How does vitamin K affect the body?

Vitamin K is a fat-soluble vitamin. "K" comes from the German word "koagulation" - coagulation, that is, coagulation, thickening. Coagulation in the body refers to the process of hematopoiesis. Vitamin K is necessary for the functioning of a number of proteins involved in the blood clotting process. How does vitamin K affect the body and why is it needed?

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More about vitamin K

Vitamin K is not a single chemical substance, but a family of chemically related substances that go under the general name "vitamin K." The vitamin has undergone major changes in the scientific understanding of its chemistry and function over the past 30 years. In the past, members of the vitamin K family were traditionally referred to as vitamin K1, vitamin K2, and vitamin K3. This terminology has largely replaced another set of terms to describe what has now been identified as a more complex set of vitamin K compounds.

Other names for it today are Menadione; Menaphthon; menaquinone; Phylloquinone

Types of Vitamin K

All types of vitamin K belong to a category of large chemicals called naphthoquinones. Within this category of naphthoquinones, there are two main types of vitamin K. The first type of vitamin K is phylloquinones, which are made by plants. The second main type, called menaquinones, are made by bacteria. The only exception to this rule involves a special group of bacteria called cyanobacteria, which make phylloquinones instead of menaquinones.

Contrary to some previous scientific assumptions, we get most of our dietary vitamin K as phylloquinones from plant foods. In fact, up to 90% of our dietary vitamin K comes in this form, and more than half of our vitamin K comes from vegetables, especially green leafy vegetables. Many different types of bacteria in our gut can create vitamin K as menaquinones. Although vitamin K synthesis in our digestive tract may contribute to our need for a particular type of vitamin K, we get less than previously thought.

What are the functions of vitamin K?

Vitamin K has several very useful functions for the body, the main one being hematopoiesis.

Vitamin K contributes to normal blood clotting

From a medical research perspective, vitamin K is highly respected by all medical professionals for its role in healthy blood clotting. That's why the use of the letter "K" in the name of this vitamin originally came from the German koagulation.

Although blood clotting may not be considered a body process that is essential to our daily functioning, it is, in fact, essential. Whenever we get a wound on the skin, sufficient blood clotting ability is needed to heal the wound and prevent excessive bleeding.

But we don't want too much blood clotting because when we're not injured, we don't want clots forming in our cardiovascular system and blocking blood vessels from functioning correctly. Vitamin K is one of the key nutrients for maintaining our blood clotting ability at the right level.

The process of blood clotting

Vitamin K is right at the center of the clotting process. If clotting factors are to be used to successfully close a wound, it must somehow stick to nearby tissue surfaces. This “stickiness” is given to them by a chemical process called carboxylation. One of the amino acids for clotting is called glumatic acid, which is a component of blood clotting. A second enzyme, warfarin, works as an anticoagulant and interrupts this process by blocking one of these enzymes (epoxide reductase).

When this enzyme is blocked, vitamin K cannot be processed to help the blood clot until it reaches its proper stickiness. For individuals with an excess tendency to form clots, an anticoagulant such as warfarin can be life-saving. Discoveries about the properties of warfarin led to our modern understanding of vitamin K as a key substance for healthy blood clotting.

Vitamin K protects weakened or damaged bones

Vitamin K's bone health benefits have been well studied. The most compelling research shows protection against bone fractures when vitamin K is consumed in adequate amounts.

Individuals who do not consume enough vitamin K have a higher risk of fractures. In addition, for women who have gone through menopause and are experiencing unwanted bone loss, vitamin K may help prevent future fractures. These bone benefits associated with vitamin K intake appear to depend on two main mechanisms.

Why are osteoclasts needed?

The first of these mechanisms involves a type of bone cell called osteoclast. Osteoclasts are bone cells responsible for bone demineralization. They help take minerals from the bones and make them available for other functions in the body. While the activity of these cells is important for health, a person does not want too many osteoclasts (or too much osteoclast activity), as this imbalance will mean too much bone demineralization.

Two important mechanisms of vitamin K

Vitamin K allows our bodies to keep this process under control. One form of vitamin K (MK-4, also called menatetrenone) has repeatedly been shown to block the formation of too many osteoclasts and possibly initiate programmed cell death (a process called apoptosis).

The second mechanism involves the role of vitamin K in a process called carboxylation. For our bones to be optimally healthy, one of the proteins found in bone, the protein osteocalcin, needs to be chemically altered through a process called carboxylation.

