What Is Vitamin K?
Vitamin K is the collective name of a family of compounds. “There are different categories within vitamin K,” says Rayanne Nguyen, RD, a specialist 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.
How to Improve Absorption
As a fat-soluble vitamin, vitamin K from food is best absorbed when there’s fat or oil in the same environment. So when you’re having your green vegetables, toss them in some oil to increase your intake. However, some people with underlying health conditions may need more help and possibly a supplement to improve their nutrient absorption. “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.
Precautions
There are 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 Nijya Saffo, RD, owner of NK Fitness and Nutrition, LLC. “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.” Speak with your doctor if you are taking blood thinners before you dramatically alter your diet by either eliminating or adding foods high in vitamin K.
Daily Recommended Value
So how much vitamin K do you need? The unofficial daily value for vitamin K is between 90 and 120 micrograms. For context, one cup of raw spinach contains more than 100% of the daily recommended value, so you don’t need to eat much of the foods listed below to consume a healthy amount of vitamin K. While a consistent intake is important, you don’t want to overdo it. Your body treats vitamin K like 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.
