What is Vitamin K and why do we give it to babies?

What is Vitamin K?

Vitamin K is a fat-soluble vitamin found in green leafy vegetables, vegetable oils and cereal grains. Full-fat dairy products also contain a form of vitamin K.

It was discovered in the early part of the 20th century and found to have an important role in coagulation (clotting) of the blood.

It was considered such a significant development that the two scientists who first studied it were awarded the Nobel Prize for Medicine in 1943.

Why do we give Vitamin K to babies?

  • Newborn babies do not have large reserves of vitamin K, and it does not pass into the mother’s breastmilk in large quantities either, although it is added to formula milk.
  • Without sufficient vitamin K, there is a risk of developing a condition called Vitamin K deficiency bleeding. The risk is low – about one in 10,000 babies are affected – but the condition is serious as it can cause dangerous bleeding in the gut and brain.
  • The risks are slightly higher if your baby is born prematurely or is delivered by forceps, ventouse or caesarean section. Breathing difficulties and liver problems in the baby, as well as certain medications taken by the mother during pregnancy, can also increase the risk.
  • However, some babies without these risk factors still develop the condition, and therefore vitamin K is routinely given to infants soon after birth.
  • In the early 1990s, two small-scale studies suggested a possible connection between childhood leukaemia and vitamin K at birth. But several further studies found no link and in 1997 the UK’s Department of Health confirmed that giving babies vitamin K is safe.

How is it given to babies?

  • Vitamin K is commonly given as a single injection, but it can also be offered orally in three separate doses.
  • Some parents prefer the oral option to avoid the pain of an injection soon after birth, but others select the injection, preferring to avoid having to remember follow-up doses in the early weeks.
  • Ask staff to confirm that your baby has had vitamin K before leaving the hospital.
  • If you have opted for oral doses of vitamin K, your baby will need a second dose at about one week old and a third at one month. In the UK these are administered by midwives and health visitors.

Vitamin K is important for your newborn’s health. During pregnancy, your doctor or midwife should discuss vitamin K with you and help you to make the right decision for you and your baby.