The 9 Best Vitamin K Supplements of 2024, 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 vitamin K 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 the amount of 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 diet 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 contain a combination of two or three. Vitamin K1 is found in leafy greens, broccoli, and other plant foods. K2 is found in fermented foods like natto and 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. The best form is highly individualized and will depend on your diet and the reason you’re taking a supplement. 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.

"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 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.

Ingredients & Potential Interactions

It is essential to carefully read a supplement's ingredient list and nutrition facts panel to determine which ingredients are included and how much of each ingredient is included relative to its recommended daily value. 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 medications, always consult with a healthcare professional before starting a vitamin K supplement.

Emerging research suggests that vitamin D and K have a synergistic relationship in supporting bone and heart health, and there may be benefits 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. 

Vitamin K Dosage

The Adequate Intake of Vitamin K, as established by the Food and Nutrition Board, is 90 micrograms for women (including those who are pregnant and breastfeeding) and 120 micrograms for 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.

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. 

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.

Our Experts

We interviewed the following experts to get their take on the best forms of vitamin K, who can benefit from vitamin K supplements, and who can most benefit from them.

• Ayla Barmmer, MS, RD, Registered Dietitian and founder of FullWell
• Sharon Puello, MA, RD, CDN, CDCES, Registered Dietitian and Certified Diabetes Care and Education Specialist
• Caroline Thomason, RDN, LDN, CDE, Registered Dietitian, Nutrition Coach, and Certified Diabetes Care & Education Specialist

Why Trust Verywell Health

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 research on a wide variety of nutrition topics into relatable and approachable recommendations for consumers.

Shushy Rita Setrakian is a registered dietitian passionate about converting nutrition science into meaningful dietary recommendations. She has an eye for spotting the latest nutrition trends, research, and breaking down what that can mean for your supplement and food choices. Shushy received her M.S. in Nutrition Education from Teachers College, Columbia University and later established her own nutrition and fitness practice, where she helps clients reach individual goals through education and skill development. Alongside her practice, she is one of our nutrition and supplement commerce editors and spent hours combing the research on vitamin K.