About Vitamin K Deficiency Bleeding

What it is

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.

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 have bleeding into their intestines, or into their 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.

Types

Healthcare providers divide VKDB into three types, based on the age of the baby when the bleeding problems start: early, classical and late.

• 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⁾

The chart below helps explain these three different types.

Signs and symptoms

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 babies with a darker complexion, the gums may appear pale.
• The white parts of your baby’s eyes look yellow after the first 3 weeks of life.
• 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 (possible signs of bleeding in the brain).

Risk factors

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 begin making vitamin K. The reasons for this include the following:

• 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 breast milk alone.

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, because breast milk contains only small amounts of vitamin K.
• 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.

Prevention

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. 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 FAQs.