In a fast-paced life, we often neglect the importance of a wholesome meal. Vitamins are paid the least attention. Vitamin K deficiency affects 50% of infants in the US, among other vitamin deficiencies. Including vitamin K-rich foods in daily diet can greatly help to combat this.
Although rare, this deficiency may cause excessive bleeding and hemorrhage even in adults.
If this deficiency is not corrected in infants, it may be fatal at times.
Hence, knowing which foods have this vitamin in abundance is necessary. This article will help you understand the importance of vitamin K and its science-backed benefits. You will also learn about the best dietary sources of vitamin K, recommended dosage, and other benefits of the vitamin. Scroll down to read further.
In This Article
- Why Vitamin K – The Science
- What Are The Foods Rich In Vitamin K2?
- What Are The Foods Rich In Vitamin K1?
- What Are The Benefits Of Vitamin K?
- What Is The Recommended Daily Allowance Of Vitamin K2?
Why Vitamin K – The Science
Your body needs vitamin K to produce a protein called prothrombin, which helps in blood clotting and bone metabolism. This vitamin can protect you from osteoporosis, boost your heart health, and help prevent cancer.
Probably, the most important aspect of vitamin K is how it can help treat vitamin K deficiency bleeding in infants. All infants are a higher risk of this condition until they are 4 to 6 months old, which is when they usually start eating regular foods, and the intestinal bacteria start synthesizing vitamin K as well. This is where vitamin K shots help – one shot given to the baby’s thigh can prevent the condition. Negligence in this aspect can be fatal (1).
There are three types of vitamin K, but only one of them is the most beneficial:
- Vitamin K1 (also called phylloquinone) is what you find naturally in green veggies. It enters your liver and aids blood clotting.
- Vitamin K2 (also called menaquinone) is found in animal and fermented products and is also produced by your gut bacteria. It goes to your bones and blood vessels and other tissues other than your liver.
- Vitamin K3 (also called menadione) is a synthetic form of the vitamin that is not recommended.
The most potent and effective form of vitamin K is K2. It is natural and not toxic even at 500 times the RDA. Vitamin K2 is made in our body and is also produced in fermented foods. In fact, increasing your vitamin K2 intake is the most recommended and safest way of fighting the deficiency.
There are different ways you can get all the vitamin K2 you need. Most foods contain vitamin K1, and we humans have the ability to partly convert this into vitamin K2. Vitamin K2, as we saw, is also produced by the gut bacteria. But unfortunately, both these methods are not as efficient if you are looking to get abundant levels of vitamin K2.
So, what’s the next best option? Consuming foods rich in vitamin K2.
What Are The Foods Rich In Vitamin K2?
Since vitamin K2 is the best type of the vitamin, we’ll first discuss its food sources. Consuming foods rich in vitamin K can only add to the goodness, and we will check out those too – a little later.
3.5 ounces (100 grams) of natto contains 1,000 mcg of vitamin K2, which is close to 10 times the RDA. You can ideally take 1 ounce of natto for the benefits.
This Japanese staple is made of fermented soybeans. It has a strong flavor and aroma, and most Westerners wouldn’t even have heard of it.
Studies show that intake of natto can increase vitamin K2 levels in individuals (2). Natto is also a good source of protein and fiber, which have their own benefits. While protein helps build the body, fiber aids digestion and promotes healthy weight loss.
How To Include In Your Diet
You can simply top your rice dishes with natto. This is one popular way of consuming it.
100 grams of miso contains 29.3 mcg of vitamin K2, which meets 37% of the RDA.
This is another popular Japanese dish that is made of fermented beans. Fermented foods like miso enhance the beneficial bacteria in the gut, thereby boosting absorption and the assimilation of nutrients. And these beneficial bacteria also synthesize vitamin K2, further enhancing the nutrient levels in the body.
How To Include In Your Diet
You can thicken your salads using miso – it works as a great salad dressing.
1 cup of whole-egg mayonnaise contains 197 mcg of vitamin K2, which meets 220% of the RDA.
This is the cholesterol-free variety, which also contains vitamin E that is good for the heart and skin. Vitamin E is also an antioxidant that protects the body from free radicals.
How To Include In Your Diet
Use mayonnaise as a bread spread for your morning breakfast.
