Vitamin K

Vitamin K is not one of those vitamins you hear about every day. But it plays an important role in blood clotting, bone health and more. Though you might not think about those processes often, they are foundational to your health.

While vitamin K deficiency is rare,[1] not getting enough can affect your blood’s ability to clot. This could increase risk of bleeding and negatively affect your bones. Incorporating vitamin K-rich foods into your diet can help ensure you get the optimal levels your body needs. Taking a vitamin K supplement is also a convenient option to make sure you’re getting enough.

Read on to learn what vitamin K is and all about its science-backed benefits. You’ll also learn about our approach to this important vitamin and more. You might be surprised by vitamin K’s far-reaching effects on your health.

What Is Vitamin K?

Vitamin K is a fat-soluble vitamin. That means it dissolves in fat instead of water. There are two primary forms of vitamin K: K1 (phylloquinone) and K2 (menaquinone). You can get K1 from green leafy vegetables like kale, spinach and broccoli. K2 is made by bacteria in the gut and found in fermented foods like cheese.[2]

Vitamin K is essential for the use of proteins involved in blood coagulation. It’s also vital to the proteins that help wounds heal and prevent excessive bleeding.[3] Plus, vitamin K plays a role in regulating calcium metabolism and promoting bone mineralization. This is essential for maintaining strong and healthy bones.[4]

Vitamin K Benefits

Vitamin K plays a crucial role in maintaining wellness. Here are four ways that vitamin K contributes to your body’s proper functioning:

Bone Health

Vitamin K regulates calcium metabolism. It also supports the mineralization of bone tissue, which helps maintain bone density and strength.[5] Plus, vitamin K is involved in the synthesis of a protein that binds calcium to the bone matrix. This contributes to bone formation.[6]

Skin Health

Vitamin K contributes to skin health by promoting proper blood clotting. In doing so topically, it may help reduce the appearance of bruises and dark circles under the eyes.[7] Vitamin K also supports skin elasticity. It’s essential for maintaining skin integrity.[8]

Blood Clotting

Vitamin K helps activate proteins necessary for forming blood clots to stop bleeding when you have an injury.[9] This helps your body heal wounds and prevent excessive bleeding.

Strong Teeth

Vitamin K plays a role in keeping your teeth strong. Specifically, it supports bone mineralization in your jawbone. This provides the foundation for healthy teeth.[10] Vitamin K also helps your body use calcium[11] to maintain dental health and prevent tooth decay.

Next, we explore the science-backed advantages of vitamin K. We’ll also look at its positive impact on different aspects of health and wellness.

The Science-Backed Benefits of Vitamin K

In recent years, scientific research has shed light on the many benefits of vitamin K.

Vitamin K may help manage depression in women with polycystic ovary syndrome (PCOS).[12] In a recent clinical trial, 84 women with PCOS took either 90 micrograms (mcg) per day of Menaquinone-7 (vitamin K) or placebo capsules. The study lasted 8 weeks. It found Menaquinone-7 significantly improved depression compared to the placebo.

Another study suggests vitamin K1 could help people with diabetes by supporting healthy arteries.[13] Participants took either vitamin K1 pills or a placebo for 3 months. Results showed those taking vitamin K1 had a lower chance of developing new artery calcifications. This was especially true in the heart and aorta.

And finally, the topical application of Vitamin K may speed up the healing of skin wounds.[14] This finding comes from a trial with 63 patients undergoing high-frequency electrocautery treatment. Participants received either 1 percent vitamin K cream or Eucerin cream. Patients who received 1 percent vitamin K cream showed significant improvements in wound contraction. They also had better time to full recovery compared to those using Eucerin.

The Bulletproof Approach to Vitamin K

At Bulletproof, we believe in the power of nutrient-dense foods as the foundation of a healthy diet. We emphasize eating high-quality whole foods to feed your body essential nutrients. But it can sometimes be challenging to get all the nutrients you need from food alone. We offer a range of supplements to complement your diet and support your performance and well-being.

We craft our supplements using the highest quality ingredients. This provides targeted support for areas where your diet may fall short. By combining nutrient-dense foods and targeted supplements. This can help you take control of your health and unlock your full potential.

Spotlight on Vitamin K

We believe vitamin K is so important that it’s on our list of supplements everyone should take. And, we’ve included it in a few of our products.

Our Vitamins A-D-K capsules are formulated to support your body’s needs. They combine essential vitamins A, D3, K1 and K2 in bioavailable forms. Vitamin K works with vitamins A and D to make it easier for you to get comprehensive nutritional support in one simple formula. If you’d rather chew your vitamins, try our sugar-free Vitamins A-D-K Gummies.

