What Does The Department Of Health And Social Care Advise
You should be able to get all the vitamin K you need by eating a varied and balanced diet.
If you take vitamin K supplements, do not take too much as this might be harmful.
Taking 1mg or less of vitamin K supplements a day is unlikely to cause any harm.
Page last reviewed: 03 August 2020 Next review due: 03 August 2023
Does Vitamin K2 Interfere With Blood Thinners
Debates still linger on whether vitamin K2 acts like vitamin K1 when it comes to blood clotting and blood thinners.
We can base the argument that vitamin K2 should not be a problem of blood thinner users primarily on the following premises:
- Vitamin K1 differs from vitamin K2 to some degrees in terms of chemical structures. The dietary sources of vitamin K2 are not the same as that of K1.
Vitamin K1 vs. vitamin K2. Source: Turck D, Bresson JL, Burlingame B, et al. EFSA Journal. Dietary reference values for vitamin K. 2017 15. doi:10.2903/j.efsa.2017.4780
- If we assume that all types of vitamin K do have an interfering effect, we know that vitamin K only affects one class of blood thinnersthe VKAs.
- Moreover, most blood thinners are not in the VKA class.
While the above premises sound logical, they still dont prove that vitamin K2 wont affect blood thinners at all. In fact, there are some pieces of evidence that vitamin K2 could affect VKA blood thinners .
What Are The Risks Of Taking Vitamin K
Side effects of oral vitamin K at recommended doses are rare.
Interactions. Many drugs can interfere with the effects of vitamin K. They include antacids, blood thinners, antibiotics, aspirin, and drugs for cancer, seizures, high cholesterol, and other conditions.
Risks. You should not use vitamin K supplements unless your health care provider tells you to. People using Coumadin for heart problems, clotting disorders, or other conditions may need to watch their diets closely to control the amount of vitamin K they take in. They should not use vitamin K supplements unless advised to do so by their health care provider.
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How Do Vitamins K1 And K2 Affect Inr
INR is a measure of clotting time. The lower your INR, the faster your blood clots. Conversely, the higher the INR, the thinner the blood.
An INR range of 2.0 to 3.0 is the typical therapeutic range for people taking warfarin, while a number under 1 is considered normal for healthy folk.
Long-term consumption of Vitamin K1 of 700 mcg reduced INR values from 2 to 1.5. Vitamin K2 supplementation is more potent at reducing INR and 200 mcg of K2 will reduce INR values from 2 to 1.5.
Vitamin K2 supplementation higher than 50 mcg per day requires INR monitoring by your doctor because the K2 may be undoing some of the intended effect of Warfarin.
50 mcg of Vitamin K2 is what youd get from 3 to 4 ounces of European hard cheese. This much K2 is expected to disturb INR by only about 10%, which may be an acceptable variability in your treatment. Please discuss with your doctor.
Managing a relatively steady INR while ingesting enough K2 to maintain strong bones is a balancing act that you and your doctor will have to sort out using blood tests.
You can use this tool to track INR levels.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Is There Risk Associated With These Drugs
If you take too much Warfarin, you can wipe out most of your bodys Vitamin K. This causes an artificial, drug-induced Vitamin K deficiency for both K1 and K2.
If you take less Warfarin than needed, youll protect your Vitamin K, but your blood thinning needs may go unaddressed.
Long term use of these drugs may be linked to an increased risk of bone loss as a result of chronic Vitamin K2 deficiency.
Long-term use of these drug may lower bone density and increase risk of fractures. It may also cause inappropriate calcium deposits in soft tissues like arteries, kidneys etc.
Mice that were fed K2-inhibiting Warfarin quickly developed arterial calcification. Feeding them K2 completely inhibits this effect. Whether K2 will do the same for humans needs more investigation.
If you are concerned about the effect this medication may have on your bone mineral density, talk to your doctor about testing for uncarboxylated osteocalcin or uncarboxylated GLA proteins. Both these markers are a good measure of your Vitamin K status and by extension, an indicator for bone density loss.
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How To Take It
The best way to take vitamin C supplements is 2 – 3 times per day, with meals, depending on the dosage. Some studies suggest that adults should take 250 – 500 mg twice a day for any benefit. Talk to your doctor before taking more than 1,000 mg of vitamin C on a daily basis and before giving vitamin C to a child.
Daily intake of dietary vitamin C is listed below.
- Men over 18 years: 90 mg
- Women over 18 years: 75 mg
- Pregnant women 14 – 18 years: 80 mg
- Pregnant women over 18 years: 85 mg
- Breastfeeding women 14 – 18 years: 115 mg
- Breastfeeding women over 18 years: 120 mg
Because smoking depletes vitamin C, people who smoke may need an additional 35 mg per day.
The dose recommended to prevent or treat many of the conditions mentioned in the Uses section is often 500 – 1,000 mg per day.
Can Too Much Vitamin K Cause Blood Clots
Weve learned about how blood clotting can be beneficial to our health – but its also important we know that too much blood clotting can cause serious health problems.