100 grams of lamb chops contain 5.3 mcg of vitamin K2, which meets 7% of the RDA.
Given that lamb is meat, it is rich in protein. It is a high-quality protein source as it contains all the essential amino acids. In addition to vitamin K2, lamb meat also contains good amounts of selenium and zinc, both of which take care of various bodily functions.
How To Include In Your Diet
You can include lamb meat chops in your dinner or lunch.
5. Beef Liver
100 grams of beef liver contains 3.1 mcg of vitamin K2, which meets 4% of the RDA.
Apart from vitamin K, beef liver is an abundant source of iron. In fact, it is one of the best sources of the nutrient. Iron helps generate energy and aids the transportation of oxygen throughout your body.
Beef liver is also replete with vitamin A. Vitamin A promotes vision and skin health.
But be cautious about vitamin A. Since beef liver is rich in it, eating it every day can lead to vitamin A toxicity.
How To Include In Your Diet
You can have beef chops along with your rice preparations.
These are the foods rich in vitamin K2, which, as we discussed, is the most potent form of vitamin K. However, consuming foods rich in vitamin K1 alone can also help – which is what we will cover now.
What Are The Foods Rich In Vitamin K1?
Most green leafy vegetables are excellent sources of vitamin K1. We have covered most of them and a few others, which, if consumed, can improve your vitamin K1 levels like no other. Your body converts some of this vitamin K1 into K2, helping you with adequate levels of the nutrient.
1. Raw Swiss Chard
100 grams of Swiss chard contain 830 mcg of vitamin K1, which meets 692% of the RDA.
2. Cooked Kale
100 grams of kale contain 817 mcg of vitamin K1, which meets 681% of the RDA.
3. Raw Spinach
100 grams of spinach contain 483 mcg of vitamin K1, which meets 402% of the RDA.
4. Collard Greens
100 grams of collard greens contain 407 mcg of vitamin K1, which meets 339% of the RDA.
5. Cooked Cabbage
100 grams of cabbage contain 109 mcg of vitamin K1, which meets 91% of the RDA.
6. Hard Cheese
100 grams of hard cheese contain 87 mcg of vitamin K1, which meets 72% of the RDA.
100 grams of prunes contain 60 mcg of vitamin K, which meets 50% of the RDA.
8. Cooked Green Beans
100 grams of green beans contain 48 mcg of vitamin K1, which meets 40% of the RDA.
9. Sun-Dried Tomatoes
100 grams of tomatoes contain 43 mcg of vitamin K1, which meets 36% of the RDA.
100 grams of kiwis contain 40 mcg of vitamin K1, which meets 34% of the RDA.
11. Blue Cheese
100 grams of blue cheese contain 36 mcg of vitamin K1, which meets 30% of the RDA.
100 grams of bacon contain 35 mcg of vitamin K1, which meets 29% of the RDA.
100 grams of cashews contain 34 mcg of vitamin K1, which meets 28% of the RDA.
14. Cooked Green Peas
100 grams of green peas contain 26 mcg of vitamin K1, which meets 22% of the RDA.
100 grams of kale contain 21 mcg of vitamin K1, which meets 18% of the RDA.
100 grams of avocados contain 21 mcg of vitamin K1, which meets 18% of the RDA.
100 grams of kiwis contain 19 mcg of vitamin K, which meets 16% of the RDA.
100 grams of pomegranate contain 16 mcg of vitamin K1, which meets 14% of the RDA.
These are the other everyday foods rich in vitamin K1. But why should you even know about them? How can they serve you?
What Are The Benefits Of Vitamin K?
Intake of adequate vitamin K (vitamin K1 or K2) can benefit you in more ways than one.
1. Vitamin K2 Improves Bone Density
Did you know that your body needs vitamin K2 to use calcium and build bones?
Most often, we focus on calcium alone, but vitamin K2 is as important for strong bones as any other nutrient.
Vitamin K2 improves bone quality, and this can reduce the risk of fractures. Which is why the vitamin may also help treat postmenopausal osteoporosis (3).
2. Prevents Bleeding In Infants
We already saw this. Since infants can’t eat regular foods until they are 4 to 6 months old, they are at a higher risk of vitamin K deficiency – which can often lead to fatal bleeding. More so, infants’ intestinal flora are not developed to synthesize vitamin K1 yet.
