Skip to content
Home » Vitamin K shots for newborns — it’s safe, effective, and important

Vitamin K shots for newborns — it’s safe, effective, and important

Adjacent to the anti-vaccine movement, a lot of these same people eschew vitamin K injections for their newborn children because of…reasons. And none of those reasons make sense.

The hepatitis B vaccine is usually given at the same time as the vitamin shot, so they are often lumped together within the anti-vaccine world of refusing them for their newborn babies.

Vitamin K shots are important to the health and well-being of newborn children. And there are good reasons why the vast majority, up to and including protecting the newborn’s life.

Let’s take a look at vitamin K and why it’s critical to the health of a newborn. We will also dismiss some of the myths and fabrications about the safety and effectiveness of this shot.

baby sleeping on white cotton vitamin K
Photo by Pixabay on

What is vitamin K?

Vitamin K is a family of fat-soluble vitamins that modify certain proteins which are necessary for blood coagulation. Without it, the body cannot form blood clots which will lead to bleeding and eventual death.

Vitamin K1 (is primarily from plants, especially leafy green vegetables. In addition, small amounts are provided by animal-sourced foods. Vitamin K2 comes primarily from animal-sourced foods, with poultry and eggs being much better sources than beef, pork, or fish. In addition, both of the vitamins are produced by “good” gut bacteria.

For most adults who eat a broad diet of plants and animals, there is usually no concern for a vitamin K deficiency, and they are usually not at risk of uncontrolled bleeding.

vegetable salad on top of white ceramic plate
Photo by Marianna OLE on

Why is the vitamin shot important for newborns?

All infants, regardless of sex, race, or ethnic background, are at higher risk for vitamin K deficiency bleeding (VKDB) until they start eating regular foods (as discussed above), 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 little of the vitamin stored in their bodies because only small amounts pass to them through the placenta from their mothers. Vitamin K refuses often think that the mother passes along sufficient vitamin K to the fetus.
  • The good bacteria that produce the vitamin 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.

VKDB is a serious condition. 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.

There are no signs of VKDB. There is no prediction if or when it might happen. That is why the shot is strongly recommended for newborns.

According to the CDC, early VKDB is more common, occurring in 1 in 60 to 1 in 250 newborns. However, the risk is much higher for early VKDB among those infants whose mothers used certain medications during the pregnancy. For infants who receive the shot soon after birth, the risk of VKDB is lower than 1 in 1000. Moreover, one in five babies die of VKDB.

smiling baby biting right index finger vitamin K
Photo by Vika Glitter on

Safety of vitamin K shot

This vitamin injection is extremely safe. The injection has been recommended by the American Academy of Pediatrics since 1961. Furthermore, according to the CDC, there has been precisely one case reported over 60 years of an allergic reaction to the shot in a newborn infant.

Vitamin K refusers like to point to a black box warning on the injection. A black box warning is an important part of a medical product’s package insert — it means that the healthcare professional who is giving the drug must not ignore the warning. This sounds serious to most people. However, in this case, the black box warning for the shot is not for the vitamin itself, but for the synthetic preservative benzyl alcohol that may be present in some formulations of the injection. The warning advises against using products with benzyl alcohol in premature infants.

The black box warning is for a specific use, premature infants, not for the vast majority of newborn babies. Furthermore, there are vitamin K shots that do not contain benzyl alcohol and are safe for premature infants.

Some refusers like to claim that the injection contains phytonadione, “a synthetic (lab-made) chemical” that is not natural. However, phytonadione is vitamin K, it’s just the man-made version. It is chemically and biologically identical to the naturally occurring sources of the vitamin. Almost ALL vitamins sold in drug and health stores are man-made versions.

Other refusers like to claim that the injection causes jaundice. A Texas Children’s Hospital blog post dedicated to dispelling myths about the vitamin injection says: “Jaundice associated with vitamin K has been observed only in high-risk babies (such as premature babies) in doses 30-60 times higher than the dose we give.”

Finally, as I wrote above, breastfeeding the baby is not going to prevent VKDB. Even mothers who supplement with the vitamin are still not going to be able to provide sufficient vitamin K to their newborns.


Vitamin K refusal is so adjacent to the anti-vaccine movement I sometimes consider the shot to just be a vaccine. The refusers use some of the same unfortunate and ill-founded arguments as anti-vaxxers, all to the detriment of the health and well-being of newborn infants.

The shot is safe. The shot prevents bleeding. The shot saves lives. But then again, it’s the same with vaccines.

Michael Simpson

Don’t miss each new article!

We don’t spam! Read our privacy policy for more info.

Liked it? Take a second to support Michael Simpson on Patreon!
Become a patron at Patreon!