Thyroid UK
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Vitamin d3 and k2 ratio


Feeling a bit overwhelmed buying supplements. Was just wondering if anyone knew how much k2 you should take in relation with how much d3 you're taking.

My level was 20 (>25) I've been on 20,000 d3 twice a week for 4 weeks and have another 3 weeks left before I'm assuming my gp will tell me to buy my own as a maintenance dose.

(That's what they did with my dad who's been taking it for atleast 18 months now without being told he needed to take k2 also. "Coincidentally" he's just been told his recent bloods show high cholesterol.)

Anyway I would like one combined as I've gone from no medication to b12 injections d3 and folic acid. Hoping for Levo soon but already feel like I'm rattling and struggling to remember to take them.

There's just so many options and doses! The two I think I'm swaying towards are one with 5000d3 + 600mg k2


5000d3 + 150mg k2 + 29mg magnesium.

I like that there's magnesium in the second one also but is it enough? And is 150mg k2 enough for 5000d3?

Also - do I wait until my next blood test to see what my d3 is now before deciding what strength maintenance dose to take?

Thanks x

14 Replies

Your first option tbh.

20,000iu a week for a level that low is a pathetic, pitiable and ignorant on your GP's behalf. My levels were 23 - <25 being deficient and my ENDO (outranks a GP ;) ) put me on 20,000iu A DAY for two weeks then 5,000 for two weeks then a re-test.

He did fail to mention K2 though *rolls eyes* but I'd already researched it.

I'm currently taking 5,000iu d3 and 600mcg k2 a day because there's no upper limit to k2 and these 600mcg capsules worked out more cost effective. I personally would take 1x600mcg per 5-10,000 iu of vit d3.


Unfortunately different NHS areas have different protocols and a different bar for adequate levels. In other words even something like vitamin D shows the NHS is a postcode lottery

In mine it's 60,000IU of D3 a week for 12 weeks followed by 1,000-2,000IU per day. A friend of mine in another part of London was told to take 8 x 800IU tablets per day for 4 months. Then go down to 1 x 800IU per day.

In my case I researched vitamin D and spoke to another person with knowledge so sorted my deficiency out within a year by ignoring the advice of taking 1,000-2,000IU but instead doubling and even tripling the dose. My GP actually agreed I should when I pointed out this person had MS, so the advice was from those involved in the MS Society. On the other hand my friend still believes his GP and after 3 years is still deficient.

Anyway no NHS protocol I've seen mentions K2 and magnesium, and speaking to some NHS medical professionals I know, they know nothing about taking them. However all the protocols state calcium should not be prescribed unless the patient is shown deficient in a test.


But shouldn't calcium be taken with vit d because one's calcium absorption would have been affected during the period of vitamin d deficiency. I understood it like this. When there is lack of calcium in the blood, it's taken out of bones for having normal blood calcium levels. So blood test still shows "normal' calcium levels. But during vitamin d deficiency, it would have been taken out of bones. That's why pains and bones issues arise. Calcium needs to be redirected to bones while supplementing d. But if you are not consuming enough calcium rich food, nor take supplements, then how is calcium going to go to bones.

Does it make sense? It's called bone resorption.



After the war it was though that only calcium and vitamin D matter for bone metabolism. The dairy industry jumped on this and so you got the marketing campaigns which meant people thought they had to drink milk and eat cheese otherwise even as an adult they would be calcium deficient. This is still a common thought today even amongst health professionals who should know better.

It was then thought in the 80s and early 90s that the reason osteoporosis is prevalent in the West was due to the high amount of calcium rich food people consumed as even flour is fortified with calcium. However unlike with the heart disease studies they didn't chuck out countries that didn't fit the pattern, and kept doing more research.

It was then discovered that there were lots of factors including sex hormone levels, other vitamins and minerals e.g. magnesium, weight bearing exercise and how much alcohol you drink that were also important in bone metabolism in adults.

Anyway it was found you are more likely to be magnesium deficient in a Western country then calcium deficient regardless of your vitamin D status. In addition having too much calcium can inhibit iron and zinc absorption, both of which are also needed for bone metabolism.

Also some point when you have your blood tests done you would have your albumin level checked. If this is low it can indicate you have a calcium problem.


Oh dear. Looks like I know nothing. NHS says my daily need of calcium is 700 mg per day and it's safe to have a total of up to 1500 mg per day.

But do I take 700 mg per day? How do I find out? I drink a cup of milk like 4 days in a week, eat a bowlful of yogurt every day. I doubt it will be 700 mg per day. So I have recently started taking a supplement 500 mg. I intend to take it for sometime and not forever.

Looks like I should take magnisium too. My doctor says if I eat a normal diet, I don't need any of these. Just vit d.


Calcium is in a lot more foods then just dairy products which is why you will have difficulty calculating what you consume. Here is a rough guide to show you the wide range of foods it is in -

The average British person consumes far more calcium daily then they actually need. Calcium is basically chalk which is one of the elements of soil which is why it is in vegetables, meat, fish, eggs, milk, cheese and water. In short every meal you eat in a Western country will have some calcium in it. Due to the fact it is hard to work out if people are consuming too much calcium through supplements people are advised not to supplement calcium unless blood tests prove otherwise.

In regards to magnesium the NHS in lots of areas won't test for it. However it is widely reported that magnesium is one of the minerals people are deficient in due to depleted soils. With magnesium if you take too much you will end up with the runs.

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Thank you, so do you think I should take more d3 now with my loading dose or wait for my next blood test?


Stay on the D3 you are on and take the cofactors mentioned.

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Salphy When I was looking into this, my findings were


"As we explore the healing power of higher doses of vitamin D3 at the Riordan Clinic, we have found it prudent to partner the safety and effectiveness of this dynamic duo. For every 5,000–10,000 units of D3 being recommended and tested for, we are recommending 100 mcg of K2 mk7 to be sure and prevent the inappropriate calcification that higher doses of D3 alone could cause."

And from

"Dr. Vermeer recommends between 45 mcg and 185 mcg daily for adults. You must use caution on the higher doses if you take anticoagulants, but if you are generally healthy and not on these types of medications, I suggest 150 mcg daily."

I use a combo D3/K2/Vit A and it contains 2000iu D3 and 100mcg K2-MK7.

I found that most of the separate K2-MK7 supplements were 90 or 100mcg.


Thank you Susie, what was the magnesium for again? I'm getting so confused 🙈😂 is 29mg enough? I don't want the runs lol


Salphy Magnesium is one of the important co-factors of D3 as it helps your body to use it

The normal amount of magnesium in a supplement is about 350-400mg.


Btw if you take too much magnesium you will have the runs. And the amounts in the supplements you have stated aren't enough to give the average adult the runs.


Well that's a bonus haha thanks


The purpose of the runs is to quickly dump excess magnesium which your body doesn't require at that time - it prevents body levels from becoming toxic.

Also worth remembering that rarely are the amounts stated on the packaging completely absorbed due to many variable factors in play at the time, including intestinal health.


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