Another way to get your daily dose of vitamin K is with Bulletproof Greens. Packed with organic greens, antioxidants and vitamins, this blend promotes energy. It also supports immune function and detoxification. Add Bulletproof Greens to your daily routine to enhance your nutrient intake. You’ll also support your body’s energy levels and natural detoxification processes.

Our commitment to quality means you can trust that our vitamin K supplements deliver the highest standards of purity and potency. This helps you perform at your best every day.

Our Supplement Testing Standards

We prioritize the quality of our supplements. In doing so, we ensure our ingredients meet the highest standards. From sourcing to testing for purity, we leave nothing to chance. Our testing approach is rigorous and driven by science. We rely on proven methods for both ingredient and finished product testing. We work with accredited third-party labs to verify the potency and safety of our products. In doing so, we also align with FDA regulations for purity, strength and composition.

Our commitment to quality extends to every step of the testing process. We choose ingredients based on research published in peer-reviewed journals. This is to ensure each supplement is backed by evidence-based science. Plus, we analyze each production lot to assess physical and chemical properties. This guarantees consistent quality and efficacy.

Our team of food safety experts oversees an internal ingredient risk assessment process. It involves four layers of quality testing. We examine the identity, purity, strength and composition of our supplements. This is to make sure they are accurately labeled, effective and safe. This extensive process takes longer but helps us uphold the highest standards for supplements you can trust.


What are good food sources of vitamin K?

Good food sources of vitamin K include leafy green vegetables such as kale, spinach and Swiss chard. These choices are rich in vitamin K1 (phylloquinone). Vegetables like broccoli, Brussels sprouts and cabbage also have a lot of vitamin K1. Fermented foods like natto, a traditional Japanese dish made from soybeans, are high in vitamin K2 (menaquinone). And finally, you can get small amounts of vitamin K2 from animal products like liver and egg yolks.

How much vitamin K per day do you need?

The recommended daily intake of vitamin K is typically the same as the Daily Value (DV). This is around 120 mcg per day.[15] The Daily Value is based on the dietary recommendations for a 2,000-calorie per day diet. This is considered an average daily intake for many adults. However, your specific needs may vary according to your age, sex and lifestyle. Consult a healthcare professional about your situation.

What are the signs of vitamin K deficiency?

Signs of vitamin K deficiency may include increased bleeding and bruising,[16] especially from minor cuts or wounds. This is because vitamin K plays an important role in blood clotting. Other signs may include bleeding gums, nosebleeds and heavy menstrual bleeding for women.[17] If you think you might have a vitamin K deficiency, check with a healthcare professional. Your clinician can provide appropriate testing and guidance for treatment.

Does vitamin K interact with medications?

Yes, vitamin K can interact with certain medications. Anticoagulant medications such as warfarin are an example. They work by blocking the action of vitamin K in the body to prevent blood clotting.[18] Eating vitamin K-rich foods or taking vitamin K supplements while on these medications can reduce their effectiveness. Conversely, antibiotics and some other medications may reduce vitamin K in the body. They do this by affecting the gut bacteria responsible for vitamin K synthesis.[19]

Is vitamin K a good bone health supplement?

Yes, vitamin K is a good bone health supplement. It helps with bone metabolism. It does this by supporting the proper functioning of proteins involved in bone mineralization.[20] By promoting calcification in bones, vitamin K helps maintain bone density and strength.[21] Taking Vitamins A-D-K together is especially helpful. Vitamin D helps with calcium absorption. Vitamin K helps direct calcium to the bones and prevents it from accumulating in soft tissues.

What’s the benefit of taking vitamin K with vitamins D and A?

Taking vitamin K with vitamins A and D has cumulative effects that support bone health. They also support immune function and cardiovascular health.[22] Together, these vitamins promote optimal bone mineralization and density. They also work collectively to regulate immune responses and support a strong immune system. Vitamin K also aids in proper blood clotting and prevents arterial calcification.[23] This complements the cardiovascular benefits of vitamins A and D.

What should you look for in a vitamin K supplement?

Choose a vitamin K supplement that contains vitamin K2 in its MK-4 and MK-7 forms. These are the easiest for your body to use. Look for a supplement that has undergone third-party testing to verify its potency, purity and quality. Consider the dosage and form of the supplement. Choose a dose that aligns with your health needs and preferences. Select an option that suits your lifestyle, whether capsules, gummies, tablets or liquid. Finally, check for additional ingredients or additives. Avoid potential allergens or unnecessary fillers. Even better, choose a three-in-one supplement that includes vitamins A-D-K for optimal effectiveness.