
Many refer to vitamin K2 as the bone vitamin. Discover what this vitamin can really do, why it's important for vitamin D, and where to find it.
Vitamin K2 might just be the unsung hero of the vitamin world. Often overshadowed by its siblings, K2 is finally getting the attention it deserves for its potential to support bone strength and heart health. But is it really the powerhouse it's claimed to be? In this article, we’ll dive into the benefits of Vitamin K2, why it’s important for vitamin D and where you can find this essential nutrient in your diet.
At a Glance
Vitamin K2 plays an important role in blood clotting. However, it is not scientifically proven that vitamin K2 protects against heart arrhythmias and osteoporosis.
Sufficient intake of menquinone is possible for healthy individuals through a balanced diet. Supplements can help if necessary.
Sources of K2 are exclusively animal and fermented foods.
Vitamin K2, also known as menquinone, is one of the water-soluble vitamins and is essential for blood clotting as well as maintaining normal bone density. Along with vitamin K1 (phylloquinone), it plays an important role in many bodily functions. Since our bodies can only store vitamin K2 to a limited extent, it needs to be regularly obtained through diet.
In Germany and Europe, it is generally assumed that a balanced diet typically ensures sufficient intake of menquinone. However, certain groups may be at a higher risk of deficiency due to unbalanced diets or specific medications.
You may often read or hear that vitamin K2 can prevent heart arrhythmias or osteoporosis. However, this is not scientifically proven. This was also concluded by a study from the European Food Safety Authority, which found that previous studies on vitamin K2 and heart arrhythmias were not sufficiently conclusive.
Vitamins K1 and K2 mainly contribute to the formation of protein proteins. These proteins, in turn, support blood clotting, kidney function, and bone density. Various studies have also shown that women with low vitamin K intake have a higher risk of bone fractures. Vitamin K2 also contributes to calcium metabolism and enhances the positive effects of Vitamin D3.
Another important property of K vitamins was discovered by the Helmholtz Centre in Munich in collaboration with national and international research institutions in 2022. It was found that these vitamins play a crucial role in combating natural cell death (ferroptosis). Studies showed that vitamins K1 and K2 help protect tissues from ferroptosis. However, this effect cannot be achieved through dietary intake alone. Instead, the researchers' discovery plays a significant role in developing specific pharmaceutical products.
Vitamin K2 and vitamin D3 work closely together to support your bone health. While vitamin D3 promotes the absorption of calcium from food, vitamin K2 ensures that this calcium is properly incorporated into the bones. Without sufficient vitamin K2, calcium could deposit in the arteries, potentially leading to vascular calcification. Therefore, it is important that both vitamins are present in a balanced ratio in the body.
The German Nutrition Society (DGE) recommends the following daily amounts of vitamin K2 for sufficient intake:
Ensuring sufficient vitamin K2 intake is particularly important for infants in their first 4 months of life. They do not receive enough of the vitamin and are therefore given a vitamin K supplement immediately after birth to protect against bleeding tendencies.
Unlike vitamin K1, which is found in plant-based foods, K2 is primarily found in animal and fermented foods. K2 sources include:

These Foods Contain Menquinone
An overdose of vitamin K2 is not possible since the body excretes any unneeded menquinone. Generally, K vitamins do not cause side effects because they only support normal blood clotting without causing blood thickening.
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https://www.dge.de/wissenschaft/referenzwerte/vitamin-k/
Verbraucherzentrale: Vitamin-K-Produkte - was ist sinnvoll? 2023
https://www.klartext-nahrungsergaenzung.de/wissen/lebensmittel/nahrungsergaenzungsmittel/vitaminkprodukte-was-ist-sinnvoll-26574
Bundesinstitut für Risikobewertung (BfR): Höchstmengenvorschläge für Vitamin K in Lebensmitteln inklusive Nahrungsergänzungsmitteln, 2015
https://www.bfr.bund.de/cm/343/hoechstmengenvorschlaege-fuer-vitamin-k-in-lebensmitteln-inklusive-nahrungsergaenzungsmitteln.pdf
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https://www.efsa.europa.eu/en/efsajournal/pub/822
Europäische Behörde für Lebensmittelsicherheit (efsa): Scientific Opinion on the substantiation of a health claim related to vitamin K2 an contribution to the normal vunction of the heart and blood vessels (ID 125, further assessment) pursuant to Article 13 /1) of Regulation (EC) No 1924/2006, 2012
https://www.efsa.europa.eu/de/efsajournal/pub/2714
Helmholtz-Zentrum München: Vitamin K verhindert Zelltod: Forscher entdecken neue Funktion eines lange bekannten Moleküls, 2022https://www.helmholtz-munich.de/newsroom/news/artikel/vitamin-k-verhindert-zelltod-forscher-entdecken-neue-funktion-eines-lange-bekannten-molekuels
Yan Quanxiang u. a.: The biological responses of vitamin K2: A comprehensive review, 2023, in PubMed
https://onlinelibrary.wiley.com/doi/10.1002/fsn3.3213
Gerry Kurt Schwalfenberg: Vitamins K1 and K2: The Emerging Group of Vitamins Required for Human Health, 2017, in PubMed
https://onlinelibrary.wiley.com/doi/10.1155/2017/6254836
Ming Zhou, Shiliang Han, Wenpeng Zhang, Daniel Wu: Efficacy and safety of vitamin K2 for postmenopausal women with osteoporosis at a long-term follow-up: meta-analysis and systematic revies, 2022, in PubMed
https://pubmed.ncbi.nlm.nih.gov/35711002/