Vitamin K is a group of compounds. The two most common compounds are vitamin K1, also known as phylloquinone, which is found in green leafy vegetables, and vitamin K2, or menaquinone, which is found in meats, eggs and cheeses. Vitamin K is a fat-soluble vitamin that the body stores in the liver and other body tissues, such as the brain, bones, and heart.
Although vitamin K is available in supplement form, nutritionists and health experts recommend increasing your intake of foods rich in vitamin K. Here’s a look at which foods will give you the most vitamin K and how this vitamin benefits the body
What are the benefits of vitamin K?
Vitamin K is better known as the “clotting vitamin” because it plays an essential role in blood clotting, says Anna Taylor, MS, RD, LD, CDCES, a registered dietitian at the Cleveland Clinic Center for Human Nutrition.
“Prothrombin is a plasma protein that helps blood clot,” he explains. “This protein depends on vitamin K to function. Blood will take longer to clot for people who are deficient in vitamin K, leading to bruising and bleeding problems.”
Related: 11 Best Vitamin D Supplements
The vitamin is also essential for bone metabolism. Adequate intake of vitamin K, along with calcium and vitamin D, supports bone health. Taylor says not getting enough vitamin K could lead to osteoporosis.
Vitamin K has also been shown to reduce the risk of severe COVID-19, he says Dr. Linda Anegawa, MDa physician dually board-certified in internal medicine and obesity medicine, and medical director of virtual health platform PlushCare.
11 Foods rich in vitamin K
Vitamin K is fat-soluble, meaning the body absorbs it best when consumed with fat, Taylor says. “For people trying to increase their vitamin K intake, include some healthy fat, such as salmon, nuts, or olive oil (which contain the same vitamin K) in the same meal as your green leafy vegetables”.
The adequate intake of vitamin K is 120 micrograms (mcg) per day for men and 90 mcg for women. Here are 11 vitamin K-rich foods you should add to your diet:
1. Natto
This Japanese dish made with fermented soybeans is an excellent source of vitamin K, says Taylor. Just 3 ounces contain 850 mcg of the vitamin. Research shows that regular natto consumption offers bone health benefits in older men.
Related: 25 Best Vitamin C Foods and Drinks
2. Collards and turnips
Green leafy vegetables contain the highest levels of phylloquinone or vitamin K1. Half a cup of boiled collard greens contains 530 mcg of vitamin K, while half a cup of boiled turnip greens contains 426 mcg. Stir a few handfuls of these vegetables into a soup to boost your nutrient count.
3. Spinach
One cup of raw spinach contains 145 mcg of vitamin K. Spinach also contains a large amount of other nutrients, including potassium, vitamin C and iron. Use this leafy green as a salad base or sauté it as a side for a nutrient boost.
4. Kale
Kale is another leafy green to add to your diet to boost vitamin K levels. One cup of raw kale will give you 113 mcg of the vitamin.
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5. Broccoli
Whether you’re steaming, sautéing, or roasting it, broccoli will add a vitamin K boost to any meal. Half a cup of boiled broccoli contains 110 mcg of vitamin K. Be sure to include the stems and leaves with the florets for an extra dose of phylloquinone.
6. Soy
Soybeans are another great source of vitamin K. They are also rich in protein and fiber, and a good source of omega-3 fatty acids. Half a cup of roasted soybeans contains 43 mcg of vitamin K, and half a cup of frozen edamame has 21 mcg.
Related: Can olive oil be used instead of vegetable oil?
7. Soybean and canola oils
Because vitamin K is a fat-soluble vitamin, sautéing vegetables in soybean or canola oil, which also contains vitamin K, can dramatically increase nutrient intake. Another option is to toss a salad with a dressing made with these oils. A single tablespoon of soybean oil contains 25 mcg, and a tablespoon of canola oil has 10 mcg.
8. Olive oil
Olive oil is a healthy fat that can increase the body’s absorption of vitamin K when combined with other foods rich in the vitamin, such as broccoli or kale. One tablespoon of olive oil contains 8 mcg of vitamin K.
9. Pine nuts
Pine nuts are a rich source of vitamin K. One ounce of pine nuts contains 15 mcg of vitamin K. Other nuts, such as cashews, are also good sources of vitamin K.
10. Lettuce
Romaine lettuce, butter lettuce, and green and red leaf lettuce offer 100 mcg to 126 mcg of vitamin K, depending on the variety. This is equivalent to most of the daily value of the vitamin. So consider adding a salad to most of your meals, especially one with a dressing made from olive or soy oil.
11. Pumpkin
This fall staple is a good source of vitamin K. Half a cup of canned pumpkin contains 20 mcg of the nutrient. So all that pumpkin bread, pumpkin pie, and even your PSL can be good for you.
Can you consume too much vitamin K?
It’s hard to get too much vitamin K, and vitamin K toxicity is rare, Anegawa says. That’s because vitamin K, unlike other fat-soluble vitamins, is broken down quickly by the body, so it’s unlikely to reach toxic levels, Taylor says.
But some people need to watch their vitamin K intake. For example, the vitamin can interfere with the effects of certain blood-thinning drugs, such as warfarin, Taylor says.
Also, says Anegawa, people with some liver and gallbladder diseases may be at risk for vitamin K deficiency. Taking antibiotics can also cause deficiency, as the drugs can affect gut bacteria, which can make it harder the recycling of vitamin K in the body.
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Sources:
- Dr. Linda Anegawa, MD, a board-certified physician in internal medicine and obesity medicine, and medical director of virtual health platform PlushCare
- Anna Taylor, MS, RD, LD, CDCES, registered dietitian at Cleveland Clinic’s Center for Human Nutrition
- Open Forum Infectious Diseases, “Vitamin K and D deficiencies are independently associated with COVID-19 disease severity”
- MedlinePlus, “Vitamin K”
- Mount Sinai, “Vitamin K”
- National Institutes of Health, “Vitamin K”
- Osteoporosis International, “Association between vitamin K intake from fermented soybeans, natto and bone mineral density in older Japanese men: the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study”
- Food and Nutrition Research, “Vitamin K: Food Composition and Dietary Intake”