Is there a way to predict dosing changes if adding K to the diet?

[Protimenow]

It's a long known fact that Vitamin K is a nutrient that nobody should do without. It provides benefits, in addition to promoting coagulation (and negating the effects of coumadin/warfarin). It's also been established that for people who are getting certain levels of Vitamin K (usually through diet), once a fairly stable level of Vitamin K intake has been established, it seems to be easier to maintain a stable INR after an appropriate increase in dosage.

In the past, many of us have been advised to avoid Vitamin K - or foods that are rich in Vitamin K - so that we can keep our INRs at desired levels. There seem to be a few lines of thinking regarding K and Warfarin: Some seem to be taking advantage of the benefits of Vitamin K (and increasing the dosage of warfarin to accommodate for the effects of K), while others are convinced that we should completely avoid any sources of Vitamin K, so that our anticoagulation can be more easily regulated. There's also evidence to suggest that INRs can be more easily managed if we DO have certain levels of Vitamin K and merely increase our dosage of warfarin/coumadin.

I'm thinking about adding Vitamin K - in regulated amounts (from a supplement) - to my vitamin intake so that my body can take advantage of the benefits of Vitamin K, but I certainly don't want to make my INR plummet.

Are there any predictors or tools that can be used (that you're aware of) to know how much of an increase in warfarin is required when taking Vitamin K, so that the INR doesn't plummet?

Thanks

 

[chaconne]

To start, your method of test once a week, would seem to be the best way to see what happens, after the fact, as a result of a diet change. You could try to calibrate the effect of a known amount of additional K for yourself, and then predict what would happen if you change the intake amount. I wonder if a change in INR is linearly proportional to a change in K intake?

On a similar note, you seem to have quite a bit of experience with INR selt-testing, dosing and many types of meters. could you quatitatively show us a list of things you've done, taken or eaten that have affected your INR, and how much?

 

[Bina]

It's a long known fact that Vitamin K is a nutrient that nobody should do without. It provides benefits, in addition to promoting coagulation (and negating the effects of coumadin/warfarin). It's also been established that for people who are getting certain levels of Vitamin K (usually through diet), once a fairly stable level of Vitamin K intake has been established, it seems to be easier to maintain a stable INR after an appropriate increase in dosage.

In the past, many of us have been advised to avoid Vitamin K - or foods that are rich in Vitamin K - so that we can keep our INRs at desired levels. There seem to be a few lines of thinking regarding K and Warfarin: Some seem to be taking advantage of the benefits of Vitamin K (and increasing the dosage of warfarin to accommodate for the effects of K), while others are convinced that we should completely avoid any sources of Vitamin K, so that our anticoagulation can be more easily regulated. There's also evidence to suggest that INRs can be more easily managed if we DO have certain levels of Vitamin K and merely increase our dosage of warfarin/coumadin.

I'm thinking about adding Vitamin K - in regulated amounts (from a supplement) - to my vitamin intake so that my body can take advantage of the benefits of Vitamin K, but I certainly don't want to make my INR plummet.

Are there any predictors or tools that can be used (that you're aware of) to know how much of an increase in warfarin is required when taking Vitamin K, so that the INR doesn't plummet?

Thanks

Sure there is a tool; it's called a Home Monitor.:biggrin2:

 

[newmitral]

To the best of my knowledge there is no easy way to predict the exact INR effect, and consequent dosage change due to vitamin-k supplementation, just as there is no definitive way to predict how much warfarin dose any given person will need to maintain their target range initially. I am somewhat "warfarin-resistant" and require a high daily dose (about 12mg/day) to maintain my target range. Others can stay in range with only 4 or 5 mg/day; some with even less.

Funny you should bring this topic up, though. About 3 days ago, I started taking a new vitamin K supplement to try to stabilize my very erratic INR, and to also get some of the known benefits of vitamin K2 (MK-7). My INR has been very erratic, and can go from 2.5 to 4.6 in one week and back to 2.5 the next week, with nothing I can correlate it to. Based on reading several articles that recommend supplementing with a regular amount of vitamin K to stabilize hard to manage INRs, I had previously been taking a Centrum (silver) which contains "Vitamin K - 60 mcg", although which version of "K" is unspecified. After 4 months of that supplement, my INR remains as erratic as ever. I home test and have two different meters that have both confirmed the test readings.

I just switched to taking Jarrow Formulas MK-7 (available on Amazon), which has 90mcg of K2 (MK-7) form derived from Natto, which is touted as the best type to take. With the higher daily dose of vitamin K, I'm hoping my INR will stabilize a bit.

