Womens Clinic of Seattle

Vitamin K for the Newborn

Vitamin K is a substance which is used by the body during the clotting process to stop bleeding. It is usually produced from normal bacteria in the intestines. Newborn infants do not store Vitamin K in their bodies and do not have enough bacteria in their intestines to produce it. Therefore, all newborns have low levels of Vitamin K. Breast milk is very low in Vitamin K, whereas infant formula is supplemented with Vitamin K. Without adequate levels of Vitamin K, newborns are at risk for developing a bleeding disorder called Hemorrhagic Disease of the Newborn (HDN).

Mom and Baby Infants with HDN bruise easily and bleed excessively. Bleeding may occur in the nose, intestines, brain, or other vital organs, leading to permanent injury or death. HDN usually occurs in the first week of life but can occur up to three months of age. The incidence of HDN varies widely from one in 200-400 births to 1.7 in 100 births.

Because of the risk of HDN, the American Academy of Pediatrics recommends that all infants receive Vitamin K after birth. Traditionally, in the United States, Vitamin K has been given by one injection ("shot"). The advantages of an injection are that a high level of Vitamin K can be achieved and that HDN is virtually nonexistent in infants given an injection of Vitamin K.

Vitamin K can also be given orally (squirted into the mouth). Many doctors do not believe that the oral method is as effective as injection, due to unknown absorption in the stomach and intestines and potential vomiting of all or part of the dose. Blood levels of Vitamin K following oral administration have been shown to be significantly less than levels following IM administration, but it is unknown what level is necessary to prevent HDN. It is also unclear as to the number of oral doses required to prevent HDN.

If you have any questions regarding Vitamin K for your newborn you should discuss them with the physician who will be caring for your new baby.

Back to the Pregnancy Information web page.