Osteocalcin

Osteocalcin is not just a typical bone protein. It is a protein associated with bone mineral density (BMD) and for this reason is often measured in our blood when doctors are trying to figure out if our bones are healthy. When there is too little osteocalcin protein, our bones are at increased risk of fracture. This unwanted risk seems to be especially important in relation to hip fracture. Scientists have found that vitamin K can significantly improve the situation.

Since vitamin K is necessary for the normal activity of the enzyme carboxylase, which allows the process of carboxylation of osteocalcin proteins in our bones, vitamin K can repair bones and strengthen their composition.

Vitamin K prevents calcification of blood vessels or heart valves

A common problem in many forms of cardiovascular disease is unwanted calcification, a buildup of calcium in tissues that usually goes unnoticed. This calcium buildup causes the tissues to become too hard and stop functioning properly. When calcium builds up in the arteries, it is commonly referred to as hardening of the arteries.

A direct way to slow the buildup of calcium in artery walls is to maintain an adequate supply of a special protein called MGP. MGP, or matrix Gla protein, directly blocks the formation of calcium crystals in blood vessels. In other words, the heart-protective benefits of MGP in preventing calcification are dependent on vitamin K.

Researchers have found that people with a vitamin K deficiency have a higher risk of clogged arteries than people with healthy vitamin K intake.

Other Important Roles of Vitamin K

Researchers continue to explore the wide range of medicinal and supportive roles of vitamin K. At the forefront of this research are its roles in three main areas:

1. protection against oxidative damage;
2. proper regulation of the body's inflammatory response,
3. support for the brain and nervous structure of the body.

In terms of protecting against oxidative damage, vitamin K does not work directly as an antioxidant in the same way as other antioxidant vitamins (such as vitamin E and vitamin C). However, phylloquinone and menaquinone (forms of vitamin K) are useful in protecting cells, especially nerve cells, from oxidative damage.

In the context of an inflammatory response, several markers of pro-inflammatory activity, including, for example, the release of interleukin-6 (IL-6), are significantly reduced when the body has sufficient vitamin K. Finally, vitamin K is known to be necessary for the synthesis of a very important component of the brain and nervous system called sphingolipids (translated as “squeeze, compress”). These fats are critical in the formation of the myelin sheath, which forms the outer covering around the nerves, and both forms of the vitamin

K - phylloquinone and menaquinone, have been found to be effective in supporting the synthesis of these key nerve components. All of these roles of vitamin K were discovered primarily in laboratory studies on animals and in laboratory studies on human cell samples.

What are the symptoms of vitamin K deficiency?

People with vitamin K deficiency primarily have symptoms related to problematic blood clotting or bleeding. These symptoms may include heavy menstrual bleeding, bleeding gums, gastrointestinal bleeding, nosebleeds, easy bruising, blood in the urine, prolonged clotting time, bleeding, anemia.

The second problem with vitamin K deficiency is bone problems. These symptoms can include bone loss (osteopenia), decreased bone mineral density (osteoporosis), and fractures, including common age-related fractures. For example, hip fractures. Vitamin K deficiency causes calcium to be deposited in soft tissue. This calcification can lead to clogged arteries or problems with heart valve function.

What are the symptoms of vitamin K toxicity?

Because no adverse effects have been reported from higher dietary intakes of vitamin K, there are no documented symptoms of vitamin K toxicity. In animal studies, vitamin K has been given in amounts as high as 25 mcg per kilogram of body weight (or for a 154 kg adult, the equivalent of 1,750 mcg of vitamin K) without detectable toxicity. For these reasons, the Institute of Medicine of the National Academy of Sciences decided not to set a tolerable upper limit for vitamin K when it revised its public health recommendations for this nutrient in 2000.

One important exception to the toxicity results is the synthetic form of vitamin K, called menadione. Although this form of vitamin K can sometimes be converted by the body into non-toxic forms, studies have shown that there are undesirable risks that come with consuming menadione. These risks include excessive oxidative stress to the body and, as a result, damage to various types of cells, including kidney and liver cells.

Based on these findings, the United States does not allow vitamin K to be sold as a dietary supplement in the form of menadione. Menadione is also known as vitamin K3.

How does cooking affect vitamin K?

Vitamin K is generally retained fairly well after cooking or storing foods. Some sources warn against freezing vegetables due to potential loss of vitamin K, but has anyone seen studies documenting this risk?

As for cooking, research at the U.S. Department of Agriculture's Nutritional Data Laboratory in Beltsville has shown that heating does not cause any significant loss of vitamin K in vegetables. In some cases, cooking increases measurable amounts of vitamin K.

