Vitamin K2

Vitamin K

The body needs the fat-soluble vitamin K to synthesize specific proteins that promote blood clotting and transport calcium from the blood vessels to the bones and other tissues.

Vitamin K occurs in two natural forms: vitamin K1 and vitamin K2. Vitamin K2 also includes several subtypes, each with its own molecular structure.

Where is it found?

Vitamin K1

Plants produce vitamin K1, or phylloquinone, and green leafy vegetables are particularly rich in it because it plays a role in photosynthesis. This form is active in the human body and possesses all the classic vitamin K properties. Roughly 90% of the vitamin K intake in a typical Western diet is vitamin K1.

Vitamin K2

Vitamin K2, or menaquinone, has an animal origin or is produced when bacteria create it through fermentation. By lengthening a side chain of the molecule, these bacteria generate new forms of vitamin K2, such as MK-4 and MK-7. Vitamin K2 is more active and effective in the body than vitamin K1 and is also a safe, well-absorbed form.

MK-4

In our diet, vitamin K2 MK-4 is of animal origin, for example from dairy. Achieving an adequate intake of MK-4, however, remains challenging, even when we consume plenty of pasture-raised dairy.

MK-7

Bacterial fermentation yields vitamin K2 MK-7, which occurs mainly in natto. Many supplements contain a vitamin K extract from natto. If you would rather eat natto to meet your daily vitamin K2 requirement, buy good natto from Nattodan, a Dutch natto producer.

Vitamin K for infants

The Health Council advises giving breast-fed babies 150 micrograms (µg) of vitamin K daily from day 8 up to and including week 12. Immediately after birth, the midwife administers 1,000 µg of vitamin K. This initial dose covers the requirement for the first week. During this period the newborn cannot yet produce the vitamin itself, so additional intake is necessary.

Daily intake from day 8

• Day 1 – 7: initial dose of 1,000 µg at birth (administered by the midwife).
• Day 8 – week 12: 150 µg extra vitamin K per day.

Role of vitamin K

Vitamin K is indispensable for normal blood clotting. Newborns have an increased need because they receive only small amounts of vitamin K during pregnancy, and their gut flora has not yet developed sufficiently to produce the vitamin themselves.

MenaQ7®, VitaMK7® and K2VITAL®

VitaMK7®

VitaMK7®, produced by Gnosis, is the active isomer of natural vitamin K2 with the highest bioavailability and the longest activity in the blood. Natto fermentation by the bacterium Bacillus subtilis produces the natural vitamin K2 in VitaMK7®. Gnosis uses CO₂ technology to create the product, entirely free of hazardous solvents and allergens.

VitaMK7® contains 99% “all-trans” vitamin K2 in the original biological structure.

MenaQ7®

MenaQ7® is a registered trademark of NattoPharma ASA.

MenaQ7®, the nature-identical synthetic vitamin K2, contains more than 98% “all-trans” MK-7 and is therefore a uniquely concentrated and pure substance. NattoPharma tests every batch of MenaQ7® produced.

Is vitamin K2 dangerous?

Vitamin K2 is not dangerous. On the contrary, it is one of the safest vitamins, even at very high doses.

Only people who use vitamin-K antagonists (anti-blood-clotting medicines / anticoagulants) should avoid vitamin K supplements.

Vitamin K2 and blood thinners

You can combine all forms of vitamin K with blood thinners that do not work through vitamin-K antagonism.

These vitamin-K-independent blood thinners are now prescribed most frequently, far more often than vitamin-K-antagonist anticoagulants.

However, do not use vitamin K until you have consulted your doctor. This avoids accidental use alongside vitamin-K-antagonist medicines.

Written by: Wouter Olthof
Reviewed by: Liesbeth Thoen

Updated on: 13 May 2025