In most cases, the Mediterranean diet provides adequate vitamin K for maintaining good health, and supplements are generally only necessary when there’s a deficiency or specific medical conditions affecting absorption.
The richest foods in vitamin K are dark leafy greens, fermented foods, chicken, and certain cheeses. As there aren’t too many common foods high in vitamin K2, many people may benefit from taking a vitamin K2 supplement.
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Do I Get Enough from the Mediterranean Diet?
Yes, you can get vitamin K by following the Mediterranean diet, as many foods that are central to this eating pattern are rich in vitamin K.
Key Sources of Vitamin K in the Mediterranean Diet:
- Leafy Greens (Vitamin K1): Spinach, kale, arugula, Swiss chard, and parsley are all high in vitamin K1. These are common ingredients in Mediterranean dishes like salads and sautés.
- Olive Oil: Olive oil, a staple of the Mediterranean diet, contains small amounts of vitamin K, contributing to your overall intake. It help its absorption.
- Herbs and Vegetables: Herbs like basil and oregano, as well as vegetables such as broccoli, Brussels sprouts, and cabbage are good sources.
- Fermented Foods (Vitamin K2): Though less emphasized in traditional Mediterranean dishes, some fermented foods like cheese and yogurt can provide vitamin K2.
- Fish and Eggs (Vitamin K2): Small amounts of vitamin K2 are found in fish, eggs, and some animal products, which are also part of the Mediterranean diet.
When You Might Need Vitamin K Supplements:
If you don’t consume enough leafy greens or other vitamin K-rich foods regularly, you may need to consider supplementation.
Also, some people have medical conditions that impair the absorption of fat-soluble vitamins, including vitamin K. Conditions like Crohn’s disease, celiac disease, or liver disease can hinder vitamin K absorption. Long-term use of antibiotics, cholesterol-lowering medications, or anticoagulants can interfere with vitamin K metabolism, increasing the need for supplements.
Vitamin K is important for bone health, and some people at risk of osteoporosis may require supplements if dietary intake is insufficient.
Since vitamin K2 is mainly found in animal products and fermented foods, individuals following a strict vegan diet might need a supplement if their intake of vitamin K2 is low.
It’s important to consult with a healthcare professional before starting any supplements, especially if you’re on blood thinners like warfarin, as vitamin K can interact with these medications.
How much vitamin K do we need a day?
The recommended daily intake of vitamin K is 90 mcg for women and 120 mcg for men.
Actually, there are two types of vitamin K: vitamin K1 and K2. Vitamin K1 is mainly found in plant-based foods (dark leafy greens, in particular), while vitamin K2 is naturally present in animal-based foods.
The human body can synthesize some vitamin K2. Good bacteria in the gut can convert the abundant vitamin K1 into vitamin K2.
If you’re following a healthy, well-balanced diet, you shouldn’t worry about your daily vitamin K intake.
Foods rich in vitamin K1
The best dietary sources of vitamin K are green leafy vegetables.
Foods rich in vitamin K are collards greens, spinach, parsley, coriander leaf, lambs quarters (known as wild spinach), turnip greens, oregano, basil, marjoram, mustard greens, beet greens, Swiss chard, dandelion, cress, kale, stinging nettles, Brussels sprouts, broccoli, onions, and cabbage.
| Vitamin K1 (mcg per 100g) | |
|---|---|
| Basil, dried | 1,714 |
| Sage, dried | 1,714 |
| Thyme, dried | 1,714 |
| Parsley, dried | 1,640 |
| Coriander leaf, dried | 1,359 |
| Parsley, dried | 1,359 |
| Amaranth leaves, dried | 1,140 |
| Swiss chard | 830 |
| Dandelion greens | 778 |
| Collard greens | 623 |
| Marjoram, dried | 622 |
| Oregano, dried | 622 |
| Mustard greens | 593 |
| Dandelion greens | 551 |
| Cress | 542 |
| Spinach | 541 |
| Turnip greens | 519 |
| Stinging Nettles | 499 |
| Lambsquarters | 494 |
Other common plant-based foods containing decent amounts of vitamin K are sweet potato leaves, chicory greens, lettuce, cabbage, Brussels sprouts, arugula, carrots, green beans, pine nuts, seaweeds like kelp, and blueberries.
Additionally, many spices, such as black pepper, red pepper, chili powder, curry powder, paprika, and cayenne are good dietary sources of vitamin K.
Getting high doses of vitamin K either from food or dietary supplements is considered pretty safe. Only people who take certain drugs, such as blood thinners, should be very cautious with consumed vitamin K doses.
Always consult your physician before changing your diet or taking dietary supplements.
Foods rich in Vitamin K2
Vitamin K2 is found mainly in animal-based or fermented foods.
The richest food in vitamin K2 is called natto, which is a traditional Japanese food. It’s actually fermented soybeans. It contains almost 110 mcg of vitamin K2 per 100g! Another plant-based food rich in vitamin K2 is Sauerkraut. It provides 5.5 mcg of vitamin K2 per 100g.[1]
Chicken is the richest common food in vitamin K2 in the Mediterranean Diet. It contains about 10 mcg of vitamin K2 per 100g. Other meat products contain much lower doses of vitamin K.
