Vitamin K Foods: Health Benefits, Deficiency and More

A vitamin is an organic molecule and an essential micronutrient. Therefore, we need it in tiny amounts for normal functioning, growth and maintenance of body tissues. Unfortunately, our bodies can not synthesise these crucial micronutrients, either at all or not in sufficient quantities. Since they are either soluble or dissolvable, in fat or water, they divide into water-soluble and fat-soluble vitamins. Therefore, it becomes essential to consume them through a diet. There are several vital vitamins we should consume. Most of us are aware of the vitamins A, B, C, D, and E, but did you know the importance of vitamin K?

When was the last time you were bleeding from scraped knees, paper cuts, or a finger you sliced while chopping? Do you know when the scratch stopped bleeding? Maybe a minute, or perhaps you covered it in a bandage and didn’t realise it was gone for hours? Have you ever pondered how this is possible? Do you know who is in charge of these actions in our bodies? The answer to these questions is vitamin K, a fat-soluble vitamin. It is one of the 13 vitamins in the human body and is essential for blood clotting. In the absence of vitamin K, the body won’t stop bleeding. It is abundantly available in both plant and animal sources. Most people can meet their daily requirements of vitamin K by balanced meals only.

Vitamin K: Everything You Should Know

Vitamin K is an essential vitamin in creating three critical proteins in the body. It protects your arteries from calcium accumulation and primarily involves blood clotting, bone metabolism, and building proteins. It does its work in the liver and other tissues, including the brain, pancreas, and heart, as well as your skeletal system.

While Vitamin K may sound like one compound, it is a group of compounds. Vitamin K1 and Vitamin K2 are the most critical compounds, also known as Phylloquinone and Menaquinone. The production of vitamin K2 (or menaquinone) primarily occurs in intestinal flora or the “gut bacteria”. On the other hand, you can mainly obtain vitamin K1 (or phylloquinone) from the diet, especially green leafy vegetables.

Vitamin K: Required Daily Intake

As per scientific research, the Adequate Intake (AI) of Vitamin K for different people in various age groups is:

Infants

• 0 to 6 months: 2 mcg
• 7 to 12 months: 2.5 mcg

Children

• 1 to 3 years: 30 mcg
• 4 to 8 years: 55 mcg

Women

• 9 to 13 years: 60 mcg
• 14 to 18 years: 75 mcg 
• 19 years and older: 90 mcg
• During pregnancy and lactation: 90 mcg

Men

• 9 to 13 years: 60 mcg
• 14 to 18 years: 75 mcg 
• 19 years and older: 120 mcg

Top 15 Vitamin K Rich Foods to Add to Your Diet

1. Kale

Kale is a superfood that is extremely rich in the dietary form of vitamin K, called phylloquinone. For example, 100 grams of cooked or boiled kale without salt offers 817mcg of vitamin K. It is approximately 681% DV (Daily Value) of vitamin K, making kale the best plant-based source with the highest vitamin K levels. It is best to eat it raw or add it to salads, pasta, or soups.

Kale is available year-round and serves as a nutritional powerhouse. Besides being packed with vitamin K, kale contains fewer calories and very few fats. According to a study, drinking kale juice significantly lowers bad cholesterol levels and reduces the risks of coronary artery diseases.

2. Collard Greens

For a healthy dose of vitamin K and other essential nutrients, collard greens are one of the best options. It is high in vitamin K and provides more than 800mcg per serving. As per the USDA data, 100 grams of raw collard greens has about 437mcg of vitamin K. It provides nearly 370% of recommended daily vitamin K levels.

Collard greens contain vital B-complex vitamins, calcium, iron, folate, and potassium. Its nutritional profile supports bone and blood health in many ways. For example, vitamin K can improve calcium absorption and reduce bone fracture risk. In addition, collard greens can potentially combat the carcinogenic factors that cause kidney, colorectal, and breast cancer.

3. Spinach 

Besides being a rich source of iron, spinach also offers the goodness of vitamin K, C, and A. 100 grams of raw spinach contains 483mcg of vitamin K. It makes up to 402% of daily vitamin K requirements. However, eating cooked spinach provides more vitamin K than raw spinach. For example, vitamin K in one cup of cooked spinach is about 888.5 mcg, while one cup of raw spinach has only 144.9mcg.

