Ask SciMoms: Should my baby get the Vitamin K shot at birth?

One of the very first injections a newborn receives is a vitamin K shot. This potentially life-saving medication has been recommended for several decades to reduce the risk of vitamin K deficiency bleeding (VKDB). Vitamin K is a vitamin and the vitamin K shot is a “prophylactic” or  preventative treatment. This shot does not elicit an immune response, therefore, it is not a vaccine. However, the wave of misinformation surrounding vaccines has swept the vitamin K shot into its sea, and a growing number of parents are now rejecting this treatment. In this post, we’ll review the importance of the vitamin K shot, why it’s given so soon after birth, and the efficacy of alternatives to the shot.

What is Vitamin K?

Vitamin K refers to a group of vitamins that are used by our bodies for blood clotting and bone formations. Most people get sufficient vitamin K from their diet, and bacteria in our gut also generate a form of this vitamin. Because we can easily get enough vitamin K in our diets, its deficiency in adults is very rare. Vitamin K deficiency in adults is generally limited to individuals who take anticoagulants or specific antibiotics, individuals who have liver or kidney damage, or individuals with various genetic conditions where vitamin K absorption is impaired. 

Infants with vitamin K deficiency face deadly risks

Newborns are at increased risk for vitamin K deficiency because breast milk is very low in vitamin K and because their gut does not yet contain the bacteria that produce vitamin K. Additionally, vitamin K does not cross the placenta effectively and is not present in cord blood. Although formula is enriched with vitamin K, it does not have enough of this vitamin to prevent the catastrophic conditions that can develop from a deficiency, like Vitamin K Deficiency Bleeding (VKDB).

VKDB is a devastating disease that occurs when babies cannot stop bleeding because do not have enough vitamin K to form blood clots. Blood clots are needed for the healing of common injuries during birth, such as bruises or the umbilical cord stump. In severe cases, bleeding can begin spontaneously under the tissue or in critical organs. For these infants, the condition can lead to internal bleeding in various organs, including the brain, which can lead to permanent brain damage. 

There are three types of VKDB: early (0-24hrs after birth), classic (1-7 days after birth), or late onset (2-12 weeks after birth). Since it can develop days or even hours after birth, medical organizations recommend vitamin K for infants no later than 6 hours after delivery. The most effective way of giving vitamin K to newborn infants is in the form of an intramuscular injection.

Why is vitamin K delivered as an injection?

Due to the urgency in which vitamin K needs to be delivered to a newborn’s system, doctors administer a shot of vitamin K directly by intramuscular injection. Although oral delivery of vitamin K has been touted as an alternative, data indicate that this is not as effective, even when given in repeated doses. 

The evidence supporting the efficacy of the vitamin K shot is quite clear: it significantly reduces the risk of VKDB and prevents death in newborns. The CDC highlights that infants who do not receive a vitamin K shot are 81 times more likely to develop late VKDB. The incidence of early VKDB can be as high as 1 in 60 births, particularly when mothers are using specific medications during pregnancy, such as anti-seizure medication. Since the implementation of the vitamin K prophylaxis, many doctors haven’t seen even a single case of VKDB. 

SciMoms Infographic on Vitamin K

What is the risk of a vitamin K shot at birth?

Since 1961, The American Academy of Pediatrics has recommended an intramuscular injection of vitamin K for all infants. The recommended dosage has been fixed since then to decrease the risk of overdosing. There are no known side-effects, other than soreness at the injection spot and pain at the moment of delivery. These minor, short-term effects can cause anxiety for parents who want to prevent any additional pain to their children, but are minimal compared to the risk and pain that infants would suffer if they developed VKDB. 

Why not give vitamin K only to children who are at risk? 

Some parents want to “wait and see” if their children actually need vitamin K. But for most infants, there is no pre-screen or diagnostic test than can help parents determine if their children will need a vitamin K shot. All infants are at increased risk for vitamin K deficiency and VKDB. An injection of vitamin K at birth can help prevent disease and comes with almost no risks or side-effects. There’s no reason to delay this life saving shot, and every reason to get it on time.


CDC: Vitamin K and Vitamin K Deficiency Bleeding