Vitamin K Deficiency: Needs, Sources, and Useful Information

Vitamin-K-Mangel: Bedarf, Quellen und nützliche Informationen

Vitamins are substances that the body cannot produce itself. However, they are essential for a functioning organism. They must be ingested through food or supplements.

A lack of vitamin K - just like the lack of other vitamins, trace elements and minerals - cannot be compensated for by the body and restricts the function of certain processes. It should therefore be avoided at all costs. In this article you will find all the important information about vitamin K deficiency. Including what functions vitamin K has in the body, how a deficiency is determined and how you can remedy it.

the essentials in brief

  • The vitamin K group includes vitamins K1, K2 and K3. They are slightly modified in their respective chemical structure and only K1 and K2 occur naturally.
  • Vitamin K is important for various bodily functions. Among other things, it regulates blood coagulation, bone metabolism and can counteract vascular calcification.
  • A vitamin K deficiency can now be easily treated with appropriate supplements and a change in diet.

Definition: What is vitamin K?

Vitamin K is a collective term and includes the subgroups K1, K2 and K3. The vitamins from the K group, like the A, D and E vitamins, are fat-soluble. They are important for various functions in the body and activate anticoagulant factors and certain bone proteins.

The letter K was derived from the "coagulation" ability, clotting, for convenience. Because the lack of the vitamin impedes clotting.

Background: What you should know about vitamin K deficiency

In contrast to other vitamins (C, D, B12, etc.), vitamin K is rarely discussed and the layperson accordingly knows little about the organic compound. In the following we will go into the most important questions and provide basic knowledge about the group of K vitamins.

What functions does vitamin K have in the human organism?

The essential vitamin K takes on various functions in the body. The three most important are summarized below.

blood clotting

Vitamin K regulates the plasmatic coagulation process of the blood. In healthy people with a sufficient vitamin K level, cuts and other wounds can be closed quickly and thus protected against invading bacteria, viruses or fungi. This promotes wound healing.

a person's knee with plasters on it

Bleeding occurs even with small injuries to the skin, such as abrasions or cuts. With a plaster, the wound is quickly dry again and protected from penetrating bacteria. The colorful patterns put you in a good mood at the same time (Image source: Nathan Dumlao / unsplash)

In order for the healing to work well, vitamin K must convert so-called coagulation factors into their coagulation-effective forms. Only then are they helpful for closing a wound. To support this process, the anticoagulant proteins C and S in the liver are carboxylated by vitamin K at the same time. (1)

Acute vitamin K deficiency can lead to a certain susceptibility to bleeding. This susceptibility manifests itself, for example, in bleeding gums, increased bruising and, in particularly severe cases, bleeding can also occur in organs.

In any case, a defect should be taken seriously and appropriate steps taken.

bone metabolism

For a long time it was thought that calcium alone regulates healthy bone metabolism. Without vitamin K, however, calcium cannot or only insufficiently be incorporated into the bone structure. Together with vitamin D, K vitamins and calcium strengthen the bone substance.

Vitamin K is involved in bone mineralization, its properties make a significant contribution to bone formation and at the same time inhibit bone resorption, as a study from 2011 shows. (8th)

"If the body lacks vitamin K in the long term, bone density can decrease. A deficiency is associated with an increased risk of fractures.

The probability of developing osteoporosis is significantly lower with a normal vitamin K level than with a deficiency. Because athletes and women over the age of 40 in particular are part of the risk group for bone loss, they should ensure that they have an adequate intake of vitamin K. (2.9)

Apart from the functions of normal coagulation and bone metabolism, vitamin K protects against calcium deposits in vessels and thus prevents arteriosclerosis and varicose veins. A study from 2010 also shows the positive effects on cardiovascular diseases by reducing mortality. The vitamin is also linked to successful cancer prevention. (3,4,5)

Vitamin K1, K2 and K3 - What are the differences?

As already mentioned, several substances are hidden behind the term vitamin K. In the following table we have presented them for you and summarized their most important properties.

vitamin Designation Characteristics
K1 phylloquinone
  • is a part of the photosynthesis apparatus
  • found in the chloroplasts of green plants
  • occurs partly in their fruits
K2 menaquinone
  • is produced by certain bacteria
  • can also be found in the human intestine
  • can be partially synthesized from vitamin K1
K3 menadione
  • is synthetically produced
  • has no side chain before it is taken up by the organism
  • is only completed in the body

Basically, the effect of all three substances in the body is the same. Because of their slightly different chemical structure, however, they can unfold to different degrees. Vitamin K1 has a strong effect on blood clotting, K2 on bone metabolism.

