The 9 Best Vitamin K Supplements of 2023, According to a Dietitian
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Now Foods MK-7 Plus K1 and MK-4 is tested for purity and potency
Verywell Fit / Alli Waataja
Vitamin K is an essential nutrient found in leafy greens and other fruits and vegetables as well as in some animal foods and natto, a fermented soy product. Gut bacteria also produce some vitamin K in the large intestine. “Vitamin K plays many important roles in our body and assists in blood clotting, bone and cardiac health,” says Ayla Barmmer, MS, RD, founder of FullWell.
Vitamin K deficiency is rare; however, some people, including those that eat a limited diet or have malabsorptive disorders may benefit from a supplement. “One of the main signs or ways to know you may be deficient in vitamin K is bruising. Vitamin K works together with vitamin D and calcium in the body to maintain balance at all stages of life, so really anyone can benefit from this vitamin,” says Barmmer. Vitamin K supplementation besides to fix a deficiency is also being explored as a way to increase bone density and heart health, but more research is needed.
There are two types of vitamin K—phylloquinone (K1) and menaquinones (K2). There are several menaquinones which are designated by a number (four to 13) that indicates the number of side changes on chemical structure of the vitamin. The two most commonly talked about and researched are MK-4 and MK-7. When selecting the top vitamin K supplements, our dietitian interviewed other registered dietitians who are well versed in vitamin K supplements and considered the form, dose, any third party or in-house purity and potency testing and price.
Vitamin K supplements are safe for most people, though it does interact with blood thinners such as Warfarin, so anyone taking an anticoagulant should discuss supplementation with their healthcare provider first.
Always speak with a healthcare professional before adding a supplement to your routine to ensure that the supplement is appropriate for your individual needs and which dosage to take.
Now Foods MK-7 Plus K1 and MK4
Best Overall
Pros
Contains K1 & K2
Vegan and gluten-free
Tested for purity and potency
Cons
Large capsule
Contains alfalfa powder
Now Foods MK-7 Plus K1 and MK-4 tops our list as a broad spectrum vitamin k supplement that provides K1 and two forms of K2 which may offer a variety of health benefits. “Each tissue of the body contains a varying proportion of vitamin K1 to vitamin K2, with the heart tissue showing a preference for vitamin K1, while bone and arteries have a preference for vitamin K2. When shopping for a supplement you ideally want one that contains both vitamin K1 and vitamin K2,” says Sharon Puello, MA, RD, CDN, CDCES, a registered dietitian and certified diabetes care and education specialist.
While K1 is the most understood and talked about form of vitamin K, emerging research suggests benefits in supplementing with K2. Menaquinone-4 (MK-4) has been studied in relation to bone health with promising results. Menaquinone-7 (MK-7) has been studied for its potential role in reducing arterial calcification, therefore this form of vitamin K may potentially help reduce the risk of heart disease.
Now Foods completes comprehensive purity and potency testing to ensure that their products don’t contain harmful contaminants and contain the amount of each nutrient listed on the label. The supplement is also vegan, gluten-free, and doesn't contain any of the top eight allergens.
Because this supplement contains all three types of vitamin K, note the capsule is on the larger size to swallow. It also contains some alfalfa powder, which may interact with certain medications, so always check with your healthcare provider before starting a new supplement.
Price at time of publication: $36 ($0.40 per serving)
Key Specs:
Form: Capsule | Type: K1, MK-4 and MK-7 | Dose: 120 mcg K1, 360 mcg MK-4, 90 mcg MK-7 | Third-Party Certified: No but strong in-house testing | Servings Per Container: 90
Healthy Origins Vitamin K2 as MK-7
Best Budget
Pros
Third-party tested
Adequate dose of MK-7
Non-GMO ingredients
Cons
Not vegan
Only contains one source of vitamin K
If you’re looking for a quality yet affordable vitamin K supplement, we recommend Healthy Origins vitamin K2 as MK-7. It provides 100 micrograms of vitamin K2 from natto, which is more than 100 percent of the adequate intake (AI) for women and 83 percent of the AI for men. We like that this supplement is third-party tested for purity, is affordably priced, and has a small amount of oil in the softgel which may enhance absorption since vitamin K is a fat-soluble vitamin.
While it only contains MK-7 (one type of K2), that may be adequate for many people, since K1 is readily available in food. “Supplementing with K2 given its bioavailability will likely be sufficient to ensure overall adequate intake,” says Barmmer.