I'm not taking any chances, however, and will be testing my INR at 3 to 4 day intervals for a while to make sure the higher vitamin-k2 dose does not drop my INR too much. My first INR test after being on the increased K2 supplement for 3 days will be tomorrow morning. I will try to post tomorrow to indicate whether there was a dangerous or dramatic shift in my INR that can be attributed to the higher vitamin K supplement.
I should note that with my history of erratic INR, it may be difficult to attribute any change specifically to the supplement change without having a few months of new tests to gather statistics. I'll also see what changes in my warfarin dose are required long-term to maintain my INR in my target range.

While reporting on my own INR/dose changes may be interesting for comparison, I suspect everyone's metabolism is somewhat different. I would recommend that if you are going to try a vitamin-k supplement that you test more frequently than once a week, at least initially, to make sure your INR doesn't go out of range for long.

 

[Protimenow]

I'm using my home monitor - testing with my InRatio - more often than weekly, because my INR dropped below range. The 10% increase in dosage didn't lift me into range, so I'm upping it again - with a bigger increment today (my meter gave me a 2.2, and I suspect that, accounting for error, it may be closer to 1.9 or so). At this point, I'd feel safer with a reported INR at or above the high end of my range than I am at the low end. (I'd rather be a little bit above 3.5 and cut back than to stay below 2.5).

I plan to get some Protime cuvettes next week, and will carefully compare the INRs obtained from both meters. By that time, though, I expect to have my INR safely mid range.

 

[Protimenow]

To start, your method of test once a week, would seem to be the best way to see what happens, after the fact, as a result of a diet change. You could try to calibrate the effect of a known amount of additional K for yourself, and then predict what would happen if you change the intake amount. I wonder if a change in INR is linearly proportional to a change in K intake?

On a similar note, you seem to have quite a bit of experience with INR selt-testing, dosing and many types of meters. could you quatitatively show us a list of things you've done, taken or eaten that have affected your INR, and how much?

I have nearly three years of records - on three different types of meters. My first meter was the ProTime Classic and ProTime 3 -- possibly the most accurate. I also used the CoaguChek S (which has been discontinued and is no longer supported by Roche, but seemed to deliver INRs that, the few times I tested, pretty closely matched the ProTime). I'm using the InRatio (and now, the InRatio 2).

When I get a chance, I'll go through my "INR Diary' and see if I can pinpoint things that made changes in my INR. One thing for sure, and others have also pointed this out, was the use of antibiotics. I will see what else I can find that suggests (but can't prove) what things may change an otherwise stable INR.

 

[newmitral]

I took my INR reading this morning after having taken the new Jarrow 90mcg vitamin k2 supplement for the past 3 days. Although my INR is a bit below last week's reading (2.6 versus 3.1) , it is still within my target range (2.5-3.5), and the drop is not any bigger than the usual weekly variations I've typically been seeing since I started the warfarin regimen about a year ago.

So, in my particular case, the 90mcg daily vitamin k2 supplement seems to have caused no dangerous drop in my INR. It remains to be seen whether or not it will help to stabilize my highly varying INR. So far, my "personal best" is 5 weeks in a row before going out of range on either the high or low side - while my warfarin dose remains in a very tight range between 12.0 and 12.5mg/day.

Your mileage may vary.

 

[Bill B]

This is totally individual. Change-measure-change some more-measure some more. It's not even linear (2x change in dose does not lead to 2x change in result).

 

[Protimenow]

Right. It's definitely an individual thing. I've upped my warfarin dose to accommodate for a drop in INR (plus, I'm working as if my meter is reporting a result that is considerably higher than my actual value). I'm testing every few days, until I get a handle on the K/warfarin thing. (I was going to stop the K, but was talked out of it). I'm thinking (and it could be other factors that effect this) that I AM seeing some improvements in other areas, perhaps because of the K in my system. I'm planning to regulate my K and warfarin doses so that I am in range, and still taking Vitamin K.

 

[TheGymGuy]

I have posted this before, but seems that topping off your K reserves keeps variations in K from affecting your overall INR. I take a multivitamin with 80mg of K once in the AM and once in the PM. I generally have veggies daily. Though, most are pretty low in Vit K. Love the string/green beens.

 

[normofthenorth]

Is Warfarin a K2 inhibitor/antagonist as well as a K1 inhibitor/antagonist? If not, then K2 shouldn't affect INR. I thought the logic of K2 supplementation was that it's Good For You and especially Good For Us. And that the logic of K1 supplementation was basically that it's easier to balance a 2-pan balance when there's more than zero weight on each pan. In other words, the benefit of K1 supplementation is primarily BECAUSE it's directly opposed to the Warfarin, making it easier to stay in balance.

Either way, I can see a case for K2 supplementation. But if Warfarin doesn't munch on it, then the K2 won't help with the stabilization.