Vitamin K3 is not found in natural foods or common dietary supplements. It is occasionally used in the manufacture of pet food.

What is the daily requirement of vitamin K?

How much vitamin K you should take depends on various factors, such as your biological sex and your age. Your needs will also change if you are pregnant or breastfeeding. The daily doses also differ for newborns and (small) children.

For your orientation, we have summarized the recommended guide values ​​of the German Society for Nutrition (DGE) in a table.

Gender age in years Daily requirement in micrograms per day
- 1 to 3 15
- 4 to 6 20
- 7 to 9 30
- 10-12 40
- 13-14 50
feminine 15 to 50 60
feminine 51+ 65
masculine 15 to 50 70
masculine 51+ 80

A guideline value of 60 micrograms of vitamin K per day applies to pregnant and breastfeeding women. An infant should get between 10 and 15 micrograms depending on their stage of development. Please discuss the individual needs of your newborn with your doctor.

What foods contain vitamin K?

Because vitamin K cannot be synthesized by the body itself, it has to be supplied externally, through food. Vitamin K is a plant vitamin and is therefore mostly found in leafy herbs and vegetables.

vegetables prepared for cooking

Tomatoes, asparagus and co. are not only delicious, they are full of healthy vitamins and nutrients. The more colorful you make your diet, the greater the variety of valuable vital substances. Vitamin K is mainly found in cabbage, broccoli and lettuce. (Image source: Gareth hubbard / unsplash)

The foods with the highest vitamin K content are the following:

Groceries Vitamin K content in micrograms per 100 grams
Kale 817
Chickpeas, dry 264
Cauliflower 236
broccoli 155
Lentils, dry 123
lettuce 109
edible bran 83
oatmeal 63


By the way: Unlike vitamin C, K1 is an insensitive and heat-stable nutrient. When foods high in vitamin K are exposed to air or heat (such as from cooking), there is little loss of vitamins. However, dark storage is recommended because of the sensitivity to light.

What are the symptoms of a vitamin K deficiency?

If there is an acute vitamin K deficiency, certain symptoms indicate this. So that you can develop a feeling for them, the most important ones are briefly named here.

  • Blood clotting disorders and increased tendency to bleed: If there is too little vitamin K in the body, the blood cannot clot well and it takes some time for a scab to form on a wound.
  • Hematoma (bruises): A susceptibility to bruising is associated with the coagulation disorder. With a lack of vitamin K, the connective tissue has difficulty stopping bleeding within the body. In extreme cases, organ bleeding can occur.
  • Decrease in bone density: Long-term vitamin K deficiency can result in bone loss and there is an increased risk of osteoporosis and fractures in the hip joint. (2)

A vitamin K deficiency can cause serious problems. In the next section we will explain how such a defect can arise at all.

What are the causes of a vitamin K deficiency?

A vitamin K deficiency can result from various causes. It is often not a result of diet, but only occurs when certain medications are taken or an illness breaks out. The following groups are particularly at risk:

  1. People with liver disease: If the liver is damaged, the effect of vitamin K can be reduced. Alcoholics and people who consume alcohol daily or several times a week are particularly at risk. This has a negative effect on the liver. Too few blood coagulation factors are formed and the coagulation process gets out of balance.
  2. People with disturbed intestinal flora: Inflammation in the gastrointestinal tract or an imbalance in the intestinal flora where there are too few vitamin K-producing bacteria can lead to a deficiency. This can also happen after taking certain antibiotics.
  3. People with metabolic disorders: In the case of diseases of the lipid metabolism, vitamin K often does not reach the organism sufficiently and is excreted again after ingestion. defects are to be expected.
  4. Infants: Vitamin K deficiency occurs relatively frequently in newborns and should not be underestimated due to the increased risk of deficient bleeding (7). On the one hand, breast milk is not the only source of vitamin K, and on the other hand, the bacterial self-formation in the intestine cannot take place at the beginning because it is initially sterile. The liver is also not fully developed at birth. It cannot synthesize the vitamin K-dependent proteins C and S to a sufficient extent.
  5. Animals: Pets can also suffer from a vitamin K deficiency. Dogs, cats and also horses are particularly affected if they cannot absorb enough vitamin K due to an unbalanced diet and/or certain restricted bodily functions in the liver or in the gastrointestinal tract. To prevent this, it is advisable to consult your veterinarian and choose your food carefully.