Vitamin K in spinach is essential for blood clotting. Eating spinach is suitable for your general health as well. A study shows that the nitrates present in spinach leaves can regulate your blood pressure, promoting cardiovascular health. In addition, it is generally suitable for boosting the haemoglobin ratio and eye health.

4. Broccoli

Broccoli might not be a favourite choice for many, but it has several health benefits. One hundred grams of raw broccoli provides 102mcg of vitamin K, and 100 grams of cooked broccoli has about 141mcg. However, you should ensure not to overcook it to preserve its vitamins and other nutrients.

Adding vitamin K rich broccoli to your diet helps with strengthening your immunity. Plus, it has fibre and vitamin C. Moreover, studies show that consuming broccoli sprouts every day can improve insulin resistance among people with type 2 diabetes.

5. Eggs

Eggs are an easy meal option. The vitamin K range in a single egg yolk is between 67 and 192mcg. So eating one large egg gives you 5% DV or 5.8 mcg of vitamin K. You can either consume raw egg yolks, boil it, or scramble it.

Eggs offer much more than protein and vitamin K. They help improve good cholesterol levels and repairs body tissues. In addition, eggs make you feel full, thereby aiding in weight management.

6. Cheese

Different varieties of cheese have different levels of vitamin K content. So no matter what cheese you prefer, adding them to your diet equals adding vitamin K. Soft cheeses offer 59 mcg or more vitamin K per 100g, while hard cheeses provide about 87mcg or more.

In addition to vitamin K, cheese enriches your diet with protein, fat, and calcium. For underweight people, consuming cheese helps to gain weight healthily. However, make sure to consume it in moderation.

7. Soybeans 

Vitamin K is available in two forms; vitamin K1 and vitamin K2. Soybeans are a good source of both vitamin K1 and K2. For example, 100 grams of steamed or cooked soybeans contain nearly 70.6mcg of vitamin K. You can also get 43mcg of vitamin L from consuming a standard half-cup serving of roasted soybeans.

The primary health benefits of soybeans include their role in diabetes management, inducing quality sleep, and improving blood circulation. It is also suitable for pregnancy due to folic acid and vitamin B complexes.

8. Chicken

Chicken is the best vitamin K source for non-vegetarians. Adding 100 grams of chicken to your diet ensures the supply of 60 mcg of vitamin K, equal to 50% DV. Chicken liver is also vitamin K rich and offers up to 13mcg per 100 grams serving. Grilled and pan-seared chicken are better cooking choices for retaining its benefits.

Chicken is rich in nutrients, including proteins, selenium, and niacin. For those on a weight loss journey, eating the recommended amount of chicken enhances feelings of fullness. Furthermore, it helps build muscles, keeps bones healthy, and boosts testosterone levels in men.

9. Bacon

Bacon also comes under the list of vitamin K rich foods. One hundred grams of bacon contains 35 mcg or 29% DV of vitamin K. Pan-fried, roasted, or broiled bacon are some options to try.

Bacon shows a high protein to fat ratio, thereby serving as a good source of animal protein. In addition, its micronutrients support muscle strength, heart functions, and bone health.

10. Lettuce

In American diets, lettuce is a popular source of vitamin K. 100 grams of raw, green leaf lettuce provides you with 126mcg of vitamin K. You’ll get nearly 60mcg of vitamin K per serving. In addition, 95% of raw lettuce is composed of water. Thus, it is suitable for hydration. Furthermore, lettuce extract improves sleep and vision.

11. Green Peas

Legumes like green peas provide 26mcg of vitamin K, about 22% DV. Eating half a cup of cooked green peas ensures the intake of 21mcg or 17% DV. You can eat it as a side dish or add them into soups and stews. In addition, green peas also help boost immunity due to their antioxidant properties and reasonable vitamin C, vitamin K and zinc content. Green peas also have anti-inflammatory properties and are beneficial for the heart.

12. Prunes

Most fruits lack vitamin K, but prunes have a decent amount of it. Prunes provide 60mcg or 50% DV of vitamin K per 100 grams serving. Each prune is worth 5.7 micrograms of vitamin K. If you’re consuming half a cup or about nine prunes, it equals 51.8mcg of vitamin K. You can simply add chopped pieces of prunes into salads or blend them in smoothies.

Prunes can limit bone loss, thereby improving bone density in postmenopausal women. In addition, it is suitable for digestion and heart health. However, avoid consuming large amounts as they might cause a laxative effect.