Healthy Origins Vitamin K2 as MK-7 is suitable for those following a vegetarian diet (but not vegan as it contains beeswax). It’s Non-GMO and is not manufactured with any of the major allergens or gluten. However, if you do have an allergy, it may be wise to reach out to the company to learn more about their processes for ensuring the products are gluten and allergen-free.
Price at time of publication: $28 ($0.16 per serving)
Key Specs:
Form: Softgel | Type: MK-7 | Dose: 100 mcg | Third-Party Certified: Yes | Servings Per Container: 180
Country Life Vegan K2
Best Chewable
Pros
Certified gluten-free and vegan
Contains MK-4 and MK-7
No artificial flavors or colors
Cons
Some may not like the stevia taste
For those that have trouble swallowing pills, Country Life Vegan K2 is a good alternative. It contains 500 micrograms of K2 and is a mix of MK-4 and MK-7. This is higher than the established AI of 90-120 micrograms, but some studies suggest that higher doses from either food or supplements may be helpful for reducing risk of artery calcification.
While not third-party tested, Country Life is committed to producing quality supplements in their NSF-GMP certified facility by checking for quality and purity at each stage of the production process. This K2 chewable is certified gluten-free and vegan, and contains no artificial colors or flavors. While it doesn’t contain any added sugar, it is sweetened with stevia which may not suit everyone’s taste preferences.
Country Life is a certified B corporation that prioritizes sustainability of their people and the environment.
Price at time of publication: $ 29 ($0.48 per serving)
Key Specs:
Form: Chewable | Type: K2 as MK-4 and MK-7 | Dose: 500 mcg | Third-Party Certified: No | Servings Per Container: 60
Related:The 9 Best Vitamins for Women of 2023
Life Extensions Super K
Best full-spectrum
Pros
In house testing for purity and potency
Gluten-free and Non-GMO
Budget-friendly
Cons
Not vegan
We recommend the Life Extension Super K for its broad spectrum coverage, quality in-house testing, and budget-friendly price point. Super K contains a blend of K1, and two types of K2 —MK-4 and MK-7—giving you everything you might need from a vitamin K supplement. The softgel also contains olive oil which may support absorption of this fat-soluble vitamin. With 2,600 micrograms of vitamin K, the dose is significantly higher than the AI of 90 to 120 micrograms, but there are no known risks of higher doses of vitamin k, and absorption rates may be as low as 30 to 40 percent for vitamin K supplements.
Super K is gluten-free and Non-GMO, though it contains beeswax so is not suitable for a vegan diet. Of note, it contains a small amount of vitamin C, which is safe for most people, but always check with your healthcare provider to ensure it doesn’t interact with any medications you are taking.
Life Extension takes quality seriously by testing raw materials and the final product to ensure it contains what’s on the label. They also ensure there aren’t any harmful levels of heavy metals or microbes in the raw materials and offer a certificate of analysis for each product if you want to see it. As an NSF-certified GMP facility, their labs are regularly audited for safety.
Price at time of publication: $ 28 ($0.31 per serving)
Key Specs:
Form: Softgel | Type: K1 and K2 as MK-4 and MK-7 | Dose: 1,500 mcg K1, 1,000 mcg MK-4, 100 mcg MK-7 | Third-Party Certified: No but other strong in-house testing | Servings Per Container: 90
Related:The 6 Best Multivitamins for Women of 2023
Blue Bonnet Vitamin K1
Best K1
Pros
Third-party tested
Vegan and gluten-free
Budget-friendly
Free of common food allergens
Cons
Only has K1
If you don’t eat many vegetables, especially leafy greens, a K1 supplement may be helpful to meet your vitamin K needs. With 100 micrograms of K1, it’s an adequate amount for both men and women. Blue Bonnet’s vitamin K is a quality and budget-friendly option and is third-party tested. It’s also vegan, gluten-free, allergy-friendly, and Kosher, making it a good option for anyone with special dietary requirements.
Because it only contains K1, and at a relatively low dose, it may not be the best supplement for those looking to improve bone density or reduce risk of arterial calcification with vitamin K. The supplement itself doesn’t contain a source of fat, so it may be best taken with a high-fat food to increase absorption of this fat-soluble vitamin.