Studies show that this can be prevented by an oral dose of vitamin K1 after birth (4).
3. Is Good For The Heart
One major reason for heart attacks is the calcification of arteries – when calcium from the blood gets deposited within arteries, forming plaques. Vitamin K2 prevents this. It keeps calcium out of your artery linings, thereby boosting heart health (5).
4. Can Help Fight Cancer
The anti-inflammatory effects of vitamin K2 can prevent cancer. Studies show how this nutrient can have tumor-suppressive actions (6). Other studies show how long-term intake of vitamin K2 can prevent death from cancer.
5. Vitamin K1 Enhances Brain Function
The anti-inflammatory properties of vitamin K1 can prevent oxidative stress in the brain, and this improves cognitive function as a result. Vitamin K1 also boosts the functioning of sphingolipids, compounds that support the optimal performance of the brain.
6. Helps With Blood Clotting
Vitamin K1 is used by the body to help blood clot, and this can be beneficial during injury.
As we discussed, vitamin K2 is the most potent and highly recommended form of the nutrient. How much of vitamin K2 must you take for these benefits? Any specific dosage?
What Is The Recommended Daily Allowance Of Vitamin K2?
The following table will give you an idea:
|Upto 6 months||2 mcg||2 mcg|
|7 to 12 months||2.5 mcg||2.5 mcg|
|1 to 3 years||30 mcg||30 mcg|
|4 to 8 years||55 mcg||55 mcg|
|9 to 13 years||60 mcg||60 mcg|
|14 to 18 years||75 mcg||75 mcg|
|19+ years||120 mcg||90 mcg|
|19+ years (pregnancy and/or lactation)||90 mcg|
Not meeting these dosages can lead to a deficiency of vitamin K1 or K2, the symptoms of which include:
- You might bruise easily.
- You might experience blood clots underneath your nails.
- You may get dark black stools (with blood, sometimes).
However, consuming vitamin K (K1 or K2) in excess or under certain conditions can have detrimental effects too. These can include the following:
- Issues During Pregnancy And Breastfeeding
Vitamin K is safe in recommended amounts. If you are pregnant or breastfeeding, avoid consuming it in high amounts.
- Might Lower Blood Sugar Way Too Much
Vitamin K may lower blood sugar levels, and this may cause issues if someone is already on blood sugar medication.
- May Harm The Kidneys
Excess vitamin K can interfere with dialysis – if you are receiving the treatment for kidney disease.
- May Aggravate Liver Disease
High doses of vitamin K can make clotting issues worse in people with liver disease
Our bodies do synthesize vitamin K2, but it is not enough to meet the daily recommended levels. So, the best way out is to consume vitamin K-rich foods, which largely include natto, miso, mayonnaise, lamb, beef, liver, etc. Infants are generally deficient in vitamin K as they do not consume regular foods, so a shot of this micronutrient is essential to prevent vitamin K1-deficiency-bleeding. Besides, it enhances bone and brain health and reduces the risk of cancer, heart disease, and osteoporosis.
Men and women above the age of 19 must try to take 120 mcg and 90 mcg of vitamin K2, respectively, to meet the body’s requirements.
Frequently Asked Questions
What happens if you take too much vitamin K?
If it is the vitamin K you get from food or intestinal synthesis, toxicity is rare. But when your dose exceeds through supplements or injections, the vitamin can build up in your blood and become toxic. Symptoms include sweating, tightness in your chest, and even flushing.
Is vitamin K water-soluble?
No, it is fat-soluble. Vitamin K is soluble in lipids (fats); it is absorbed in fat globules that then travel through the intestines and into the blood circulation of the body.
Is vitamin K the same as potassium?
No. Both are different and essential micronutrients.
- “Facts about vitamin K deficiency bleeding”. Centers for Disease Control and Prevention.
- “Intake of fermented soybean (natto)…”. US National Library of Medicine.
- “Osteocalcin: the vitamin K-dependent…”. US National Library of Medicine.
- “Vitamin K deficiency bleeding in infants…”. US National Library of Medicine.
- “Proper calcium use: Vitamin K2 as a promoter of…”. US National Library of Medicine.
- “Vitamin K and cancer”. US National Library of Medicine.