doesn't give you the runs. ! make sure you take enough compound eg mag citrate , to deliver the desired amount of the element magnesium. Some of these supplement bottle labels are somewhat confusing, deliberately ...I think.

Only you know , if you need calcium supplement. What is your daily consumption. Have you any reason to suppose that you are short ..? Has a doctor said you have low bone density...? In general, if you make sure your blood level of vitamin D , is over 100 , then if you consume over 1000 mg per day , then you should be ok. Many people do have some symptoms of fibromyalgia , when in fact they do have insufficient calcium in their bones, ( osteomalacia ). Again , have a look at that thread above. In that I have posted a lecture by Prof Holick, about that very mechanism. IF you consider that you have been short of absorbed calcium, for a long time , then it may very well be that additional calcium would help. You will note that Prof Holick , says that IF that is your problem , that it could well take more than 3 months to show substantial improvement. Bones need time to rebuild. Again , if that is a problem for you , you should ensure that you have at least 1.2 gram daily of protein , per kilogram of your weight. That helps to rebuild bones that have become demineralised.
All very hypothetical... but getting your vit D , to 120 -140 ish .... will be a very good start... !

Best of luck, hope that is helpful.


Bettertobehealthy Sat 17-Aug-19 15:03:14

ALSO , sweetkitty.

You should find over 200 posts re Vit D of mine in mumsnet , if you go to 'advanced search' , then just type in ' bettertobehealthy' in the box marked - Posted by username , then search. I believe you need to be logged in , to do that. See if that works .

sweetkitty Sat 17-Aug-19 15:20:02

Thanks so much I’ll have a read through that thread and that link.

OP’s posts: |
honeyrider Tue 03-Sep-19 00:00:12

I've just started taking a vitamin D supplement, the dose is 25,000iu twice a week, then once a week for life. My ferritin level keep rising and it's now 378 so I've to avoid iron rich foods.

Bettertobehealthy I've learnt a lot from your posts thanks.

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