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Vitamin K Deficiency

Written by Ada’s Medical Knowledge Team

Updated on

What is vitamin K deficiency?

Vitamin K is an essential fat-soluble vitamin which is important to bone and heart health, as well as blood clotting and brain function. A deficiency of vitamin K is rare in healthy adults due to its presence in a variety of common dietary sources, including green leafy vegetables, oils and grains.

While newborn babies are particularly at risk, people of any age can develop a vitamin K deficiency, which may be triggered by a number of factors, including liver disease, malnutrition and as a consequence of taking certain prescription drugs. 1

Vitamin K deficiency is quite rare in infants today, because vitamin K prophylaxis is routinely given to babies at birth in many parts of the world. The deficiency is more common in infants who are completely breastfed, as baby milk formula generally contains supplementary vitamin K. 2

The main symptoms of a vitamin K deficiency include bruising easily and excess bleeding.

A nutritionally balanced diet is normally sufficient to prevent vitamin K deficiency. If a deficiency of vitamin K does develop, it can usually be treated effectively if detected early.

Vitamin K deficiency symptoms

Signs and symptoms of a vitamin K deficiency include: 2 3

  • Excessive bleeding, e.g. from a cut, wound, injection or puncture
  • Easy bruising
  • Heavy menstrual bleeding

If you think that you or a loved one might have signs of vitamin K deficiency, try using the Ada app to find out more about your symptoms.

Symptoms of vitamin K deficiency in infants

Infants are at an increased risk of developing a vitamin K deficiency until they begin to eat regular foods, which will usually be around four to six months after birth.

Signs and symptoms that could indicate vitamin K deficiency in babies include: 4 5 6 7 8

  • Bruising, especially around the head or face
  • Bleeding episodes, e.g. around the belly button, nose and mouth, penis if circumcised and at vaccination sites
  • Paleness, which may be noticeable in the gums of darker-skinned infants
  • Yellowing of the skin and eyes, occurring three or more weeks after birth, distinct from newborn jaundice, which typically clears by the time the baby is two weeks old 9
  • Stool that is bloody, dark or sticky like tar
  • Blood in the urine or vomit
  • Irritability
  • Excessive tiredness or sleepiness

Good to know: If any of these signs and symptoms occur or there is any suspicion of a vitamin K deficiency, urgent medical attention should be sought.

Vitamin K deficiency bleeding (VKDB)

Infants with a vitamin K deficiency are susceptible to vitamin K deficiency bleeding (VKDB), also known as hemorrhagic disease of the newborn, a rare condition which stems from the blood being unable to clot. 5

The bleeding can occur anywhere in the body, including internally, for example in the gastrointestinal tract, and brain. Bleeding into the brain is particularly common with late-onset VKDB.

If bleeding is internal, it can be extremely difficult to notice and may lead to serious complications and even death. Signs are not always obvious and may be mistaken for other conditions. 4 6

VKDB is classified as one of three types according to when it develops: 5 10

  • Early-onset VKDB, which develops within 24 hours of the infant being born
  • Classic-onset VKDB, which develops within 2-7 days of the infant being born
  • Late-onset VKDB, which develops between two weeks and six months after birth, most commonly in babies who have not been given a vitamin K shot

In addition to the symptoms listed above, signs of VKDB in babies may include: 4 5 6 7 8

  • Poor feeding
  • Low weight or difficulty gaining weight

Good to know: Brain bleeds may cause seizures and frequent vomiting in a baby. There may also be a lump on the head that was not there before.

If any unusual symptoms are present or vitamin K deficiency is suspected, a medical professional should be contacted immediately.

To help prevent VKDB and other potential complications of low vitamin K levels, vitamin K is routinely given by injection or orally to all infants at birth, in many parts of the world.

Risk factors for VKDB

Factors that increase an infant’s chances of developing VKDB include: 11

  • Breastfeeding. Children who are exclusively breastfed are roughly 20 times more likely to experience VKDB. This is due to the low levels of vitamin K in breast milk compared to formula milk, as well as the low levels of bacteria that help the body synthesize vitamin K. However, breastfeeding has many other benefits, and concern about vitamin K deficiency is no reason not to do it, as the routine administration of vitamin K to newborns significantly reduces the risk of VKDB.
  • Pharmaceuticals. Certain medication taken by the mother can increase the chances of an infant developing VKDB. These include rifampicin, isoniazid, anticoagulants and anticonvulsant agents.
  • Warm environments. Extended exposure to a warm environment can make late-developing VKDB more likely. Late-developing VKDB usually peaks at around 3-8 weeks.
  • Liver disease. There is increased risk if an infant has an unsuspected liver disease, especially alpha-1-antitrypsin deficiency.
  • Malabsorption. An inability to absorb vitamins due to factors and conditions such as cystic fibrosis, celiac disease and long-lasting diarrhea.

Prevention and treatment of VKDB in infants

A vitamin K supplement should be given to the infant as soon as VKDB is suspected. In severe cases, fresh frozen plasma, a blood product containing coagulating properties, may also be administered. If an infant has lost a large amount of blood, a blood transfusion may also be necessary.