Potential risk groups are usually informed by their attending physician and advised on various remedies.

How is vitamin K deficiency diagnosed?

A nutrient deficiency is checked if it is suspected and is not part of standard prophylaxis. After previous illnesses have been ruled out and the intake of certain medications has also been checked for their interaction with vitamin K, the value is determined by blood test and compared with standard values.

drawing blood from a person

A blood test provides a great deal of information about your general condition. When taking blood, you only feel a small prick and then you get your results within a few days. The vitamin K level can also be detected in the blood. (Image source: Hush Naidoo / unsplash)

Because blood coagulation is closely linked to vitamin K, the quick test can also be used to determine a deficiency. This indicates how well a person's coagulation system works.

A healthy person with normal blood clotting has a Quick value of 100%. The tolerance is 30%. If the value is 70 or 130, there is still no evidence of a coagulation disorder."

In the quick test, blood is drawn from the patient. This is mixed with citrate and centrifuged so that the blood plasma settles. Blood coagulation is activated by adding calcium and heating the sample. From this point in time, the time is measured until so-called fibrin threads become visible in the sample.

With a modified procedure, the test can be carried out in a practice without a laboratory. The plasma is separated and a small steel ball is placed in the sample. After the addition of calcium and thromboplastin, fibrin threads form and the consistency of the plasma becomes gel-like. The sample rotates all the time and after some time the ball gets stuck in the gel. The measured time indicates the coagulation.

How does vitamin K work in case of an overdose?

In the case of an overdose of vitamin K, also known as hypervitaminosis, serious consequences are not to be expected. According to the current state of knowledge, vitamin K is free of side effects and an oversupply of K1 and K2 is not toxic.

However, newborns are exceptions. If they are given additional vitamin K, red blood cells can break down. The baby is at risk of anemia. (10)

Overdose can cause blood thickening in some cases. However, once the saturation limit has been reached, blood coagulation is no longer affected. An increased intake of vitamin K does not mean an increased risk of blood clots (thrombosis). (2)

If I supplement with vitamin D3, do I also have to take K2?

Information on the recommended intake of vitamin K when supplementing with vitamin D3 has been circulating for a number of years. There are combined preparations that contain D3 and K2 and advertise mutual interaction.

These recommendations are based on theoretical considerations to prevent vascular calcification and improve bone health. Vitamin D supports the body in absorbing calcium, vitamin K stores the mineral in the bones. If you have an increased intake of vitamin D, you should also take K2.

To date, no study has been able to confirm this hypothesis. There is a lack of reliable sources, which means that there is no basis for reliable statements on the combination of D3 and K2.

What are the antagonists of vitamin K?

In pharmacology, an antagonist is a substance that inhibits the effects of certain substances. The inhibition of action is often the sole task of an antagonist.

Vitamin K antagonists prevent the active form from being formed. They are used specifically to prevent thromboembolic diseases such as venous thrombosis or pulmonary embolism. The antagonists reduce the blood's ability to clot ("blood thinners").

The following substances belong to the vitamin K antagonists:

  • acenocoumarol
  • phenoprocoumon
  • warfarin

When taking these active ingredients, a normal intake of vitamin K through food is usually harmless, but additional supplementation is expressly not recommended.

The intake of vitamin K antagonists is not harmless if you are pregnant, have kidney or liver diseases, if you have an increased risk of bleeding or if you have ulcers in the digestive tract and should be discussed with your doctor urgently.

Vitamin K Deficiency: The Best Ways to Fix a Vitamin K Deficiency

We have summarized three solutions here so that you know what to do if you are faced with an impending vitamin K deficiency. You can implement all the tips quickly and easily without exposing yourself to any risk.

change nourishment

With a balanced diet, a lack of vitamin K is not to be expected. However, if you are affected by symptoms of a vitamin K deficiency, you can question your diet and, if necessary, adjust it with the advice of a doctor.