Price at time of publication: $10 ($0.10 per serving)
Key Specs:
Form: Caplet | Type: K1 | Dose: 100 mcg| Third-Party Certified: Yes | Servings Per Container: 100
Related:The Best Vegan Multivitamins & Supplements of 2023
Nature’s Made K2
Best K2
Pros
USP Verified
No artificial flavors or colors or preservatives
Gluten-free
Cons
Only contains MK-7
May not be high enough dose for some benefits
Nature’s made K2 is a good option for those looking to supplement specifically with MK-7, as this form may help reduce arterial stiffness and calcification which can help lower risk for heart disease. With 100 micrograms, it’s an adequate dose for most people to meet the AI levels, and MK-7 is known to be better absorbed and stay in the body for longer than other forms of vitamin K. However, the best dose is still unclear, and higher amounts may be beneficial.
We like that Nature's Made K2 is USP verified—a reputable third-party organization that tests for harmful contaminants like heavy metals and microbes, and ensures it contains the amount of ingredients that's listed on the label.
It’s also gluten-free and does not contain any artificial flavors or colors or preservatives.
Price at time of publication: $21 ($0.70 per serving)
Key Specs:
Form: Softgel | Type: K2 as MK-7 | Dose: 100 mcg| Third-Party Certified: Yes | Servings Per Container: 30
Related:The 8 Best Multivitamins of 2023, According to a Dietitian
Thorne Vitamin K
Best for Bone Health
Pros
Third-party tested
Contains K1 and K2
Gluten-free, dairy-free, and soy-free
Cons
Not everyone may want the high dose
Thorne Vitamin K is a quality supplement that contains a blend of K1 and K2 (including both MK-4 and MK-7). Studies have linked higher intakes of vitamin K in both forms with better bone density. In addition, more research is suggesting that MK-4—which is not as common in supplements as the other two forms—may be particularly helpful in improving bone density, especially in postmenopausal women with osteoporosis.
Thorne’s Vitamin K is third-party tested, gluten-free, dairy-free, soy-free, and as with all Thorne supplements undergoes comprehensive in-house quality testing. While this is a very high dose supplement, there are no known risks to doses at these levels and there is no established tolerable upper intake level (UL) given the fact that excess vitamin K is excreted within hours or days (depending on the form) from the body. Even so, some may not want the higher dose amount in this supplement.
Price at time of publication: $27 ($0.45 per serving)
Key Specs:
Form: Capsule | Type: K1, & K2 as MK-4 & MK-7 | Dose: 1,000 mcg K1 5,000mcg MK-4 & 90 mcg MK-7 | Third-Party Certified: Yes | Servings Per Container: 60
Related:The 7 Best Multivitamins for Men of 2023
Pure Encapsulations Pure Heart K2D
Best for Heart Health
Pros
In-house testing for purity and potency
Contains form of vitamin K aligned with heart health research
Certified gluten-free
Cons
Expensive
If your reason for supplementing vitamin k is to support heart health, Pure Encapsulations Pure Heart K2D is a good choice. It contains 240 micrograms of K2 in the form of MK-7 which some research suggests has potential heart health benefits When it comes to supporting your heart, there may also be a synergistic effect between vitamins D and K. However, more research is needed—not all studies show a benefit of vitamin D supplementation on cardiovascular outcomes. Despite this, this supplement may be a convenient way to take these two nutrients together especially if you are deficient in vitamin D.
Pure Encapsulations Pure Heart K2D is gluten-free and Non-GMO. Pure Encapsulations is a reputable supplement brand that employs rigorous in-house testing for purity and potency. Note this supplement is more expensive than others on this list because of the addition of vitamin D.
Price at time of publication: $42 ($0.70 per serving)
Key Specs:
Form: Capsule | Type: K2 as MK-7 and D3 | Dose: 240 mcg vitamin K, 25 mcg (1,000IU) vitamin D | Third-Party Certified: No but strong in-house testing | Servings Per Container: 60
Related:The 6 Best Immune Supporting Supplements, According to a Dietitian
Now D3 + k2
Best vitamin K with vitamin D
Pros
Third-party tested
Budget-friendly
Cons
Dose may not be high enough for some people
If you’re looking for a combination product to help you meet both your vitamin D and vitamin K needs, we recommend Now Foods D3 + K2. Now Foods not only does extensive in house testing for purity and potency, but it’s also third-party tested. It’s also incredibly budget-friendly.
Vitamin D is commonly paired with vitamin K2 because they work together to support bone health. “Vitamin K2 assists with vitamin D homeostasis, allowing us to maintain strong and healthy bones and help to prevent conditions like osteoporosis,” says Barmmer.