Sources of Vitamin K2 in the Mediterranean Diet
While vitamin K2 is primarily found in animal-based and fermented foods, which are not consumed in large quantities in the traditional Mediterranean diet, people can still obtain sufficient K2 through various means. Although the diet emphasizes plant-based foods, moderate consumption of animal products and some specific practices help provide adequate amounts of vitamin K2.
Cheese and Yogurt: While the Mediterranean diet limits animal-based foods, it does include moderate amounts of dairy, especially fermented products like cheese and yogurt. Only certain types of fermented cheese are particularly rich in vitamin K2. For instance, Pecorino, Münster, Camembert, Emmental, Stilton, Norvegia, and Gamalost contain 40-94 mcg of vitamin K2 per 100g!
Egg Yolks: Eggs, another animal-based product, are eaten regularly in Mediterranean countries, though not in excessive quantities. The yolks contain small amounts of vitamin K2.[2]
Fatty Fish: Fish like sardines, salmon, and mackerel, which are consumed fairly regularly in the Mediterranean diet, contain modest amounts of vitamin K2. Only eel is particularly high in vitamin K2. It contains 63 mcg of vitamin K2 per 100g.
Meat (in moderation): Although red meat is consumed in smaller amounts, poultry, particularly dark meat (like thighs), can provide some vitamin K2.
Olive Oil and Herbs: Olive oil and certain Mediterranean herbs (like thyme) contain trace amounts of vitamin K1, which your body can convert to K2 in limited quantities.
How do People Get Enough K2 Despite Low Animal Food Intake?
Although not highly efficient, the body has the ability to convert some vitamin K1 (from leafy greens) into K2. This process happens in the gut, but it’s not enough to fully meet K2 needs if dietary intake is low.
Even though animal products are consumed sparingly, they are still part of the diet. The occasional inclusion of eggs, dairy, and fish provides K2 over time. Vitamin K2 is fat-soluble, meaning it can be stored in the body for longer periods compared to water-soluble vitamins. Regular, though modest, intake from these sources can meet long-term needs.
Other Mediterranean lifestyle habits, such as regular physical activity and a diet rich in anti-inflammatory foods, contribute to overall health, particularly bone and heart health, which reduces the dependency on high K2 intake.
What foods should I eat to boost the daily vitamin K intake?
Cheese and other dairy products are high in saturated fatty acids, which can be dangerous for the heart. In fact, the American Heart Association recommends consuming no more than 13 g of saturated fats a day. Higher doses significantly increase the risk of heart disease and stroke.[3]
So, you better consume a wide variety of vegetables in order to get high doses of vitamin K1.
Furthermore, gut bacteria will convert excess vitamin K1 into vitamin K2. Thus, it’s crucial to follow a fiber-rich diet that keeps balanced microbiota. Also, you could drink kefir, which is the richest common food in probiotics! As a bonus, it supports weight loss and boosts immunity.
Can I get enough Vitamin K2 from diet?
It is possible to get enough vitamin K2 from your diet, but it depends on your dietary choices. If you regularly consume foods like natto, nattokinase, aged cheeses, or fermented vegetables, you might be getting sufficient amounts.
Also, you should look for foods like grass-fed beef, chicken liver (smaller amounts than beef liver), or egg yolks, which contain some vitamin K2 (significantly less though).
However, for many people, especially those with limited dietary variety or following restrictive diets, reaching recommended daily intake through food alone can be challenging.
Do I need Vitamin K2 Supplements?
Whether you need vitamin K2 supplements depends on your individual needs and health condition. Consulting a doctor or registered dietitian is recommended to determine if supplementation is necessary for you.
Individuals with osteoporosis, at risk of fractures, might need additional K2 support through supplements under medical guidance.
You could take a multivitamin supplement containing vitamin K2. There are dietary supplements containing both vitamin D and K2. These vitamins support cardiovascular and bone health. You’ll find a wide variety on iHerb.
It’s also tricky to get adequate amounts of vitamin D from diet. Vegans, vegetarians, and people who follow a plant-based diet may benefit the most from taking a vitamin D supplement.
For people taking blood thinners, it’s crucial to maintain a consistent intake of vitamin K.
Supplementation with vitamin K2 supplements, particularly those containing the menaquinone-7 (MK-7) form, can help ensure optimal levels of this nutrient in the body. MK-7 has a longer half-life compared to other forms of vitamin K2, allowing for less frequent dosing and potentially greater bioavailability.
What’s the Maximum Safe Intake?
Actually, there hasn’t been established a maximum safe dose of vitamin K. Even extremely high dosages of vitamin K are rather unlikely to cause toxicity or any adverse effects in healthy people.
Furthermore, high doses of vitamin K are pretty safe because most of it isn’t absorbed. The body retains only 30-40% of vitamin K. The rest is rapidly metabolized and excreted.
