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What is Vitamin K, and why is it important for my newborn baby?

February 12, 2014

Vitamin K is a fat-soluble vitamin that our body needs to help make proteins that are needed for blood coagulation. In other words, it’s one of the ways our body works to stop bleeding. We can find vitamin K in green leafy vegetables such as spinach, kale, broccoli, and collard greens. Bacteria in our intestine also produce vitamin K. If we do not have enough vitamin K, we may experience prolonged bleeding from small cuts or big bruises from relatively small injuries.

Newborn babies are born with a very little amount of vitamin K in their bodies, so there is a small but potential risk (0.25% - 1.7% chance) of a newly born baby developing spontaneous bleeding because of vitamin K deficiency. The bleeding may occur in the brain, and the baby could have severe brain injury and damage. We can help prevent this by giving newborn babies an injection of vitamin K shortly after birth. This practice has proven to be very effective, and the American Academy Pediatrics (AAP) has supported this practice since 1961.

So what is the controversy surrounding the Vitamin K injection at birth?

In the early 1990s, there were a few studies that attempted to show an association between the vitamin K injection received at birth and an increased chance of developing childhood leukemia. These studies have been questioned and examined by two large retrospective studies in the United States and Sweden that reviewed the incidence of childhood leukemia from the National Registry of Childhood Tumors and the intramuscular administration of vitamin K during the same time frame. When comparing the data, there is no correlation between increased use of vitamin K injections and the development of childhood leukemia.

Some parents may be concerned about giving an injection to their baby shortly after birth, since the act of simply being born is already a traumatic experience for a baby. Parents may ask about giving vitamin K as an oral medication, instead of an injection. Oral vitamin K will help prevent early vitamin K deficiency bleeding in the first two weeks of life, but it does not protect well against bleeding that may occur between 2 to 12 weeks of life. It takes at least 3 months for a baby’s body to build up enough proteins and vitamin K to help prevent bleeding, so that is why the injection of vitamin K shortly after birth is so important.

Vitamin K administration is also very important in babies that are exclusively breast-fed, because breast milk has a lower concentration of vitamin K. If a baby is exclusively breast-fed and did not receive the vitamin K injection at birth, the chance of developing vitamin K deficiency after 2 weeks of age is about 1 in 15,000. Although the chance is small, when it does occur the results can be devastating. About half of these babies will have bleeding in their brain that leads to permanent brain damage.

The American Academy Pediatrics recently released a statement about where we as pediatricians stand in regards to the administration of Vitamin K to newborn babies. The AAP recommends:

  1. Vitamin K should be given to all newborn infants as a single, intramuscular dose of 0.5 to 1mg.
  2. Additional research should be conducted on the efficacy, safety, and bioavailability of vitamin K to prevent late vitamin K deficiency bleeding.
  3. Health care professionals should promote awareness among families of the risks of late vitamin K deficiency bleeding associated with inadequate vitamin K prophylaxis from current oral dosage regimens, particularly for newborns who are breast-fed exclusively.