What is Vitamin K Deficiency Bleeding?

  • Vitamins are substances our bodies need, which we get from either the foods we eat or from a multivitamin.
  • Vitamins are normally stored in the body. A person without enough of a vitamin stored in the body is “vitamin deficient” or has a “vitamin deficiency”.

What is vitamin K and why is it important?

Vitamin K is a substance that our body needs to form clots and to stop bleeding.  We get vitamin K from the food we eat.  Some vitamin K is also made by the good bacteria that live in our intestines. Babies are born with very small amounts of vitamin K stored in their bodies, which can lead to serious bleeding problems if not supplemented.

What is Vitamin K Deficiency Bleeding or VKDB?

Vitamin K deficiency bleeding or VKDB, occurs when babies cannot stop bleeding because their blood does not have enough Vitamin K to form a clot. The bleeding can occur anywhere on the inside or outside of the body.  When the bleeding occurs inside the body, it can be difficult to notice.  Commonly, a baby with VKDB will bleed into his or her intestines, or into the brain, which can lead to brain damage and even death. Infants who do not receive the vitamin K shot at birth can develop VKDB at any time up to 6 months of age. There are three types of VKDB, based on the age of the baby when the bleeding problems start: early, classical and late. More information about these types is included below.

A newborn baby

Why are babies more likely to have vitamin K deficiency and to get VKDB?

All infants, regardless of sex, race, or ethnic background, are at higher risk for VKDB until they start eating regular foods, usually at age 4-6 months, and  until the normal intestinal bacteria start making vitamin K. This is because:

  • At birth, babies have very little vitamin K stored in their bodies because only small amounts pass to them through the placenta from their mothers.
  • The good bacteria that produce vitamin K are not yet present in the newborn’s intestines.
  • Breast milk contains low amounts of vitamin K, so exclusively breastfed babies don’t get enough vitamin K from the breast milk, alone.

What can I do to prevent my baby from getting vitamin K deficiency and VKDB?

Protect Your Baby from Bleeds Fact Sheet

The good news is that VKDB is easily prevented by giving babies a vitamin K shot into a muscle in the thigh.   One shot given just after birth will protect your baby from VKDB.  In order to provide for immediate bonding and contact between the newborn and mother, giving the vitamin K shot can be delayed up to 6 hours after birth.

Is the Vitamin K shot safe?

Yes.  Many studies have shown that vitamin K is safe when given to newborns.   For more information about the safety of the vitamin K shot, please see our FAQ’s.

What might cause babies to be deficient in vitamin K and have bleeding problems?

Some things can put infants at a higher risk for developing VKDB. Babies at greater risk include:

  • Babies who do not receive a vitamin K shot at birth.  The risk is even higher if they are exclusively breastfed.
  • Babies whose mothers used certain medications, like isoniazid or medicines to treat seizures.  These drugs  interfere with how the body uses vitamin K.
  • Babies who have liver disease; often they cannot use the vitamin K their body stores.
  • Babies who have diarrhea, celiac disease, or cystic fibrosis often have trouble absorbing vitamins, including vitamin K, from the foods they eat.

How often are babies affected with vitamin K deficiency bleeding?

Since babies can be affected until they are 6 months old, healthcare providers divide VKDB into three types; early, classical and late.   The chart below helps explain these three different types.

  • Early and classical VKDB are more common, occurring in 1 in 60 to 1 in 250 newborns, although the risk is much higher for early VKDB among those infants whose mothers used certain medications during the pregnancy.
  • Late VKDB is rarer, occurring in 1 in 14,000 to 1 in 25,000 infants (1–3).
  • Infants who do not receive a vitamin K shot at birth are 81 times more likely to develop late VKDB than infants who do receive a vitamin K shot at birth. (4)
Types of VKDB
Type of VKDB (5) When it Occurs Characteristics
Early-onset within the first 24 hours after birth
  • Severe
  • Mainly found in infants whose mothers used certain medications  (like medicines to treat seizures or isoniazid) that interfere with how the body uses vitamin K
Classical 2 days – 1 week after birth
  • Bruising
  • Bleeding from the umbilical cord
Late-onset 1 week – 6 months after birth, most commonly 2 – 8 weeks after birth
  • 30-60% of infants have bleeding within the brain
  • Tends to occur in breastfed only babies who have not received the vitamin K shot
  • Warning bleeds are rare

What things should I look for in my baby if I think he or she might have VKDB?

Unfortunately, in the majority of cases of VKDB, there are NO WARNING SIGNS before a life-threatening event starts.  Babies with VKDB might develop any of the following signs:

  • Bruises, especially around the baby’s head and face
  • Bleeding from the nose or umbilical cord
  • Skin color that is paler than before.  For darker skinned babies, the gums may appear pale
  • After the first 3 weeks of life, the white parts of your baby’s eyes may turn yellow.
  • Stool that has blood in it, is black or dark and sticky (also called ‘tarry’), or vomiting blood
  • Irritability, seizures, excessive sleepiness, or a lot of vomiting may all be signs of bleeding in the brain

Remember, VKDB is easily preventable with just a single vitamin K shot at birth.


  1. Hand I, Noble L, Abrams SA; AAP Committee on Fetus and Newborn, Section on Breastfeeding, Committee on Nutrition. Vitamin K and the Newborn Infant. Pediatrics. 2022;149(3):e2021056036
  2. Zipursky A. Prevention of vitamin K deficiency bleeding in newborns. Br J Haematol 1999;104:430–7.
  3. Sutor AH, Kries R, Cornelissen EAM, McNinch AW, Andrew M. Vitamin K deficiency bleeding (VKDB) in infancy. Thromb Haemost 1999;81:456–61.
  4. McNinch AW, Tripp JH. Haemorrhagic disease of the newborn in the British Isles: two year prospective study. BMJ 1991;303:1105–9.
  5. Hand I, Noble L, Abrams SA; AAP Committee on Fetus and Newborn, Section on Breastfeeding, Committee on Nutrition. Vitamin K and the Newborn Infant. Pediatrics. 2022;149(3):e2021056036