Side effects of too much vitamin K
Healthy people can safely consume high doses of vitamin K, either from food or supplements.
On the other hand, people who are under medication should consult their physician before taking dietary supplements containing vitamin K, or drastically changing their eating habits.
Vitamin K may interact with a few medications. For instance, heart patients who are taking blood thinners, such as warfarin (Coumadin®) should be very careful not to increase their vitamin K intake. Vitamin K can decrease the effect of warfarin, increasing the risk of blood clots! In this case, it’s vital to keep vitamin K intake consistent.
Do I need high dosages of vitamin K from supplements?
Vitamin K deficiency isn’t common. People who follow a well-balanced diet consume more vitamin K than the recommended daily intake.
It’s estimated that the average vitamin K intake from both food and supplements is about 160 mcg and 180 mcg for women and men, respectively.
Only people who follow a poor diet, low in vegetables, may consume low doses of vitamin K.
Moreover, certain drugs antagonize the activity of vitamin K and can lead to depletion of vitamin K. For instance, anticoagulants and antibiotics may have an adverse effect on vitamin K levels.
In fact, prolonged use of antibiotics can destroy vitamin K-producing bacteria in the gut, leading to low concentrations of vitamin K. In this case, vitamin K supplementation may be beneficial.
In contrast, people under anticoagulant medication need to maintain a consistent intake of vitamin K.
Furthermore, it can be difficult to get high doses of vitamin K2 from food. Especially, vegans and people who follow a plant-based diet don’t get any vitamin K2, as it’s only present in animal-based foods.
In this case, taking a multivitamin containing vitamin K2 may be beneficial. As plants don’t contain either vitamin D, people who follow a plant-based diet might benefit from a vitamin containing both vitamin D and K2. You’ll find a wide variety of dietary supplements with both vitamin D3 and K2 at the best prices on iHerb.
Do supplements exceed the maximum safe daily dosage?
First, you should prefer dietary supplements with vitamin K2. That’s the type of vitamin K that is hard to get from food.
Most dietary supplements contain vitamin K2 doses between 45-200 mcg, which is considered pretty safe.
Furthermore, according to studies, daily doses as high as 135 mg cause no adverse effects.
Always consult your healthcare provider before taking any dietary supplement, though.
Can I get High Doses from Food?
After all, the Japanese consume natto (fermented soybeans) for hundreds of years with no adverse effects. Natto is the richest food in vitamin K2, containing more than 100 mcg of vitamin K2 per 100g! This may be a reason why Japan has a lower fracture risk and stronger bone density than other countries!
Moreover, many studies have been performed using extremely high vitamin K2 dosages of 45,000-90,000 mcg. No toxic effects or adverse effects have been reported.
It’s estimated that 90% of the total vitamin K intake from our diet is vitamin K1. But, only 10-15% of vitamin K1 is absorbed by the body.
Health Benefits of Vitamin K
Vitamin K is a fat-soluble vitamin. It’s present in the liver and other body tissues, such as the brain, heart, pancreas, and bone.
Actually, Vitamin K is a family of compounds with a common chemical structure. There are two forms of this vitamin: vitamin K1 (phylloquinone) and vitamin K2 (menaquinones). We get vitamin K1 mainly from plant-based foods, while vitamin K2 is only found in certain animal-based, fermented foods and dietary supplements. Both types are vital for health.
Moreover, the human body produces small amounts of vitamin K2. Bacteria in the gut synthesize it.
Above all, vitamin K is important for our good health, as it’s necessary for the synthesis of proteins which clot the blood. A cut stops bleeding, partially due to vitamin K.
Also, vitamin K is involved in bone mineralization. It may help prevent fractures due to osteopenia and osteoporosis.
Some studies have linked vitamin K with higher bone mineral density, while other studies have found that vitamin K reduces the risk of fractures because it increases bone strength.
Both vitamins K1 and K2 protect from osteoporosis. According to studies, a vitamin K2 dosage of 45 mg could decrease the risk of hip fractures by 77%, while vitamin K1 dosages of 5 mg reduced clinical fractures by 50%. That’s why vitamin K2 is found in the supplements for osteoporosis prevention.[4,5,6]
Moreover, vitamin K2 isn’t present in many foods. Postmenopausal women could benefit from a supplement containing both vitamin K2 and vitamin D. Vitamin D also protects the bones!
Moreover, vitamin K may reduce the risk of coronary artery disease and all-cause mortality! Vascular calcification is a key risk factor for coronary heart disease. It reduces aortic and arterial elasticity. Vitamin K prevents vascular calcification.
Certainly, a diet rich in foods with vitamin K1 (green leafy vegetables) seems to suppress arterial calcifications and reduce the risk of cardiovascular events. However, getting high doses of both vitamin K1 and K2 is more effective for preventing and reversing arterial calcifications.
Furthermore, vitamin K seems to improve insulin sensitivity. Thus, it may prevent the development of diabetes and obesity. So, people who want to lose weight and people with diabetes should benefit from the regular consumption of green leafy vegetables.