To help prevent VKDB from occurring, a vitamin K supplement in the form of phytonadione is routinely given, with parental permission, to infants after birth in many parts of the world, including the United States and United Kingdom. It is sometimes called “the vitamin K shot”, but may be administered orally. The procedure is considered safe by healthcare professionals. 1 4 12 13 14

Vitamin K deficiency causes and risk factors&Risk factors

A vitamin K deficiency can occur in people of any age, but newborn infants are particularly at risk. Vitamin K deficiency is most likely to result from a lack of vitamin K reaching the fetus before birth and the lack of vitamin K in breast milk.

Other risk factors for a vitamin K deficiency include: 1 15

  • Liver disease
  • Conditions that affect the body’s ability to absorb vitamin K, such as celiac disease, Crohn’s disease and tropical sprue
  • Biliary tract disease
  • Malnutrition
  • Certain drugs, such as coumarin anticoagulants, cholestyramine, salicylates, rifampin and barbiturates

It should be emphasized that a vitamin K deficiency in healthy adults is rare due to the vitamin’s presence in a variety of food sources, notably green leafy vegetables, oils and grains.

Vitamin K deficiency diagnosis

Diagnosing a deficiency of vitamin K will typically begin with a physical examination by a doctor.

If a deficiency is suspected, the next stage of diagnosis will normally be blood tests. A blood test can reveal the level of prothrombin, a clotting agent in the blood, which will be lower than average in the case of a vitamin K deficiency.

However, as low levels of prothrombin can also be symptomatic of other conditions, the diagnosis will generally be confirmed with a vitamin K injection. If symptoms subside following the injection, the diagnosis of vitamin K deficiency can be confirmed. 16

If you think that you or a loved one might have a vitamin K deficiency, start a free symptom assessment using the Ada app.

Vitamin K deficiency prevention

Most healthy adults are able to prevent a deficiency of vitamin K by maintaining a diet containing foodstuffs which are rich in the vitamin, such as:

  • Green leafy vegetables, such as kale, chard, watercress and spinach
  • Oils, such as olive, cottonseed and soya bean
  • Grains, such as rye grain, spelt and buckwheat

In some cases, a vitamin K supplement may be recommended for those at risk of developing a vitamin K deficiency.

Vitamin K deficiency treatment

The appropriate treatment method for a vitamin K deficiency depends on the severity of the condition, particularly the severity of the associated bleeding, and its underlying cause.

If bleeding reaches life-threatening levels, fresh frozen plasma will be administered. In other cases, or after fresh frozen plasma has been administered, a vitamin K supplement will be administered to the person, usually intravenously or into the muscle. 1 17

Other terms associated with vitamin K deficiency

  • Low vitamin K
  • VKDB
  • Hemorrhagic disease of the newborn

Vitamin K deficiency FAQs

Q: What does vitamin K do?
A: Vitamin K plays an important role in keeping the bones, heart and brain healthy. It is also essential for normal blood clotting, known as coagulation; low levels of vitamin K can cause a person to bleed excessively. For this reason, it is sometimes called “the blood clotting vitamin”. 18

Q: What is the most common cause of vitamin K deficiency?
A: Vitamin K deficiency is most likely to occur in newborn infants, as a result of low levels of the vitamin being transferred from the mother to the baby during pregnancy, naturally low levels in breast milk, and the baby’s body experiencing difficulty making the vitamin on its own.

However, most newborns are given a vitamin K supplement after birth to avoid complications. Vitamin K deficiency is rare in adults, but can be caused by malnutrition, certain prescription medication and conditions that lead to malabsorption. For more information, see the section on causes above. 15

Q: Why is vitamin K deficiency rare in adults?
A: Low levels of vitamin K are rare in healthy adults because it is easy to obtain sufficient quantities of the vitamin by eating a balanced diet, and the body is able to produce some vitamin K on its own. 15

Q: What foods are high in vitamin K?
A: Examples of good sources of vitamin K include: 18

  • Green leafy vegetables like spinach, kale and lettuce
  • Other vegetables like brussels sprouts, cabbage and broccoli

Q: Does vitamin K deficiency cause bruising?
A: Vitamin K deficiency can cause a person to bruise easily. However, there may be other causes of bruising. Vitamin K deficiency can also cause heavy bleeding.

If you think that you or a loved one might have signs of vitamin K deficiency, try using the Ada app to find out more about your symptoms.

Q: Can vitamin K deficiency cause anemia?
A: Vitamin K deficiency in itself does not cause anemia. However, the heavy bleeding that can be a symptom of the deficiency, may sometimes be associated with anemia. Read more about Anemia ».

Q: Can vitamin K deficiency cause hair loss?
A: Hair loss is not a symptom of a lack of vitamin K. However, hair loss may sometimes be a symptom of anemia or a deficiency of another vitamin, such as vitamin D. Read more about Vitamin D Deficiency ».

Q: How is vitamin K deficiency treated?
A: Low levels of vitamin K in adults can often be treated with dietary changes to include more leafy green and other vegetables. Sometimes, a doctor may recommend vitamin K supplements, typically in the form of phytonadione tablets or injections. Newborn babies will usually receive a vitamin K shot to prevent deficiency. 15