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  4. Is Vitamin K2 An Underrated Vitamin?

Is Vitamin K2 An Underrated Vitamin?

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.

3 MIN READ — 02/26/2025

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.

Table of Contents

  • 01.

    What Is Vitamin K2 and Why Is It Important?

  • 02.

    Can Vitamin K2 Protect Against Heart Arrhythmias?

  • 03.

    What Are the Benefits of Vitamin K2?

  • 04.

    What Does Vitamin K2 Have to Do with Vitamin D3?

  • 05.

    How Much Vitamin K2 Do I Need Daily?

  • 06.

    Which Foods Contain Menquinone?

  • 07.

    Are There Any Side Effects from Taking Vitamin K2 Supplements?

At a Glance

  • 01.

    Vitamin K2 plays an important role in blood clotting. However, it is not scientifically proven that vitamin K2 protects against heart arrhythmias and osteoporosis.

  • 02.

    Sufficient intake of menquinone is possible for healthy individuals through a balanced diet. Supplements can help if necessary.

  • 03.

    Sources of K2 are exclusively animal and fermented foods.

What Is Vitamin K2 and Why Is It Important?

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.

Can Vitamin K2 Protect Against Heart Arrhythmias?

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.

What Are the Benefits of Vitamin K2?

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.

What Does Vitamin K2 Have to Do with Vitamin D3?

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.

How Much Vitamin K2 Do I Need Daily?

The German Nutrition Society (DGE) recommends the following daily amounts of vitamin K2 for sufficient intake:

  • Women aged 15 to 51: 60 micrograms
  • Men aged 15 to 51: 70 micrograms
  • Women over 51: 65 micrograms
  • Men over 51: 80 micrograms
  • Children in their first 4 years: 15 micrograms
  • Children aged 4 to 7: 20 micrograms
  • Children aged 7 to 10: 30 micrograms
  • Children aged 10 to 13: 40 micrograms
  • Adolescents aged 13 to 15: 50 micrograms

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.

Which Foods Contain Menquinone?

Unlike vitamin K1, which is found in plant-based foods, K2 is primarily found in animal and fermented foods. K2 sources include:

  • Meat and offal
  • Eggs
  • Milk and dairy products
  • Sauerkraut
These Foods Contain Menquinone

These Foods Contain Menquinone

Are There Any Side Effects from Taking Vitamin K2 Supplements?

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.

Article Sources

Deutsche Gesellschaft für Ernährung e. V. (DGE): Vitamin K, 2020
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

Bundeszentrum für Ernährung: Vitamin-K-Gabe für Säuglinge empfohlen
https://www.bzfe.de/service/news/aktuelle-meldungen/news-archiv/meldungen-2022/juni/vitamin-k-gabe-fuer-saeuglinge-empfohlen/

Europäische Behörde für Lebensmittelsicherheit (efsa): Referenzwerte für die Nährstoffzufuhr: EFSA veröffentlicht Empfehlungen zu Vitamin K, 2017
https://www.efsa.europa.eu/de/press/news/170522-1

Europäische Behörde für Lebensmittelsicherheit (efsa): Vitamin K2 added für nutritional purposes in foods for particular nutritiional uses, food supplements and foods intended für the general population and Vitamin K2 as a source of vitamin K added für nutritional purposes to foodstuffs, in the context of Regulation (EC) N° 258/97[1] – Scientific Opinion of the Panel on Dietetic Products, Nutrition and Allergies, 2008
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, 2022
https://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/

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Food supplements are not a substitute for a balanced and varied diet and a healthy lifestyle. Do not exceed the indicated daily intake. Keep out of reach of children. Please inform and consult your doctor before consuming this product. Not suitable for children and adolescents under 18 years, pregnant or breastfeeding women. Refrain from taking other food supplements containing zinc. Persons taking anticoagulant medication should seek medical advice before consuming vitamin K-containing supplements.

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§ In a third-party, observational study conducted on 35 healthy adults ages 25-48 assessing the self-perceived efficacy of AG1 over the course of 3 months. The study was conducted on a similar version of AG1's continually evolving formulation. The study results are transferable because of comparable ingredients and amounts.

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a. In a triple-blind, randomised, placebo-controlled parallel-designed clinical trial evaluating nutrient biomarkers and microbiome shifts in 105 healthy adults ages 20-59 over the course of 12 weeks.
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c. In a double-blind, randomised, placebo-controlled 2-week cross-over clinical trial assessing microbiome shifts of 24 healthy adults with occasional GI distress ages 26-59.
d. In a double-blind, randomised, placebo-controlled cross-over clinical trial assessing bioavailability in 16 healthy adults ages 18-42 over the course of 8 hours.
The studies were conducted on a similar version of AG1's continually evolving formulation. The transferability of the study results is ensured because of comparable ingredients and amounts.

◊ Key health benefits:

(1) Immune system: With vitamins A, C, B6 and B12 as well as folate, zinc, copper and selenium, AG1 contributes to the normal function of the immune system. Vitamin C contributes to maintain the normal function of the immune system during and after intense physical exercise. 200 mg Vitamin C taken daily in addition to the recommended daily dose (80 mg) contributes to the normal function of the immune system during and after intensive physical activity.

(2) Energy levels: Vitamins C, B6, B12, riboflavin, niacin, pantothenic acid and magnesium contribute to normal energy-yielding metabolism and to the reduction of tiredness and fatigue. Magnesium contributes to electrolyte balance. Biotin, zinc and chromium contribute to normal macronutrient metabolism.

(3) Digestion: Calcium contributes to the normal function of digestive enzymes. With vitamin A, biotin, riboflavin and niacin, AG1 contributes to the maintenance of normal mucous membranes (e.g. intestinal mucosa).

(4) Focus; Mental performance; Psychological function; Nervous system: With pantothenic acid, AG1 contributes to normal mental performance. Zinc contributes to normal cognitive function. With vitamins C, B6, B12, B1, B3 and B7 AG1 contributes to normal psychological function and to normal functioning of the nervous system. Calcium contributes to normal neurotransmission.

‡ Additional health benefits:

(5) Muscles: With calcium and magnesium, AG1 contributes to normal muscle function.

(6) Cell Protection: With vitamins E and C as well as riboflavin, zinc, copper and selenium, AG1 contributes to the protection of cells from oxidative stress. Phosphorus contributes to normal function of cell membranes. Folate, Vitamin B6 and B12 contribute to normal homocysteine metabolism.

(7) Skin, hair & nails: With vitamins A, as well as riboflavin, niacin, biotin and zinc, AG1 contributes to the maintenance of normal skin. Vitamin C contributes to normal collagen formation for the normal function of skin. Copper contributes to normal connective tissue. Vitamin B7, zinc and selenium contribute to the maintenance of normal hair. Zinc and selenium contribute to the maintenance of normal nails.

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