So this begs the question: will too much vitamin K cause blood clots? Do I have to worry about vitamin K and vitamin K2 toxicity?
According to studies, vitamin K toxicity is extremely rare. When it does occur, toxicity typically only manifests in infants. The average healthy adult shouldnt worry about experiencing adverse side effects from their vitamin K intake.
For vitamin K2 specifically, its even less likely that well consume enough to notice negative symptoms.
This is because sources of vitamin K2 are minimal, and the average western diet consists of nowhere near enough the amount of vitamin K2 our bodies need. Most of us rely on vitamin K2 supplements to consume the right amount.
That being said, certain groups may want to limit their intake of this vitamin. Anyone taking blood thinners, for example, should understand precisely how their medication interacts with vitamin K2.
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What Do I Need To Know About Vitamin K If I Am Taking Warfarin
Changes in the amount of vitamin K in the diet can alter the metabolism of warfarin . However, vitamin K does not influence the action of other blood thinners, such as heparin or low molecular weight heparins .
You should aim to keep the amount of vitamin K in your diet consistent. For example, if you normally eat two servings per day of food that is high in vitamin K content, you should continue this pattern every day. If you do not normally eat foods that are high in vitamin K, do not suddenly eat a large amount of them.
There are certain things about vitamin K that you cannot control. For instance, some medications and illnesses can lower the amount of vitamin K in your body or change how your liver metabolizes your warfarin.
Risk Factor For Cardiovascular Morbidity And Mortality
After extensive databases had been constructed for the vitamin K1- and vitamin K2-content of various food items, population-based studies were initiated to correlate vitamin K intake with cardiovascular disease. In a first survey, Geleijnse et al. demonstrated that vitamin K2 intake is inversely correlated with cardiovascular disease and mortality. Remarkably, no association was found with the intake of vitamin K1. The study was a 10-year follow-up of 4,500 elderly subjects with a highest quartile for K2 intake of 45 µg/day. These data were confirmed by Gast et al. in over 16,000 participants of the Prospect study. Because of the large number of subjects and the long follow-up period, the effects of individual menaquinones could be tested. Long-chain menaquinones turned out to have the most beneficial effects on cardiovascular disease, with a mortality risk reduction of 9% for each 10 µg/day of extra intake. These outcomes prompted us to develop a more direct test for vascular vitamin K status and obviously circulating MGP was the target biomarker for such test.
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Can You Take Vitamin K While On Blood Thinners
As mentioned earlier, warfarin and other VKA blood thinners are affected by vitamin K.
So if youre taking warfarin or any VKA blood thinner, talk to your doctor first before taking supplementary vitamin K or foods including a heavy amount of vitamin K.
How about other blood thinners?
Outside VKAs, the other types of blood thinners are not affected by vitamin K intake .
However, this information about the connections between blood clotting, vitamin K, and blood thinners usually refers to vitamin K1 , which is just one type of vitamin K.
Why You Shouldnt Avoid Green Vegetables
Two main reasons can explain why reducing your intake of green vegetables is not necessary, even if youre going through anticoagulation therapy.
Firstly, despite what you might have heard, the presence of Vitamin K in the diet helps better balance your INR. Indeed, regularly eating vegetables, particularly green ones, helps you to be less sensitive to daily variations in Vitamin K. This is explained by the fact the liver stocks some Vitamin K, because it is a fat soluble vitamin.
For example, if you eat green vegetables every day, your liver stores Vitamin K. If, one day, you have a lower intake of Vitamin K, this will have practically no repercussions. Vitamin K stored in the liver will be used. This way, you can maintain you INR as stable as possible. However, if you never eat green vegetables, you dont have Vitamin K stores, so if you eat a good amount of green vegetables one day, youll experience a peak of Vitamin K, which will then destabilize your INR.
Secondly, Vitamin Ks bioavailability depends on several factors like cultivation, storage and cooking of foods. Whats more, we only know the Vitamin K content of around half the food in the North American diet. Its therefore practically impossible to establish and respect a recommended daily intake of Vitamin K.
Note: if you are a fan of Asian cuisine and regularly eat natto , it would be a good idea to avoid it, because it contains a large quantity of Vitamin K , which can influence your INR.
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A Patient’s Guide To Taking Warfarin
Warfarin is a prescription medication used to prevent harmful blood clots from forming or growing larger. Beneficial blood clots prevent or stop bleeding, but harmful blood clots can cause a heart attack, stroke, deep vein thrombosis or pulmonary embolism. Because warfarin interferes with the formation of blood clots, it is called an anticoagulant . Many people refer to anticoagulants as *blood thinners however, warfarin does not thin the blood but instead causes the blood to take longer to form a clot.