13. Kiwi

Kiwi is another fruit with a healthy amount of vitamin K. It provides 40.3mcg of vitamin K per 100 grams of serving, making up to 34% DV. You can eat it as it is or incorporate it into salads, juices, and custards.

Speaking of its health benefits, kiwis are good for bone health and warding off cardiovascular disease. In addition to vitamin K, kiwi also offers vitamin C and fibre. Moreover, they are suitable for cellular repair and digestion, respectively.

14. Cashews

Cashews contain a sufficient dose of vitamin K. 100 grams of raw cashews provides 34.1mcg of vitamin K, 28% DV. Therefore, eating one ounce or 28.35 grams of cashews will ensure 11% of vitamin K daily value for women and 8% for men.

Cashews are full of heart-healthy fats, and at the same time, they’re low in sugar. As a result, it is a popular plant protein involved in immunity, brain health, and energy production.

15. Pine Nuts 

Eating 100 grams of pine nuts supplies you with 54mcg of vitamin K, 45% DV. One standard cup of dried pine nuts can give 81% of vitamin K DV for women and 61% for men. The energy-boosting power of pine nuts makes it a good snack choice. Additionally, it is a superfood that protects the heart and gives a buttery flavour to your diet.

Vitamin K Deficiency

Vitamin K deficiency is rare as it is widely available from the diet, and you also get it from gut bacteria. Still, it can happen when using antibiotics, which inhibit vitamin K metabolism. It also occurs in those who have a condition that causes malabsorption of food and nutrients. Furthermore, it is a risk to people suffering from gastrointestinal disorders.

Vitamin K deficiency is also common in newborns because it does not pass the placenta. Incidentally, breast milk contains only a minimal amount. Therefore, if you do not give newborns vitamin K supplements, their blood clotting proteins deplete, increasing their risk of bleeding.

The most common symptoms of Vitamin K deficiency are:

• Prolonged prothrombin time or a longer time for blood to clot
• Osteopenia or osteoporosis
• Haemorrhaging
• Bleeding

Vitamin K: Health Benefits 

Both vitamin K1 and vitamin K2 are essential for overall health. The following are some of the most well-known health benefits of both forms of vitamin K.

Vitamin K improves Bone Health

Studies show that Vitamin K and Vitamin D work together to help the body metabolise calcium, necessary for healthy bones. Vitamin D is helpful for calcium absorption in the small intestine, and vitamin K aids in the accumulation of calcium in the bones, which keeps them strong.

Vitamin K is also involved in producing proteins in bone, including “osteocalcin”, which helps prevent the weakening of bones.

Heart Health

The accumulation of calcium in the arteries surrounding your heart is a significant cause of heart disease. As a result, anything that can help reduce calcium build-up is beneficial in preventing heart diseases. Vitamin K helps this by promoting regular calcium metabolism and preventing dangerous calcium plaque build-up (arterial calcification) in the arteries, improving heart health.

Blood Clotting

Vitamin K promotes the production of the protein prothrombin and osteocalcin required for blood clotting, allowing wounds to heal and healthy bone tissue to form. As a result, it also helps mitigate the effects of blood-thinning medications.

Vitamin K Maintains Blood Pressure

When combined with vitamin D, vitamin K helps lower blood pressure by inhibiting mineralisation or the accumulation of minerals in the arteries. As a result, the heart can pump blood efficiently throughout the body. 

Best Ways to Consume Vitamin K

Vitamin K2 and Vitamin D

Vitamin D is another fat-soluble vitamin that works closely with vitamin K to perform various bodily functions. These include regulating calcium metabolism for bone and heart health. Research indicates that Vitamin K2 boosts vitamin D absorption.

Once vitamin D transports calcium into your blood, K2 activates the protein osteocalcin. It ensures that the protein works for your bones instead of ending up in your arteries and causing potential heart health issues. So, it is best to take vitamin D supplements with vitamin K2.

Vitamin K and Fats 

The absorption of vitamin K from food sources is about 20%. However, when combined with dietary fats, its absorption can increase. So, drizzle some hazelnut oil or olive oil into your favourite leafy green salads and curries.

Use Soybean Oil

While cooking, try to use soybean oil to boost the supply of vitamin K. It has much higher vitamin K than other oils. Therefore, it is the best way to add vitamin K to your daily diet. For instance, one tablespoon of soybean oil has about 25mcg of vitamin K.