Forms of vitamin K are found in chloroplasts, components of plant cells, and cooking might break down the plant cell walls and release some forms of vitamin K. Releasing vitamin K from chloroplasts increases the availability of vitamin K in the body. However, cooking vegetables does not negatively affect their vitamin K content in any way.

Research shows that freezing and storing vegetables and fruits and heat treatment of these products do not cause excessive loss of vitamin K. Therefore, vitamin K does not depend on the consumption and processing of plant materials.

What factors contribute to vitamin K deficiency?

Any health problem, particularly with digestion and nutrient absorption, can contribute to vitamin K deficiency. These problems include conditions such as inflammatory bowel disease, ulcerative colitis, celiac disease, short bowel syndrome, and digestive tract surgery (such as bowel resection). Problems with pancreatic, liver, and gallbladder function can also increase the risk of vitamin K deficiency.

Because our gut bacteria help us absorb vitamin K, any painkillers that alter our normal gut bacteria can compromise our vitamin K levels. Antibiotics would be at the top of this list, but so would anticonvulsants, sulfa drugs, and salicylate-containing drugs. If you regularly use any of these drugs, we recommend talking to your doctor about their potential impact on your vitamin K.

There is some evidence that the aging process itself may contribute to vitamin K deficiency. The reasons for this - the potential links between aging and vitamin K - are unclear. Changes in general metabolism may be involved in this list, along with other, more specific changes directly related to vitamin K. It may be especially important to carefully assess our vitamin K intake as we age.

How do other nutrients interact with vitamin K?

Research on nutrients that interact with vitamin K has traditionally focused on the major fat-soluble vitamins, namely vitamins A, E, and D. Unfortunately, this research has shown mixed results. People on anticoagulant treatment report that their anticoagulant therapy and vitamin K levels are affected by high doses of vitamin E.

For this reason, both vitamin K and vitamin E intake are needed for people undergoing anticoagulant medication. This intake is determined with the help of a doctor. In healthy people who do not consume vitamin E, decreased vitamin K levels have been shown. However, in some cases, higher doses of vitamin E (above 1000 mg) have been shown to interfere with the functions of vitamin K at this stage and often lead to bleeding.

Largely based on these hemorrhagic effects, the U.S. National Academy of Sciences in 2000 set the tolerable upper limit (UL) for vitamin E at 1,000 milligrams per day.

Because calcium metabolism can be significantly affected by both vitamin D and vitamin K, researchers suspect some key interactions between these two fat-soluble vitamins. However, the exact nature of this interaction has not yet been determined.

Excess supplemental vitamin A (retinol) has been shown to interfere with the blood clotting ability of vitamin K. Vitamin A and vitamin K levels in adults are typically 10,000 IU (3,000 mcg) or higher.

Who needs higher doses of vitamin K?

Vitamin K may play a role in the prevention and/or treatment of the following diseases:

• Anticoagulant therapy
• Bone fracture
• Chronic liver diseases
• Cystic fibrosis
• Hardening of the arteries
• Inflammatory bowel disease
• Liver cancer
• Pancreatic cancer
• Kidney stones
• Nausea and vomiting during pregnancy
• Osteopenia (bone loss)
• Osteoporosis (decreased bone mineral density)
• Thrombosis

What foods provide vitamin K?

Excellent sources of vitamin K include parsley, kale, spinach, Brussels sprouts, Swiss chard, beans, asparagus, broccoli, collard greens, mustard greens, turnip greens, collard greens, thyme, romaine lettuce, sage, oregano, cabbage, celery, cucumbers, leeks, cauliflower, tomatoes, and blueberries.

Cheeses

Fermentation of foods can be particularly useful for increasing vitamin K levels. One food that can increase vitamin K levels through fermentation is cheese. Swiss Emmental cheese and Norwegian Jarlsberg cheese are examples of cheeses that are fermented by the bacteria Proprionibacterium. These bacteria can create large amounts of vitamin K.

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Soybeans

A very special place should be given to fermented soy products. Bacillus subtilis is a lesser-known microorganism used in the fermentation process of soybeans. One fascinating aspect of fermented soy products is the potential ability of these bacteria to remain alive in our lower intestines after these products are consumed and supply us with vitamin K2.

As with the Japanese diet, fermented soy products are the most common source of vitamin K. Meat and eggs are the most common food sources of another form of vitamin K2. Remember, all forms of vitamin K, including K2, contribute greatly to our health!