 

[newmitral]

Most of the studies I have previously found just talk about "vitamin-k", but this one:

http://www.ncbi.nlm.nih.gov/pubmed/10347843​

specifically calls out Vitamin-K2. The key sentence in the abstract is:
"The blood coagulation time was markedly prolonged by (warfarin) treatment for 7 days and this effect was completely inhibited by all doses of K2."

So, it would seem that K2 is a warfarin antagonist similar to K1.

As mentioned, I had previously been taking a multivitamin with 60mcg of K1 in an attempt to stabilize my INR, but after 6 months, with test readings each week, my statistics are:
Mean INR = 3.05 (target 2.5-3.5)
Standard Deviation = 0.63 (generally INR is considered unstable if SD over 0.5)

I have never gone more than 5 weeks before going out of range either on the high side or low side, with very little change in warfarin dose. It takes between 12.0 and 12.5 mg/day to get me in range, with the occasional holding of 1 day's dose when my INR shoots up over 4.5. So, it's not a roller-coaster created by dosing changes, it has to be something in my diet or metabolism that's causing the fluctuations.

My diet is generally thin on veggies, but it is pretty consistent, as is my exercise routine. Nevertheless, the 60mcg K1 supplement has not stabilized my INR.

The new supplement, 90mcg of K2 which I am taking INSTEAD of the multivitamin with 60mcg of K1, is a higher daily dose, and from the single test so far, does not seem to significantly drop my INR, but then again, neither did the K1. I plan to get at least 3 months of weekly INR measurements before concluding whether my INR is more stable with the 90mcg of K2, or not. If not, I will up the amount of K, either by taking BOTH the K1 and K2 supplements, or by increasing just the K2 dose.

For obvious reasons, I will be taking things very slowly and carefully to ensure that my INR remains within range as much as possible. But, I'll post back on whatever findings I reach.

 

[TheGymGuy]

newmitral, this is a very interesting link to the study at NIH, of course there are also many others stating that having a certain amount of K per day would help stabilize INR to otherwise less stable patients.

I like your approach to monitoring your INR and all the data you have provided. Please keep on updating this, I am very curious about your results.

 

[Protimenow]

I've thrown some challenges in my path towards having a consistent INR. I started taking a K supplement, but have also been taking an antibiotic because of some dental issues. BOTH the Vitamin K and the antibiotics can have an effect on my INR. I'm not even going to bother to guess what effect that either or both will have on my INR.

Instead, I'm testing every three days, planning to keep the INR reported by my InRatio somewhere between 3.0 and 4.0 (or so). My meter seems to report higher than actual INRs, so a 3.0+ gives me confidence that I'm within the 2.5-3.5 window. When I'm finally off the antibiotic, I'll again do the testing every three or four days until I'm confident that my dose is correct.

It's nice to have a meter -- even if it does ALWAYS seem to report high.

 

[Lynlw]

Is Warfarin a K2 inhibitor/antagonist as well as a K1 inhibitor/antagonist? If not, then K2 shouldn't affect INR. I thought the logic of K2 supplementation was that it's Good For You and especially Good For Us. And that the logic of K1 supplementation was basically that it's easier to balance a 2-pan balance when there's more than zero weight on each pan. In other words, the benefit of K1 supplementation is primarily BECAUSE it's directly opposed to the Warfarin, making it easier to stay in balance.

Either way, I can see a case for K2 supplementation. But if Warfarin doesn't munch on it, then the K2 won't help with the stabilization.

Warfarin is an antagonist for ALL the forms of vit k and it affects it everywhere in the body Vit k is needed, not just the liver.

 

[Gail in Ca]

When I got 2 shots in the ER of Vit K, it brought down my INR very quickly! Not sure even what the dosage was. Usually, when starting a new supplement, I am just asked to test more frequently at home to make sure my INR stays in range.
Why take more than the recommended daily allowance of K?

 

[hook]

I added vit K2 to my diet and noticed very little dosage change needed. I chose the K2 because it is suppose to help sequester the calcium in the pluming and transport it to the bones. The logic here his it helps prevent calcium build up in the arteries and strengthen bones; bone density has been a concern for Counadin users long term. For me the K2 seems to have little or less affect than regular fit K. I pretty much eat what I want with no regard for regularity without incident; I have not gone out of range in the two years I have been on Coumadin.

The only thing that may cause my numbers to hit the low side of my range are the weeks that I travel for work. I tend to eat a lot more spinach and salads when eating on expense account. Even then there is not big fluctuation. I simply pop and extra 2.5mg and all is good.

