6 Key Differences Between Vitamin K and Potassium

Vitamin K: Not the same as potassium. But you’re not alone if you thought they were.

“People may think that vitamin K and potassium are the same nutrient because the letter K is the symbol for potassium on the periodic table of elements,” says registered dietitian Natalie Crtalic, RD, LD. “And of course, vitamin K has the letter K in it.”

Fun fact: The K for potassium may come from the word kalium, which is Medieval Latin for potash or potassium.

But vitamin K and potassium come from different foods and provide distinct health benefits. Plus, you only need a little vitamin K and just the right amount of potassium (not too much!) to stay healthy.

To help clear up any confusion, Crtalic shares key differences — and some similarities — between vitamin K and potassium.

Vitamin K vs. potassium

Vitamin K and potassium are both micronutrients. They help keep your heart, blood pressure, muscles and body systems healthy.

“Your body doesn’t make vitamin K or potassium. You have to get both nutrients from foods,” says Crtalic.

But that’s basically where the similarities end.

1. Potassium is a mineral; vitamin K isn’t

Minerals like potassium come from inorganic (nonliving) sources. Vitamin K and other vitamins come from organic (living) sources.

• Minerals: Potassium is a mineral found in soil and water. You get potassium when you eat plants that absorb this mineral. Similarly, you get some when you eat meat from animals that feed on potassium-rich plants.
• Vitamins: Plants and animals make vitamins. You get vitamin K when you eat certain plants or animals that make the nutrient.

2. Vitamin K and potassium support different body functions

Your body needs vitamin K and potassium to perform a range of activities.

What does vitamin K do?

Vitamin K is mostly known for its blood-clotting abilities. It helps promote wound healing and minimizes bruising. And vitamin K is also essential for:

• Fighting inflammation.
• Healthy heart function.
• Strong bones.

What does potassium do?

Potassium acts as an electrolyte. It carries a positive electric charge throughout your bloodstream to support body functions, such as:

• Balancing fluid levels in cells.
• Contracting muscles to aid movement.
• Keeping your heartbeat in rhythm.
• Lowering blood pressure.
• Sending nerve signals to your brain.

3. Food sources for vitamin K and potassium aren’t always the same

Certain foods like avocados, kale and spinach have both vitamin K and potassium. But generally, you get these nutrients from different foods.

• Vitamin K sources: There are two types of vitamin K: vitamin K1 and vitamin K2. Vitamin K1 is mostly found in cruciferous vegetables and leafy greens. Foods high in vitamin K2 include fermented foods and chicken breast.
• Potassium sources: Potassium-rich foods include bananas, dairy milk, fish, lentils, oranges, potatoes and tomatoes.

4. Your body needs fat to break down vitamin K

Vitamin K is a fat-soluble vitamin, which means it breaks down in fat in your bloodstream. Your body absorbs foods high in vitamin K when you pair them with some healthy fat. For instance, have a spinach-walnut salad with a dressing made with extra virgin olive oil.

5. Your body needs different amounts of vitamin K and potassium

The measurements for vitamin K and potassium differ. Vitamin K is measured in micrograms (mcg). Potassium is measured in milligrams (mg). It takes 1,000 micrograms to make 1 milligram.

The recommended dietary allowance (RDA) for each nutrient is also different. How much you need depends on your age, assigned sex at birth and whether you’re pregnant or breastfeeding (chestfeeding).

RDA for vitamin K

Source: National Institutes of Health

RDA for potassium

Source: National Institutes of Health

6. You can get too much (or not enough) potassium but not vitamin K

Overdoing it (or underdoing it) on vitamin K is rare. But the same can’t be said for potassium.

High potassium levels vs. high vitamin K levels

It’s possible — and even dangerous — to have too much potassium in your blood. High potassium levels (hyperkalemia) can cause muscle weakness and heart rhythm problems like atrial fibrillation.

“People with kidney problems are most at risk because their kidneys have a harder time filtering out the mineral,” notes Crtalic.

But it’s almost impossible to get too much vitamin K from foods (and few people take vitamin K supplements, she says). However, the vitamin’s blood-clotting effects can interfere with blood-thinning medications.

“If you take blood thinners, talk to your healthcare provider. They’ll likely recommend regular blood tests to check vitamin K levels,” says Crtalic.

Low potassium levels vs. vitamin K deficiency

Low potassium levels (hypokalemia) can cause heart palpitations, low blood pressure and muscle cramps and weakness. Potassium levels may drop too low after prolonged bouts of vomiting or diarrhea. People with inflammatory bowel disease (IBD), disordered eating and alcohol use disorder are particularly at risk.

But a vitamin K deficiency is almost unheard of in the U.S.

“Most of us easily get the recommended amount of vitamin K each day with our meals,” shares Crtalic.

Plus, your liver and fatty tissue store fat-soluble vitamins like vitamin K for later use. This differs from water-soluble vitamins, which quickly leave your body when you pee.

Now you know: Vitamin K is not the same as potassium

While vitamin K and potassium share some similarities, they each play different roles in keeping you healthy.

“It’s important to get enough vitamin K and potassium every day — preferably from foods, not supplements,” reinforces Crtalic.