Vitamin K Foods: The Best Sources at a Glance

Vitamin K is found above all in green leafy vegetables such as kale, spinach and broccoli, but also in some plant oils and fermented foods – anyone who regularly eats green vegetables usually covers their needs well. Vitamin K contributes to normal blood clotting and to the maintenance of normal bones. In this guide you will find a clear list of the best vitamin K providers with orientation values, learn the difference between the two forms K1 and K2, how much you need per day, and get practical tips on how to noticeably improve the absorption of the fat-soluble vitamin from food.

Why vitamin K is important

Vitamin K is a fat-soluble vitamin and performs recognised functions in the body: vitamin K contributes to normal blood clotting and contributes to the maintenance of normal bones. It is thus involved in fundamental processes that are important for a healthy metabolism. Because the vitamin is fat-soluble, it is absorbed considerably better together with a little fat from food – a salad with oil is ideal here. The body can store vitamin K only to a limited extent, which is why a regular intake spread over the week through food makes more sense than single large amounts on a few days. A varied diet with plenty of green vegetables and high-quality oils is the simplest and most reliable basis for a good supply – expensive preparations are usually not necessary for healthy people.

Vitamin K1 and K2: the difference

Vitamin K occurs in two main forms. Vitamin K1 (phylloquinone) comes predominantly from plant sources, above all green leafy vegetables, and makes up the largest part of our intake through food. Vitamin K2 (menaquinone), on the other hand, occurs in fermented and some animal foods, for example in sauerkraut, certain cheeses and the Japanese natto, which is particularly rich in K2. In addition, bacteria in the intestine form part of the vitamin K2. Both forms contribute to the recognised functions. For most people, the plentiful intake of K1 through green vegetables is the most important lever, while K2 through fermented foods sensibly supplements the intake.

The best vitamin K foods

The following values are orientation figures for vitamin K1 per 100 grams and can vary depending on variety, season and preparation:

• Kale: around 800 µg – one of the richest providers of all
• Spinach: about 300–500 µg
• Chard: around 300 µg
• Parsley: very high, but eaten in small amounts
• Broccoli: about 150–250 µg
• Brussels sprouts: around 175 µg
• Lettuce and lamb's lettuce: 100–200 µg depending on variety
• Rapeseed oil and olive oil: notable amounts, good for dressing
• Fermented foods such as sauerkraut: additionally provide vitamin K2

Just one portion of kale or spinach covers, on paper, a multiple of the recommended daily amount – vitamin K is thus extremely well attainable through the diet. The exact contents vary depending on cultivation, harvest time and storage, but the ranking remains the same: dark green leafy vegetables are clearly at the top, followed by cabbage vegetables and salads.

How much vitamin K you need per day

As orientation, expert societies name estimated values for adults in the range of about 60 to 80 micrograms per day, depending on gender and age. This amount is usually easy to reach through a normal mixed diet with regular green vegetables – often already with a single decent portion. Unlike with some other vitamins, a pronounced deficiency is rare in healthy adults with a balanced diet. Important to know: the values mentioned are guide figures and not rigid limits that you have to calculate exactly every day. Anyone who eats a varied diet and firmly builds green leafy vegetables into the weekly plan usually needs to worry little about the vitamin K supply in everyday life. Newborns form a known exception here and are routinely medically supervised for good reason, since their stores are still poorly filled at birth.

Improving absorption: practical tips

Since vitamin K is fat-soluble, a little fat noticeably improves absorption from the vegetables. So add a high-quality oil to your salad or sauté the vegetables with a dash of oil. Vitamin K is comparatively stable towards heat, so that gentle cooking reduces the contents only slightly – you should nevertheless avoid long boiling in a lot of water, because unnecessary nutrients are lost in the process. Combine different green vegetables over the week to benefit from the variety. Fresh, dark green leaves usually contain more vitamin K than pale or long-stored ones. Fermented foods such as sauerkraut additionally supplement the intake with the K2 form. Anyone who steams their vegetables instead of boiling them in a lot of water and refines them with oil just before serving gets the most out of them.

When supplementation can make sense

For most healthy people, targeted supplementation is not necessary, because the diet reliably covers the requirement. In certain situations, however, the requirement or the supply can be changed, for example with illnesses that disturb fat absorption in the intestine, with certain medications, or with newborns, who are routinely medically supervised for good reason. One point is particularly important: if you take blood-thinning medications of the vitamin K antagonist type, the vitamin K intake can influence their effect. In this case it is not about avoiding vitamin K, but about keeping the intake as even as possible. Therefore do not strongly change your diet nor take preparations without first discussing this with your doctor. For everyone else, the principle remains simple: eat green vegetables regularly and do not worry.

Common misconceptions about vitamin K

Some misunderstandings persist around vitamin K. A widespread error is that vitamin K and potassium are the same – in fact these are completely different nutrients that only coincidentally match in the abbreviation K. Another error concerns colour: not every green food is automatically rich in vitamin K, but dark green leaves reliably provide more than pale varieties. The assumption that you absolutely have to take vitamin K via preparations also rarely applies to healthy people, because the diet is usually sufficient. Finally, many believe that long cooking completely destroys the vitamin – vitamin K, however, is relatively heat-stable; it reacts more sensitively to very long soaking. Anyone who knows these points makes the better decisions in everyday life.

Building vitamin K cleverly into everyday life

The simplest way to a good supply is routine: plan a portion of green vegetables on several days of the week, whether as a side dish, in a smoothie, in soup or as a salad. Kale and spinach can be cooked well in advance and frozen, so that you have a quick source at hand even outside the season. Fresh herbs such as parsley enhance many dishes and additionally provide vitamin K. Anyone who shops seasonally gets dark green leafy vegetables particularly fresh and nutrient-rich. Add fermented foods for the K2 form and always add a little oil so that absorption succeeds. A green smoothie in the morning, a leaf salad at lunch and steamed cabbage vegetables in the evening already easily cover the requirement. In this way you supply yourself quite incidentally through the plate, without being reliant on preparations.

Frequently Asked Questions (FAQ)

Which food contains the most vitamin K?

Kale is one of the richest sources with around 800 micrograms per 100 grams. Spinach, chard and parsley also provide a lot of vitamin K1. Just a normal portion usually clearly covers the recommended daily amount.

How much vitamin K do I need per day?

For adults, expert societies name estimated values of about 60 to 80 micrograms per day, depending on gender and age. This amount can be reached well with regular green vegetables in a mixed diet.

Is vitamin K destroyed during cooking?

Vitamin K is relatively stable towards heat, so that gentle cooking reduces the contents only slightly. Avoid long boiling in a lot of water and add a little fat, since this improves the absorption of the fat-soluble vitamin.

Can I take in too much vitamin K through food?

Through normal foods, a harmful oversupply is not to be expected in healthy people. Caution is however advised with blood-thinning medications – here you should coordinate diet and preparations with a doctor.

Does a plant-based diet contain enough vitamin K?

Yes. Vitamin K1 comes above all from plant sources, foremost green leafy vegetables. Fermented foods such as sauerkraut additionally provide the K2 form, so that a plant-focused diet is also well supplied.