We recommend that you focus on green vegetables, legumes and whole grains. If your plate is particularly colorful and diverse, it contains many other nutrients in addition to vitamin K. They are all important for your health.

Supplement with preparations

If you do not see any results with a change in diet or if you find the change difficult, you can help with certain preparations. They are available in different dosage forms. As

  • drops
  • tablets
  • capsules
  • ampoules

you can take it orally, apply it locally to the skin as a serum or cream. When treating the skin, vitamin K does not penetrate the body. This dosage form is therefore only suitable for treating certain types of skin damage.

If you decide to supplement with vitamin K, follow the recommended dosage guidelines and look at reviews from buyers on the Internet.

You may have to experiment a bit before you find the right supplement for you.

Regular medical checks

If you suspect a vitamin K deficiency, you should contact your doctor and discuss the procedure in a personal conversation. As a rule, a quick quick test can already be carried out in practice. This tests your blood's ability to clot and a correspondingly low result can indicate a vitamin K deficiency.

If the test result is positive and you suffer from an acute vitamin K deficiency, the doctor will prescribe dietary supplements for you to compensate for the deficiency. After a specified period of time, a follow-up appointment should be made to discuss the success of the therapy and how to proceed.


A lack of vitamin K can have devastating consequences and should therefore not be underestimated. There should be some awareness of the potentially critical nutrient in infants in particular during the first twelve months of life. In adulthood, there is a risk of coagulation disorders, vascular calcification and osteoporosis. In rare cases, tissue and organ bleeding or blood clots occur, which can lead to death.

Luckily, treatment these days is uncomplicated and takes effect quickly. A balanced diet is usually enough to prevent a deficiency. Various ways of administering vitamin K preparations can also help people with intolerances or swallowing difficulties.


  1. Doolittle RF. Some Important Milestones in the Field of Blood Clotting. J Innate Immune. 2016;8(1):23-29. doi:10.1159/000442470
  2. SM Plaza, DW Lamson: Vitamin K2 in bone metabolism and osteoporosis. In: Alternative medicine review: a journal of clinical therapeutic. Volume 10, Number 1, March 2005, pp. 24-35, PMID 15771560
  3. Schurgers LJ, Spronk HM, Soute BA, Schiffers PM, DeMey JG, Vermeer C. Regression of warfarin-induced medial elastocalcinosis by high intake of vitamin K in rats. Blood. 2007;109(7):2823-2831. doi:10.1182/blood-2006-07-035345
  4. Ueland T, Gullestad L, Dahl CP, et al. Undercarboxylated matrix Gla protein is associated with indices of heart failure and mortality in symptomatic aortic stenosis. J Intern Med. 2010;268(5):483-492. doi:10.1111/j.1365-2796.2010.02264.x
  5. Nimptsch K, Rohrmann S, Kaaks R, Linseisen J. Dietary vitamin K intake in relation to cancer incidence and mortality: results from the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Heidelberg). Am J Clin Nutr. 2010;91(5):1348-1358. doi:10.3945/ajcn.2009.28691
  6. (Souci SW, expert W, herb H: The composition of the food, nutritional value tables, 7th revised edition. Medpharm Scientific Publisher, Stuttgart 2008.
  7. Phillippi JC, Holley SL, Morad A, Collins MR. Prevention of Vitamin K Deficiency Bleeding. J Midwifery Women's Health. 2016;61(5):632-636. doi:10.1111/jmwh.12470
  8. Yamaguchi M, Weitzmann MN. Vitamin K2 stimulates osteoblastogenesis and suppresses osteoclastogenesis by suppressing NF-κB activation. Int J Mol Med. 2011;27(1):3-14. doi:10.3892/ijmm.2010.562
  9. Booth SL, Broe KE, Peterson JW, et al. Associations between vitamin K biochemical measures and bone mineral density in men and women. J Clin Endocrinol Metab. 2004;89(10):4904-4909. doi:10.1210/jc.2003-031673
  10. Biesalski H, Bischoff S, Puchstein C, eds. 4th, completely revised and expanded edition. Stuttgart: Thieme; 2010. doi:10.1055/b-001-37
Back to blog
Vorheriger Beitrag

Nächster Beitrag

Leave a comment

Please note, comments need to be approved before they are published.