The different forms and benefits of vitamin K

Vitamin K was originally called the coagulation vitamin when it was uncovered in 1929 by a Danish scientist. When his studies were published in a German journal, it was referred to as Koagulationsvitamin. Thus the name.

Without enough vitamin K you could have uncontrolled bleeding, calcification of arteries and soft tissues, and weak bones. There are different forms of this fat-soluble vitamin and each one makes its own contribution to our health. The two forms most often found in our diet are K1 and K2.

Fat-soluble means it will dissolve in fat and can be stored in our body. This allows the body to accumulate amounts of vitamin K, but it also means you can potentially get to much and reach levels that are toxic.

You can get vitamin K, in the form of K1, from cabbage, cauliflower, and green leafy vegetables such as spinach and kale. K1 is what we find in plants as it is involved in photosynthesis. Our body uses this form for it’s blood clotting properties. That is why some people using a blood thinner to prevent blood clots are asked to pay attention to how much they eat of these vegetables. This drug prevents the production of vitamin K in the liver.

Some studies are showing regular consumption of a modest amount of vitamin K1 can support the anticoagulant drug warfarin and increase it’s therapeutic benefit. But you need to monitor closely how quickly your blood can coagulate and keep it within a safe range. I read that vitamin K1 reaches the liver effectively and can help stabilize daily fluctuations of INR.

But this is not the same for the K2 form of vitamin K. K2 comes from animal products and fermented foods. We also produce it in our guts. Bacteria in the gut flora can convert K1 into K2. They will also create sub-forms, most notably MK-4 and MK-7.

K2 ranges widely in it’s benefits. Not only does it prevent calcium from depositing in your arteries, joints and kidneys but it makes sure calcium is getting to your bones and teeth where it is actually needed.

This form of vitamin K also helps you make insulin and stay sensitive to insulin which stabilizes blood sugar levels. It can increase testosterone in males and reduce it in females with polycystic ovarian syndrome. K2 also protects against cancer by suppressing genes that cause cells to turn cancerous.

K2 can be found in dark eggs, chicken meat, goose liver, and butter. The MK-4 form is most abundant here. Natto, which is fermented soybean, and hard cheeses have more of the MK-7 form. Here again, bacteria in the soy are responsible for the manufacture of K2.

The MK-7 form of K2 stays active in our liver much longer than K1 or MK-4. That means more of it will get carried to your bones. That will help with mineralization and making your bones stronger. I consider vitamin D, vitamin K2, calcium, and magnesium essential for healthy bones.

But K2, especially the MK-7 form, has been shown to increase clotting potential at small dosages. If you are taking warfarin, you would want be very careful and closely monitor your INR. Or, better yet, not take it at all. This is not the case if you are taking one of the new types of anticoagulant drugs that do not prevent the recycling of vitamin K.

MK-4 is taken up quickly by our tissues more effectively that the other forms. But it is less effective at reaching our liver and bones. This would make it more protective against calcium deposits in tissue and cancer development, as well as supporting sex hormone production.

There are reasons to be selective over which form of vitamin K you choose. But the benefits of vitamin K are worth considering. Especially when it comes to lowering risk for osteoporosis and fractures, stabilizing INR when taking warfarin, as well as reducing calcification of arteries and balancing sex hormones.

If you like to talk more, come on by.

Scott Porter, a functional medicine pharmacist, is the director of the Center for Functional Nutrition at Sandpoint Super Drug.