What Is Vitamin K and Why Do We Need It? Here's What a Dietitian Has to Say

When you think of vitamin C, maybe an orange comes to mind. Or a banana might pop into your head when you think of potassium. But with vitamin K, you might be drawing a blank. This nutrient might fly under the radar, but it is responsible for some crucial bodily functions. Lucky for us, our body utilizes vitamin K whether we are familiar with it or not. However, a little know-how can go a long way when it comes to getting the most out of this helpful nutrient. Here we dive into what vitamin K is, foods high in vitamin K and the health benefits that come with getting plenty of it.

What Is Vitamin K?

Vitamin K is a fat-soluble vitamin that is crucial for bodily function. It comes in two forms: vitamin K1 (phylloquinone) and vitamin K2 (menaquinone). Vitamin K1 is primarily found in plant foods, whereas vitamin K2 is more common in animal foods. Our body can use both forms of the vitamin, and vitamin K2 is even produced by some of the bacteria in our gut.

Vitamin K is a nutrient that our body needs to stay healthy and functioning at its best. The daily recommended intake for vitamin K is 120 micrograms for men and 90 mcg for women. If you're regularly eating fruits and vegetables, you shouldn't have too hard of a time hitting those goals. One cup of raw spinach alone delivers 145 mcg of vitamin K!

However, because vitamin K is a fat-soluble nutrient, it needs to be paired with a fat to be properly absorbed. So plan on including a healthy fat at meals to help you get the most out of what's on your plate.

And to clear up any confusion: Vitamin K and potassium aren't the same thing. "K" is the sign for potassium on the periodic table of elements, so we see how it can get jumbled. However, potassium is completely different and a mineral, not a vitamin. It does have its own set of impressive health benefits, though!

Pictured Recipe: Kale & Avocado Salad with Blueberries & Edamame

Foods High in Vitamin K

There are many plant and animal foods that can help us meet our vitamin K goals. Foods like dark leafy greens and cruciferous vegetables, in particular, pack an impressive amount of the nutrient. Here are some of the most potent food sources of vitamin K:

• ½ cup cooked collards: 530 mcg (442% DV)
• 1 cup raw spinach: 145 mcg (121% DV)
• 1 cup raw kale: 113 mcg (94% DV)
• ½ cup cooked broccoli: 110 mcg (92% DV)
• ½ cup roasted soybeans: 43 mcg (36% DV)
• ½ cup canned pumpkin: 20 mcg (17% DV)
• ¾ cup pomegranate juice: 19 mcg (16% DV)
• ½ cup raw okra: 16 mcg (13% DV)

Health Benefits of Vitamin K

Now that we have covered what vitamin K is and what foods to get it from, here are some perks of making sure you get enough.

Keeps Bones Strong

Our bodies need adequate amounts of vitamin K to produce a specific protein, osteocalcin. Osteocalcin is found in bones and is important for helping bones stay strong over time. In fact, research has found that people who get enough vitamin K have a significantly reduced risk of fractures, especially as they age. This is likely due to the role it plays in improving bone mineral density.

Protects Your Heart

There's growing evidence for the heart-healthy benefits of vitamin K. A recent study in the Journal of the American Heart Association found that people with a diet rich in vitamin K had a 34% lower risk of atherosclerosis than those with the lowest intake. This could be related to vitamin K's involvement in the compound matrix Gla protein (MGP). MGP helps prevent calcification or hardening of the arteries, which can lead to heart disease.

Boosts Brain Health

Vitamin K might also help keep your mind sharp as you age, too. One study found that people over age 70 with the highest intake of vitamin K (especially from plant-based sources) had better verbal memory performance. Not to mention, many high-vitamin-K foods like dark leafy greens are also the cornerstone of a brain-healthy diet.

What about a Vitamin K Supplement?

With all the benefits that come from getting enough vitamin K, you might be thinking, "Should I take a vitamin K supplement?" The reality is you can get what you need from food, so supplementation isn't necessary (unless otherwise instructed by your health care provider).

Warfarin and Vitamin K

There still seems to be a lot of confusion around vitamin K and blood-thinning drugs, like warfarin (also called Jantoven and Coumadin). Here's the deal: Vitamin K is needed for proper blood clotting. Blood clotting is important because it stops bleeding and allows the body to start healing. Without adequate vitamin K, a simple cut can become more dangerous. That being said, vitamin K deficiency is very rare, so you don't really need to worry.

Yes, vitamin K has the potential to counteract the effects of blood-thinning medication, but it doesn't mean it's off-limits. Rather than avoid it completely, what's more important is eating consistent amounts of vitamin K-rich foods each day. Aim to include a serving or two of vitamin K-rich food at most meals and you should be fine. If you're on a blood-thinning medication, your doctor will regularly check that it's working as it should and can adjust your dose accordingly.

Bottom Line

Even though it might not be the most talked about nutrient around, vitamin K is crucial for keeping our bodies healthy and functioning at our best. Whether it's aiding in blood clotting or keeping our bones strong and healthy, there are several reasons to make sure you're getting enough of this important nutrient.