The one downside to this product is that it is a relatively low dose of both vitamins. While most people probably don’t need a high dose vitamin K supplement, some studies suggest that 1,000 IU of vitamin D may not be enough for maintaining normal levels of vitamin D for some people. A healthcare professional can give individual guidance for the best level of vitamin D for your needs.
Price at time of publication: $15 ($0.13 per serving)
Key Specs:
Form: Capsule | Type: K2 as MK-7 and D3 | Dose: 45 mcg vitamin K, 25 mcg (1,000IU) vitamin D | Third-Party Certified: Yes | Servings Per Container: 120
Related:The Best Vitamin D Supplements of 2023, According to a Dietitian
Is a Vitamin K Supplement Beneficial?
“Most people do not have a need to supplement vitamin K,” says Caroline Thomason, RDN, LDN, CDE, because vitamin K is found in a variety of foods. “Vitamin K1 is created by plants and it’s very easy for us to obtain from our diet. You can find vitamin K1 in collard greens, kale, broccoli, spinach and turnip greens,” says Barmmer. Vitamin K2 is found in small amounts in fermented foods, meat, cheese, eggs, chicken, and pork. It’s also produced by the bacteria in the large intestine. However, the following groups of people may benefit from a supplement:
Pregnant people. “Pregnancy is a vital time to consider a prenatal that contains vitamin K. During pregnancy, a baby's skeletal development demands more nutrients from maternal stores and intake and we know that vitamin K2 in particular is harder to obtain from diet alone (unless you are a big fermented food lover),” says Barmmer.
People who eat a limited diet. If you don’t eat many vegetables and eat a limited amount of animal products or fermented foods, you may benefit from a vitamin K supplement.
People who have had bariatric surgery. Bariatric surgery increases risk for many micronutrient deficiencies, including vitamin K because your body absorbs less from food.
People with malabsorptive disorders. People with Crohn’s, colitis, short bowel syndrome, or cystic fibrosis may not absorb enough vitamin K and could benefit from a supplement.
Prolonged antibiotic use. Antibiotics can decrease helpful good bacteria in the gut that support vitamin K production (K2 specifically). Chronic use—several weeks or more— may put someone at risk for vitamin K deficiency, at least until the gut bacteria is reestablished.
People Who May Not Benefit From Vitamin K Supplements
People who eat a well balanced diet. If you eat a variety of foods including vegetables and fruits, as well as some animal products or fermented foods, you are likely to get adequate vitamin K from your diet.
People taking blood thinners. “Those on blood thinners, such as Warfarin, should avoid vitamin K supplements unless advised to take them by their healthcare practitioner,” says Puello. The most important thing to consider when taking a blood thinner or anticoagulant is to consume consistent levels of vitamin K every day whether from diets or supplements.
How We Select Supplements
Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology here.
We support supplements that are evidence-based and rooted in science. We value certain product attributes that we find to be associated with the highest quality products. We prioritize products that are third-party tested and certified by one of three independent, third party certifiers: USP, NSF, or ConsumerLab.com.
It's important to note that the FDA does not review dietary supplements for safety and effectiveness before they go to market. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend.
What to Look For in Vitamin K Supplements
Third-Party Testing
Supplements that are third-party tested are sent to a lab where they are tested to ensure they contain what they say they contain and are not contaminated with specific high-risk, common contaminants. However, it’s important to note:
Third party testing does not test to see if a product is effective or safe for everyone, and it does not ensure the supplement will not interact with other supplements or medications.
Not all third-party testing is created equal. It is not uncommon for supplement companies to pay labs for certificates after conducting minimal to no testing.
The third party certifications we can trust are: ConsumerLab.com, NSF, and USP. However, these certifications are difficult to obtain and/or expensive for manufacturers, so many companies choose not to get their products tested by one of these three organizations.
Sometimes products tested by these three companies are more expensive to try to offset the cost they pay for certification.
Just because a supplement is not tested by one of these three companies, it does not mean it’s a bad product. We recommend doing some research on the reputability of the manufacturer, and calling up the manufacturer and their testing lab to determine their protocols and decide if you feel comfortable consuming the supplement.