Foods That Contain Vitamin K:
Dark green leafy vegetables have the highest amounts of vitamin K. Foods that contain vitamin K include the following:
- Foods with more than 100 mcg per serving:
- ½ cup of cooked kale
- ½ cup of cooked spinach
- ½ cup of cooked collard greens
- 1 cup of cooked broccoli
- 1 cup of cooked brussels sprouts
- 1 cup of raw collard greens
- 1 cup of raw spinach
- 1 cup of raw endive
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Blood Thinner Pills: Your Guide To Using Them Safely
The Agency for Healthcare Research and Quality offers a free booklet and a video about blood thinner medicines. Staying Active and Healthy with Blood Thinners, a 10-minute video, features easy-to-understand explanations of how blood thinners work and why its important to take them correctly. Blood Thinner Pills: Your Guide to Using Them Safely, a 24-page booklet, explains how these pills can help prevent dangerous blood clots from forming and what to expect when taking these medicines.
How Much Vitamin K Should I Eat While I Take Warfarin
Eat the same amount of vitamin K each day. Do not change the amount of vitamin K you normally have from foods or supplements. This helps keep your INR at the same healthy level.
- A big increase in vitamin K can lower your INR. This can cause dangerous clotting in your blood.
- A big decrease in vitamin K can raise your INR. This can make it harder for your blood to clot. It can cause you to bleed too much. Do not avoid foods that contain vitamin K.
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Top 10 Foods Highest In Vitamin K
Vitamin K is an essential vitamin required for protein modification and blood clotting.
Recent studies suggest that vitamin K may play a role in treating osteoporosis and Alzheimer’s and that consuming increased levels of vitamin K can help protect against cancer and heart disease.
Unless you are taking medication to prevent blood clots, like Warfarin or Coumadin, there is no known risk of vitamin K toxicity, and no reason not to eat a lot of it. If you are on Warfarin , please check the article on low vitamin K foods for a Warfarin diet.
Foods high in vitamin K include leafy green vegetables , broccoli, Brussels sprouts, cabbage, pickled cucumber, asparagus, kiwifruit, okra, green beans, and salad greens like lettuce. The current daily value for Vitamin K is 120 micrograms .
Below is a list of foods high in vitamin K. For more, see the extended list of less common foods rich in vitamin K, or view, sort, and filter vitamin K foods using the nutrient ranking tool which lists over 200 foods high in vitamin K.
Main Food Sources Of Vitamin K
|High Content||Cabbage, Brussels sprouts, spinach, kale, turnips|
|Average Content||Asparagus, avocado, broccoli, carrots, celery, cauliflower, red cabbage, cucumber, watercress, green beans, oils , lettuce , fresh parsley, leek, green peas, tomato|
So, in answer to the original question, no, it isnt necessary to avoid green vegetables because the Vitamin K they contain enables a better control of both coagulation and medication. Good to know, those who have the most difficulty managing their INR are often those who do not eat Vitamin K and green vegetables.
Our heart-healthy menus are approved by the nutritionists at EPIC, Montreal Heart Institutes Center for Preventative Medicine, even for their anticoagulation therapy patients. Why not give them a try to help plan your meals?
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What Is Vitamin K
Vitamin K is a naturally occurring vitamin. Vitamin K is primarily found in leafy green vegetables such as spinach, broccoli, and lettuce, and enters your body when you eat these foods. Vitamin K is produced by the bacteria in your intestines, and it is also in vitamin and nutritional supplements. Your body uses vitamin K to produce some of the clotting factors that helps blood clot.
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Unfortunately, depleted soils make it extremely difficult even with a clean, whole food diet, to get sufficient amounts today. Thus, many people educated on this subject choose to boost their daily intake either with the fermented form or the animal form .
Since one of the most profound effects of increasing the amount of vitamin K2 in the diet is on the health of the cardiovascular system, the next question becomes how does K2 affect the blood?
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How Much Vitamin K2 Do We Need And Do We Get Enough Of It
There is no formal recommendation for vitamin K2 intake, since the body of research about this nutrient is still growing. The Rotterdam study in 2005 showed that the average intake for vitamin K2 was 28.5 micrograms per day, and it seems to be those who consume more might be healthier. The same study showed those consuming > 32.7 micrograms per day had lower measures of cardiovascular disease risk factors than those consuming < 21.6 micrograms per day.
Clinical trials testing health benefits of vitamin K2 can use doses ranging from 50 to 300 micrograms per day. Without a formal recommendation or a universal method of testing whether someone is deficient, though, it remains to be seen how big of a worry vitamin K2 is.
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Linus Pauling Institute Recommendation
It is not clear whether the AI for vitamin K is enough to optimize the –carboxylation of vitamin K-dependent proteins in bone . To consume the amount of vitamin K associated with a decreased risk of hip fracture in the Framingham Heart Study , an individual would need to eat a little more than ½ cup of chopped broccoli or a large salad of mixed greens every day. Though the dietary intake of vitamin K required for optimal function of all vitamin K-dependent proteins is not yet known, the Linus Pauling Institute recommends taking a multivitamin/mineral supplement and eating at least one cup of dark green leafy vegetables daily. Replacing dietary saturated fats like butter and cheese with monounsaturated fats found in olive oil and canola oil will increase dietary vitamin K intake and may decrease the risk of cardiovascular disease.
Because older adults are at increased risk of osteoporosis and hip fracture, the above recommendation for a multivitamin/mineral supplement and at least one cup of dark green leafy vegetables daily is especially relevant.
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