Does Vitamin K2 cause blood clotting??

Hello everyone! Recently I was advised on here what amounts of Vitamin D to take and also to take K2 at same time to point the D in the direction of bones etc and not end up in my arteries. Would that be the reason why a recent BH fingerprick blood test wouldn't work due to clotting - have had two lots of testing equipment sent to me but cannot get my blood to flow into the tube despite doing everything suggested in the test instructions!

I did a BH test a few weeks ago before D2 and that one worked first time. If it's not the D2 causing it, what else could it be?

Thanks for any suggestions xx

17 Replies

No, it's vit K1 that causes blood clotting. Not the same thing at all. But, when you're hypo, you do tend to have thicker blood.

Why are you talking about D2? Did you mean to say K2? :)

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Sorry Greygoose, yes I meant K2 - the same thing happens when I try to speak, go to say one thing and something completely different comes out of my mouth 😳. I take 100ug K2 (one capsule) with 3000 iu Vitamin D, is this too much do you think ? Just a bit concerned at the way my blood clotted. I have a really painful left leg at the moment, feels like an elastic band around it and moves from my groin gradually to my calf and then back up - I know it's daft but I have visions of a large clot moving around!

Any advice?? Thanks


No, that's not too much, and won't be causing your blood to clot.

I'm afraid I don't have any ideas about your leg pain, though. Perhaps a trapped nerve? I don't know.


It's worth getting a holistic minded chiropractor to check for misalignment or trapped nerves. Al least you know if it's mechanical.


Check with your doctor. You will experience pain when you have blood clots. It's best to rule that out first. I had terrible chest pain and was finally diagnosed with 2 blood clots in my right lung. Better safe than sorry.

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Depressednanny I did a bit of detective work into this a little while ago and posted about it here

However, when I did my very first finger prick test I had trouble with blood clotting almost immediately and had great difficulty getting it down into the tube. I thought I'd never be able to do another one!

I've since done 3 further fingerprick tests very successfully and this is what I do now:

I make sure I'm well hydrated, drink plenty of water the day before and before I do the test.

I have a bowl of very warm water to hand (as warm as I can stand it), use this to warm my hand up immediately before the fingerprick, I make sure my hand goes red. If blood slows down I re-warm my hand in the hot water.

I find that pricking my finger on the side near the nail bed is the best place and I use my middle or ring finger.

I stand on a stool so that I am higher than the container the blood goes into therefore my arm is straight.

If blood flow slows down I gently milk my finger. I use a second finger if necessary.

Also, I have found that despite K2 not being the form of Vit K responsible for clotting I leave my D3/K2 combo off for a week before doing the test.


Regarding D3, I have also been taking a higher dose of 5,000 plus K2 thinking I would be helping my immune system and joints, but then a survey came out very recently saying supplementing with D3 if over-hyped and in fact can cause the bones to fracture more easily as we get older. I am so confused.


Joyia Who carried out the survey?

Did you test your Vit D level before starting supplements? What was it?

Are you re-testing once or twice a year to ensure you stay within the recommended level of 100-150nmol/L?


Sorry not sure who did the research, it was a large article in the Daily Mail. Yes I do check my levels occasionally. Thanks for your response.


I've just found the article on Daily Mail online. And typically some important information has been left out.

The article acknowledges that

Current NHS guidelines say anything under 15 nmol/L is 'severe deficiency' and a level of 15-30 is regarded as 'deficiency'


From 50 to 100 is 'adequate' and 100-150 is regarded as 'optimal'

(which is what is always advised on this forum)

Then they go on to say

In the U.S. a reading over 125 (which the NHS says is 'optimal') is regarded as actually being too high — with 'potential adverse effects', says the National Institutes of Health.

Unfortunately, they omitted to say that the units of measurement in the US are ng/ml and not nmol/L.

To convert a test result measured in ng/ml to one measured in nmol/L, you need to multiply the ng/ml number by 2.5. So the reading of 125 which they are referring to, being ng/ml, when converted to nmol/L to give an accurate comparison would be 312.5nmol/L so yes, that would be far too much as toxicity level is referred to as being 220nmol/L and above.

So, as usual for a Daily Mail health article, it needs to be treated with the respect it deserves - to be used as tomorrow's chip paper or, as my old grandad used to do back in the 1950s, rip it into squares for toilet paper.

For accurate and reliable information about Vit D, we can do no better than use a respected website such as the Vit D Council - it clearly states the units of measurements used in the US and elsewhere in the world, and gives tables for how much to supplement to achieve various levels.


Thank you so much for locating the article and giving it your attention, this is very helpful.


sorry not if but should have read "is"


In regards to your question about vitamin K2 clotting blood you are correct . Vitamin K in any form does clot blood. I was taking a K2 supplement and suffered a blood clot in right coronary artery and had top have an emergency cardiac stent placement. All other arteries were clear and it was not plaque. It was just a fresh blood clot. When I discussed this with the cardiologist he said that it probably contributed to the clot. I will not take any form of vitamin K2 or any other K supplement ever again. He informed me to stop taking it. If you look it up you will find any form vitamin K causes clotting. It increases the fibrinogen level in your body and if you are prone to clotting it can be dangerous. I would suggest having your fibrinogen level checked. My was high with taking the K2. It is now back to normal limits.

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So sorry you have had a clot, and I find it very interesting you what you have said.

I have bought a combined Vit D/K2 supplement in the form of drops but I have not used it yet as I wondered about the K2 and whether it actually thickens the blood.

I will have to research the fibrinogen connection.


I was just wondering lucylocks whether you did research "the fibrinogen connection " and whether you decided to take Vitamin K2 or not ?

Like pablegalrn11 my friend in England has just this week been advised by her Consultant not to take Vitamin K2 because of blood clot risk .....which I find a bit worrying. 🤔



I did look in to it but it was all a bit confusing for me.

I decided not to take the Vitamin K2 for now.

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Thank you for replying lucylocks .😀

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