Form
Vitamin K supplements are available in three different forms—vitamin K1 and two different types of K2 (MK-4 and MK-7). Some supplements contain just one form and others will contain a combination of two or three. Vitamin K1 is the type found in leafy greens, broccoli, and other plant foods. K2 is found in fermented foods like natto as well as some animal foods including full-fat dairy, beef, and poultry. Vitamin K2 is also synthesized in the body, primarily by gut bacteria.
Each form may play a different role in the body. While vitamin K1 is well known for its role in blood clotting and important enzymatic reactions in the body, emerging research suggests that Vitamin K2 may play an important role in both bone and heart health. However, more research is needed in this area.
Ingredients & Potential Interactions
It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included, relative to the recommended daily value of that ingredient. Please bring the supplement label to a healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking.
The main interaction concern with vitamin k is with blood thinner medications. If you take any medications, always consult with a healthcare professional before starting a vitamin k supplement.
Vitamin K Dosage
The Adequate Intake of Vitamin K as established by the Food and Nutrition Board is 90 micrograms for women (including those that are pregnant and breastfeeding) and 120 micrograms per men. However, some studies suggest that the amount needed to gain the potential bone health benefits may be higher—particularly in the form of MK-4. More research is needed to determine the best dose for each individual health outcome.
How Much is Too Much?
There is no established tolerable upper intake level (UL) for vitamin K as there are no known adverse outcomes from taking high levels of vitamin K. However, more is not necessarily better, so work with your healthcare provider to determine the right amount for you.
Frequently Asked Questions
What is the best form of vitamin K to take?
The best form is highly individualized and will depend on your diet and the reason you’re taking a supplement. For example K2 in the form of MK-4 has shown the most promise in improving bone density or reducing bone loss. When it comes to heart health, MK-7 or a combination of K1 and K2 (MK-7) may be more helpful. However results in this area have been mixed and more research is needed.
“Research has also shown that vitamin K2 is the most bioactive form of vitamin K, and the hardest form to obtain from dietary sources alone,” says Barmmer. This is likely why the majority of supplements on the market contain K2. Both K1 and K2 are important, so it may be beneficial to make sure you’re getting both forms from diet and/or supplements.
Should you take vitamin K daily?
If you’re relying on a supplement to meet your daily vitamin K needs, it is important to take it daily. In addition, studies looking at the benefits of vitamin K supplements on health outcomes typically use daily supplementation.
Which vitamin K is best for blood clotting?
“Traditionally we were told that vitamin K1 affects blood clotting, and vitamin K2 impacts bone and cardiac health. However, studies show it isn't that simple; the body converts vitamin K1 into vitamin K2 in varying amounts depending on what tissues the vitamin K is going to,” says Puello.
It’s estimated that although the majority of the vitamin K in our diet comes from K1, the body converts some K1 to K2 and both forms contribute equally to vitamin K status. While you can certainly get adequate K1 from the diet, if you’re relying on supplements it may be beneficial to take one that offers both forms.
Who should not take vitamin K supplements?
Vitamin K supplements are safe for most people. Vitamin K interacts with blood thinners (also known as anticoagulants), so anyone taking a medication for that purpose should avoid vitamin K supplements, unless prescribed by your healthcare provider. There isn’t an established tolerable upper intake level (UL) since there are no known toxicity risks, even with high doses. That said, many people do not need to take a vitamin K supplement as it’s readily available in a variety of foods and can be obtained through diet.
Should vitamin K be taken with vitamin D?
Emerging research suggests that vitamin D and K have a synergistic relationship in supporting bone and heart health, and there may be benefit to taking the two together. However, it’s important to evaluate your own needs with your healthcare provider. Not everyone needs a vitamin D supplement, and there are potential downsides to high amounts of vitamin D if you don’t need it. It’s recommended you have your vitamin D levels checked before starting a supplement.
If you’re getting adequate vitamin K through diet and do need a vitamin D supplement, there may still be a benefit to taking one with K, though more research is needed. Always check with your healthcare provider before starting a new supplement regimen.
Read Next:The 10 Best Supplements for Joint Health of 2023, According to a Dietitian
Why Trust Verywell Fit
Sarah Anzlovar, MS, RDN, LDN is a registered dietitian with her master's degree in nutrition communication from the Tufts Friedman School of Nutrition Science and Policy. She owns a private practice in the suburbs of Boston, where she helps her clients ditch diets and learn to eat foods that help them feel their best and achieve optimal health. Sarah is also a freelance writer, where she lends her expertise in translating the research on a wide variety of nutrition topics into relatable and approachable recommendations for consumers.
