10 Vitamin K–Rich Foods That Support Healthy Bones, Blood, and More
When people think of vitamin K, they often relate it to blood clotting—and this is an accurate association because this vitamin is required in the synthesis of several blood proteins involved in clotting, says Nijya Saffo, RD, registered dietitian and owner of NK Fitness and Nutrition, LLC. Besides this, another key role of vitamin K is the activation of proteins needed for bone metabolism (the replenishment of bone tissue).
Vitamin K is the collective name of a family of compounds. "There are different categories within vitamin K," says Rayanne Nguyen, RD, registered dietitian specializing in sports nutrition. "You have vitamin K1, which is found in dark leafy greens and soybean oil, and also vitamin K2 and some others, which can be found in smaller amounts in animal products." Fermented foods also contain vitamin K2.
As a fat soluble vitamin, vitamin K from food appears to be absorbed best when there's fat or oil in the same environment. So when you're having your green vegetables, toss it in some oil to increase its absorption.
Your body treats vitamin K like a fat and stores it in your liver and fat tissues. "We can rely on our body stores a little bit more than [we can for] some of our water soluble vitamins," says Nguyen. But at the same time, your body isn't able to make enough vitamin K consistently, and relies on you getting it from your diet.
The Daily Value for vitamin K is 90 micrograms. "If someone has a disease that impacts the gastrointestinal tract, like celiac disease or Crohn's disease, they may not absorb the vitamin K from their food as well," says Nguyen. In these cases, the physician and dietitian would monitor the person's vitamin K levels more regularly and may start them on a supplement.
There are also people who need to be more mindful about their intake of vitamin K-rich foods. Since vitamin K supports blood clotting, if you are on a medication to prevent clotting, sudden increases in vitamin K intake may interfere with your medication, says Saffo. "There's no evidence that you have to stop eating vitamin K foods when you're on these kinds of medications, but you don't want to overdo it and suddenly start taking vitamin K supplements or eat large amounts of foods with vitamin K in it."
If you want to keep your vitamin K intake steady or check whether you're having enough, we have rounded up the best food sources of vitamin K below.