Vitamin K for Newborns: Why It Matters

According to current clinical guidelines, newborns need a vitamin K shot to prevent a life-threatening condition known as vitamin K deficiency bleeding (VKDB). VKDB is a blood-clotting disorder in infants caused by a lack of vitamin K. It may present as bruising or bleeding from the umbilical cord, nose, or intestines.

What Does Vitamin K Do in the Body?

Vitamin K plays an important role in blood clotting. It is needed to activate four key clotting factors in the liver: II, VII, IX, and X.

Without enough vitamin K, the blood loses its ability to clot, which can lead to uncontrolled bleeding.

Why Are Newborns at Risk?

There are three main reasons why infants cannot maintain adequate vitamin K levels immediately after birth:

• Limited placental transfer: Vitamin K does not pass easily from mother to baby through the placenta during pregnancy, so newborns have very small stores of the vitamin.
• Sterile gut: In adults and older children, much of the body's vitamin K is produced by beneficial bacteria in the gut. A newborn's gut microbiome is only beginning to develop and cannot yet produce enough of the vitamin.
• Low levels in breast milk.

Vitamin K Deficiency Bleeding: Types and Risks

Vitamin K deficiency can become apparent at different times, and the severity and prognosis depend on when it occurs:

• Early-onset VKDB: occurs within the first 24 hours of life.
• Classical VKDB: occurs between 2 and 7 days of life.
• Late-onset VKDB: the most insidious form, developing between 1 week and 6 months of age (most commonly between 2 and 8 weeks).

Prevention

Method of administration: an intramuscular injection (a shot in the thigh) is the gold standard for prevention.

Studies show that a single intramuscular injection provides reliable protection against all forms of VKDB, including late-onset VKDB.

Vitamin K is always administered with the mother's consent.