What is a vitamin K shot?

When your baby is born, you will be offered a vitamin K injection for your newborn. This is designed to help your baby’s blood to clot.

Vitamin K is the name given to a group of vitamins which play an important role in blood clotting, regulating calcium levels in blood and bone formation. It is found in green leafy vegetables and oils like olive oil but when your baby is born, they will only have very small amounts of vitamin K in their body.

Unlike other vitamins, very little vitamin K will pass through your placenta to reach your baby. In time, your baby will start to produce their own vitamin K, using bacteria in their intestines, but in the first few days and weeks of life, they need a supplement to build up their natural stores.

A vitamin K injection is offered to newborns in the UK to reduce the risk of babies being affected by a rare but serious health condition known as vitamin K deficiency bleeding (VKDB). If a baby has VKDB, they may experience severe bleeding and there will not be high enough levels of vitamin K in their body for the blood to clot.

Although VKDB was always fairly unusual, routinely giving newborn babies a vitamin K shot at birth has drastically reduced the number of infants who are affected by it. VKDB is also known as haemorrhagic disease of the newborn.

If you choose for your baby to be given vitamin K at birth, their risk of developing VKDB falls to 1 in 100,000, according to the Department of Health.

How is the injection given?

Shortly after your baby is born, they will be given vitamin K through an injection into their thigh. The injection will go into the muscle and while it may be momentarily painful and your baby is likely to cry, this will pass very quickly.

It is very rare for an infection to develop where the injection has been given but your baby may experience a small amount of bleeding and need a plaster. There may also be a small amount of bruising in the area.

Does my baby have to have a vitamin K injection?

As with all medical tests and procedures, the vitamin K injection is optional. Your midwife should have discussed it with you during your pregnancy to give the opportunity to make an informed choice on whether you want it to be given to your baby.

Although the vitamin K injection is highly recommended, you can choose for your baby not to have it.

Is there another way my baby can be given vitamin K?

If you want your baby to be given a vitamin K supplement after birth but you are not happy for them to have the injection, you can ask for it to be given by mouth. The most common oral supplement of vitamin K is known as Konakion.

Unlike the vitamin K shot which only needs to be given once, your baby will need two or three doses. If you have decided to give your newborn formula, you will need to give your baby two doses in their first week of life.

However, if you are breastfeeding, your baby will need to be given a third dose when they are a month old. This is because formula milk is fortified with vitamin K whereas breast milk only contains low levels.

If you want your baby to be given an oral dose of vitamin K instead of an injection, make sure the team caring for you are aware. Your midwife will give the first 2mg of vitamin K as an oral drop shortly after birth. 

Another 2mg will then be given when your baby is between four and seven days old. The third dose which is given to exclusively breastfed babies is also 2mg.

The oral supplements of vitamin K taste quite bitter and your baby may try to spit it out. If they do, or they are sick within three hours, another dose may have to be given.

As vitamin K injections deliver the vitamin straight into the muscle, the shot is considered to be more efficient than the oral supplement. Babies who are premature or who need neonatal care will need to have the vitamin K injection rather than the oral drops but speak to your midwife if you have any concerns.