 

[Protimenow]

I've written a little about this on other forums, but thought I'd bring it to this thread about Vitamin K. With my recent stroke in April (and, fortunately, I think I've fully recovered), I wanted to add Vitamin K to my daily regimen, in the hopes of being able to maintain a steady INR that is always in range. I've doubled my dose of warfarin, but my meter still shows me at the bottom of my range. I don't think it's time to panic about an INR below 2.5.

My meter seemed to have been reporting INR that was higher than lab values. If this is the case, my INR is still close to 2.0 - which is not a pleasant thought. In the past, I suspected that Quercetin - which I've stopped taking - also fooled the meter into reporting about .6 higher than actual. In short, I'm not sure that I trust my meter - except to believe that it's consistently reporting higher than actual results - but I don't know HOW MUCH higher than actual. I even wanted to test the idea that INR drops more shortly after taking Vitamin K than it does 12 or more hours after taking K (which sort of makes sense, because it's faster acting and doesn't have effects as long as warfarin). This didn't seem to be the case.

I'll stay at 2X my 'usual' dosage - and retest. If I'm still showing 2.5 or less, my dose will be upped even more until I'm safely in range. (Maybe I shouldn't wait to go from 15 to 20?).

Because I don't fully trust my meter, I've finally ordered some ProTime cuvettes. The one time that I compared the ProTime to the lab test, the results were almost identical. The method used by ProTime actually moves the blood around inside the 'strip,' and reports when the blood flow slows to a certain level. It may be more accurate than measuring electrical resistance, like other meters do. It's also similar to a lab test used in hospitals and clinics. I'm inclined to trust it more (and no, I have no financial relationship to the company that makes the ProTIme meter). It would be nice if the ProTime was faster, quieter, and didn't take as much blood as the newer meters.

When I finally get the cuvettes, I'll do some parallel testing and see if the meters agree. Either way, I'll record - and report - the results.

 

[Protimenow]

I stopped taking the Vitamin K supplement (Super K, from Life Extension). I got tired of worrying that my INR was below 2.0, no matter how much I increased my dosage. I realized that the effects of the K will drop more quickly than the spike in INR that I'd have after getting the K out of my body. Tonight my INR was 4.5 (or, if I believe that the meter is reporting somewhat high, possibly about 3.9 or so). I'm not worried about the INR being so high.

I just looked at the bottle of Super K --- 1000 mg of K1, 1100 mg of K2. No wonder I couldn't take enough warfarin.

Next week, when I get my ProTime cuvettes, I may start with K again -- but go with much lower dosages - and see if I can more easily adjust everything so that I'm getting K PLUS staying in range.

 

[newmitral]

Hi Protimenow,

I don't mean to sound overly harsh, but most folks would read the label to find out what is in the supplement BEFORE taking it. When I was investigating vitamin K2 supplements, I looked at the "Life-Extension Super-K" and quickly ran away from that one to purchase another brand with a more reasonable amount of K2.

To correct the info you posted, the Life Extension Super-K has 1000 mcg of K1 and 1100 mcg of K2, not 1000 mg K1 and 1100 mg K2.

The difference between a mcg and mg is a factor of 1000, with 1mg=1000mcg.
I think this distinction is important for others reading this thread, who might be looking at various supplement options.

The 2100mcg (2.1mg) vitamin K total you were taking is about 20 times the USDA daily recommendation, and is approaching the range given by emergency rooms (10mg) to quickly counteract the effects of warfarin for patients with dangerously high INR. It seems foolhardy to take such a large dose of vitamin-K when you are on warfarin, especially when all the papers referenced regarding vitamin-k and warfarin suggest doses around 100 mcg or so. These lower doses, in the 100 mcg range, are consistent with getting the benefits of K2 and shouldn't prevent you from keeping your INR in range, with only a modest increase in warfarin dose.

I did speak with my doctor about the K2 supplementation, hoping to get more info from him about k2 and warfarin interaction. Actually, he was surprised to hear of the suggestions to take regular vitamin K supplements to stabilize erratic INR, and I had to show him the medical journal references. After reading about it, my doctor was all for it, and is interested in seeing the effects it has on my INR stability. BUT, I'm taking the low dose (90mcg) daily vitamin K2 supplement. I may go up to 100mcg or even a bit higher, but would certainly not want to go much above 150mcg/day.
I'm only about 3 weeks into my vitamin K2 supplementation project so far, and it appears I may have to up my warfarin dose by about 5% or 10% to stay in range, but this is still a preliminary estimate.

For others who might be considering adding K2 for health benefits and INR stability, it is likely OK as long as you stick with a reasonable dose for the vitamin. I also recommend reading the labels and speaking with your doctor BEFORE embarking on the supplement regimen.