Salads

Many types of lettuce contain high amounts of vitamin K. It's worth noting that on an ounce-for-ounce basis, romaine lettuce may have about four times more vitamin K than head lettuce, according to research conducted by the U.S. Department of Agriculture.

Because vitamin K is fat-soluble, nutrients and foods tend to have higher amounts of vitamin K when the food has less water. For example, tomato paste has more vitamin K than fresh tomatoes.

Sometimes the outer leaves of plants can have a more concentrated content of vitamin K than the inner leaves. For this reason, it is worthwhile to very carefully and gently peel these vegetables when rinsing them under clean running water, and also to peel other leaves and include them in food.

Vitamin K Depot

Vitamin K is a fat-soluble vitamin, so our body stores it in fat tissue and the liver.

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Interesting facts about vitamin K

• Vitamin K is used to reduce the risk of bleeding in liver disease.
• In the United States, Canada, the United Kingdom and many other countries, all newborns were given injections of vitamin K to prevent the possibility of bleeding, especially in the brain.
• Babies are born without any bacteria in their gut and do not get enough vitamin K from breast milk to supply the body.
• Although vitamin K deficiency in newborns is very rare, it is dangerous, so doctors in developed countries give them injections.
• Infants at greatest risk of vitamin K deficiency are those born prematurely. Mothers are often given oral forms of vitamin K for 2 weeks before delivery to reduce the risk of preterm birth.
• There is growing evidence that vitamin K improves bone health and reduces the risk of bone fractures, especially in postmenopausal women who are at risk of developing osteoporosis.
• Studies in men and women have also shown that vitamin K helps with bone health in athletes.
• Foods that contain significant amounts of vitamin K include beef liver, green tea, turnip greens, collard greens, broccoli, kale, spinach, asparagus, lettuce, and dark green salad. The chlorophyll substances in plants that give them their green color contain vitamin K.
• Freezing foods can destroy vitamin K, but cooking does not affect its content.
• People whose bodies cannot absorb enough vitamin K due to gallbladder disease or biliary tract infection, cystic fibrosis, celiac disease, or Crohn's disease may benefit more from a multivitamin containing vitamin K than from vitamin K alone.

Daily Adequate Intake for Vitamin K for Children

1. Infants up to 6 months: 2 mcg
2. Children 7-12 months: 2.5 mcg
3. Children 1-3 years: 30 mcg
4. Children 4 - 8 years: 55 mcg
5. Children 9 - 13 years: 60 mcg
6. Adolescents 14 - 18 years: 75 mcg

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Adequate Daily Intake for Vitamin K for Adults

1. Men 19 years and older: 120 mcg
2. Women 19 years and older: 90 mcg
3. Pregnant and lactating women 14-18 years: 75 mcg
4. Pregnant and lactating women 19 years and older: 90 mcg

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Interaction with medicinal products

Phenytoin (Dilantin)

Phenytoin interferes with the body's ability to use vitamin K. Taking anticonvulsants (such as phenytoin) during pregnancy or while breastfeeding may result in low vitamin K levels in newborns.

Warfarin (Coumadin)

Vitamin K blocks the effects of blood-thinning medications such as warfarin. You should not take vitamin K or eat foods containing large amounts of vitamin K while taking warfarin.

Orlistat (Xenical, Alli) and Olestra

Orlistat, a drug used for weight loss, and olestra are substances added to some foods that can reduce the amount of fat a person can absorb. Because vitamin K is a fat-soluble vitamin, these drugs can also lower vitamin K levels.

Cholesterol-lowering medications

Bile acid, used to lower cholesterol, reduces the amount of fat the body can absorb and may also reduce the absorption of fat-soluble vitamins. If you take one of these medications, your doctor may recommend vitamin K:

• Cholestyramine (Questran)
• Colestipol (Colestid)
• Colsevelam (Welchol)

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Precautionary measures

At recommended doses, vitamin K has few side effects.

Vitamin K crosses the placenta and is also found in breast milk. Pregnant and breastfeeding women should consult a physician before taking vitamin K or its supplements.

People with a rare metabolic condition called glucose-6-phosphate dehydrogenase (G6PD) deficiency should avoid vitamin K deficiency.

People who take warfarin (Coumadin) should not take vitamin K.

Antibiotics, especially those known as cephalosporins, reduce the absorption of vitamin K in the body. They can cause low vitamin K levels for more than 10 days because these drugs kill not only harmful bacteria but also the bacteria that create vitamin K.

Talk to your doctor before taking vitamin K or giving it to a child.