Go For Combos

Food is the best way to multiply your vitamin K intake. Instead of trying one vitamin K rich food, pair it with other options. For example, adding prunes, cashews, and kale to your salad provides more benefits than eating them separately. Craving noodles? Try spinach noodles with chicken. It all depends on how you pair the foods.

Vitamin K: Possible Side Effects and Precautions

Unlike other fat-soluble vitamins, vitamin K is easily broken down and eliminated through urine or faeces. Because of this, even at large doses, it rarely reaches dangerous levels in the body; therefore, its toxicity is not common.

However, its toxicity relates to its water-soluble nature. When toxicity does occur in infants, it manifests with signs of jaundice and hemolytic anaemia. Furthermore, other symptoms include hyperbilirubinemia and kernicterus.

Drug Interaction

Medications aren’t always appropriate for everyone. As a result, people undergoing specific medical treatments should avoid using vitamin K supplements. People taking the following medicines should also consult a doctor before taking these supplements.

• Antacids
• Antibiotics
• Blood thinners
• Aspirin
• Drugs for cancer
• Seizures stabilizing Drugs
• Drugs for high cholesterol

Goitre Risk From Food Sources

You can abundantly get vitamin K through leafy veggies like collard greens. Being a member of the Brassica family, collard greens contain goitrogens. They are a type of compound that can trigger the risk of getting goitre. It may cause abnormal swelling of the thyroid gland. Hence, people with thyroid dysfunction must avoid consuming raw collard greens for vitamin K.  However, steaming and boiling can lower their goitrogen content.

Conclusion

Vitamin K is a fat-soluble vitamin that the body needs for proper blood clotting, strong bones, and cardiovascular health. Therefore, you need to consume adequate vitamin K to function correctly. It is abundant in most food products, and a balanced diet can help prevent its deficiency. 

Dark leafy green vegetables are the best source of vitamin K1 or phylloquinone. You can also consume vitamin K sources and healthy fats for optimum absorption. However, certain circumstances, such as chronic sickness and certain drugs, can interfere with your levels and lead to health issues.

Frequently Asked Questions (FAQs)

Q. Does coffee have vitamin K?

A. No, coffee does not have vitamin K. However, a 100 g cup of coffee has 355 calories with 0 g total fat and cholesterol. It also has 277 mg sodium and 79 g carbohydrate, which are beneficial for your health.

Q. What are the symptoms of low vitamin K?

A. Vitamin K deficiency is rare but can happen in people using antibiotics or with the condition of malabsorption of nutrients. One of the most common vitamin K deficiency symptoms is bleeding or haemorrhage into the skin, which produces bruises. These might occur in the nose, from a cut, in the stomach, or in the intestine. Urine or faeces may also include blood, or stools may become tarry black.

Q. Who is most at risk for vitamin K deficiency?

A. Vitamin K does not pass the placenta. Breast milk also contains only a minimal amount. Hence, all infants are at higher risk of bleeding from VKDB or Vitamin K deficiency until they start eating regular foods. It usually occurs at age 6-7 months until the normal intestinal bacteria make vitamin K.

Q. What vitamin deficiency causes clots?

A. Vitamin K helps in the production of several proteins. These proteins are helpful for blood clotting and bone formation. For example, prothrombin is a vitamin K-dependent protein that plays a direct role in blood clotting.

Q. Which disease is caused due to lack of vitamin K?

A. Vitamin K deficiency bleeding (VKDB) is a problem that occurs in people with low levels of Vitamin K. Unfortunately, its deficiency can also lead to poor bone development and osteoporosis. Furthermore, it increases the risk of cardiovascular disease.

Q. How can I increase vitamin K absorption?

A. Bioavailability of Vitamin K through diet is only about 20%. However, it is a fat-soluble vitamin. Thus, combining it with dietary fats can help increase its absorption.

Q. Does vitamin K thicken or thin the blood?

A. Vitamin K helps thicken the blood to form a clot and stop bleeding. Furthermore, warfarin is a pill that reverses the action of vitamin K. Thus; they work against each other according to your situation.

Q. Do you need vitamin K with vitamin D?

A. Vitamin D is a fat-soluble vitamin and helps transport calcium to blood. Vitamin K works closely with Vitamin D to regulate calcium metabolism and activates osteocalcin. This protein ensures that the calcium reaches your bones instead of ending up in your arteries and causing plaque build-up or arterial calcification in the arteries.