Vitamin K Shot At Birth: Importance, Safety And Side Effects

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The American Academy of Pediatrics (AAP) advises administering a vitamin K shot at birth to newborns. Vitamin K is a vital fat-soluble vitamin crucial in maintaining various physiological functions, including blood clotting. The body stores the vitamin in the liver, brain, heart, pancreas, and bones, but these reserves are limited in newborns. Therefore, they are at an increased risk of vitamin K deficiency bleeding (VKDB), a rare but serious blood disorder that most often affects babies in the first days or weeks of life (1) (2) (3).

Keep reading to learn more about the safety, significance, and possible side effects of the vitamin K shot for infants.

In This Article

Why Is Vitamin K Necessary For Newborn Babies?

Vitamin K deficiency increases the risk of bleeding

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Newborns are at risk of developing a bleeding disorder called vitamin K deficiency bleeding (VKDB) due to their low stores of vitamin K at birth. This condition can lead to excessive bleeding or hemorrhage in the intestines and brain, which can cause brain damage and may even be life-threatening. Thus, babies must receive a vitamin k shot at birth to prevent VKDB. Infants who do not receive the shot may be affected by the condition up to six months of age (2) (4).

Vitamin K deficiency bleeding is generally grouped into three categories (5) (6).

Immediate-onset:It is very rare and manifests within the first 48 hours after birth. It is usually a result of some medications taken by mothers, such as anti-tubercular or anti-epileptic medicines during pregnancy.
Early-onset (formerly called classic-onset): It is also rare but most common among the three. It occurs between one to 14 days after birth and is mostly seen in breastfed infants who did not receive a vitamin K shot at birth.
Late-onset VKDB: It may occur between two weeks and six months after birth. Infants who have not received vitamin K prophylaxis are more susceptible.

Quick fact

Newborns who do not receive the vitamin K shot are about 81 times more likely to develop severe bleeding than those who do (4).

Why Do Infants Have Low Levels Of Vitamin K?

Breast milk does not supply much vitamin K to the infant

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Infants have low levels of vitamin K at birth for a few reasons (1) (7).

Babies do not develop sufficient vitamin K reserves in their bodies while in the womb as the vitamin does not move freely across the placenta from the mother to the fetus.
Newborns do not have sufficient stores of vitamin K in their livers.
The adult gut contains certain bacteria that help synthesize vitamin K in the large intestine. However, these bacteria are absent in neonates.
Breast milk does not supply much vitamin K to the infant.
Vitamin K deficiency may occur in babies born to mothers taking certain medications during pregnancy. These medications include anti-tubercularⁱXDrugs used to treat tuberculosis (TB) drugs (isoniazid, rifampicin), antiseizureⁱXDrugs/techniques used to treat epilepsy (phenytoin, barbiturates, and carbamazepine), antibiotics (cephalosporins), or vitamin K antagonists (warfarin).

Things to know

Congenital disorders such as cystic fibrosis or biliary atresia may cause newborns to develop vitamin K deficiency (1).

Can All Newborns Have Vitamin K Shots?

The Centers for Disease Control and Prevention, USA (CDC) recommends that all babies receive a vitamin K shot immediately after birth. It is because all newborns have low vitamin K levels and are at risk of bleeding (2). However, premature babies may require a lower dose that will be decided by the doctor (8).

How Is Vitamin K Given To Babies?

Newborn receives a one-time shot of vitamin K

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A one-time shot of one milligram of vitamin K is usually given after the first hour of birth. The vitamin K shot is given intramuscularlyⁱXA method of administering a drug/vaccine into the muscle tissue (IM) in your baby’s thigh within six hours of birth (9). The infant should be in skin-to-skin contact with the mother, and breastfeeding should be started in the first hour (10). The shot may be delayed up to six hours to encourage immediate bonding and contact between the newborn and the mother (11).

Oral vitamin K drops are also available for babies. However, drops are not absorbed efficiently through the intestines, and a baby requires three doses. Therefore, the first dose is given at birth, followed by the second at three to five days, and the third at four weeks after birth. Additionally, oral drops are not suitable for babies if they are premature, taking antibiotics for diarrhea, or are born to mothers taking certain medications during pregnancy. Therefore the CDC recommends the injection over oral drops (8) (11).

Experts say

The AAP recommends a single IM dose of vitamin K of 0.3 to 0.5mg/kg body weight for premature babies weighing less than 1000 grams (12).

Are Vitamin K Shots Safe?

Yes, the vitamin K shot is safe. The baby’s liver stores the vitamin K from the injection, slowly releasing it over months. It maintains the body’s required amount of vitamin K until the baby starts eating solids and obtains the vitamin from food (9).

Besides vitamin K1 (Phytonadione), the other ingredients in the shot are also considered safe. They are (4) (13):

Polyoxyethylated fatty acid derivative: It is used as a solvent and emulsifierⁱXA substance that helps mix two or more immiscible liquids to keep vitamin K in a dissolved form (as vitamin K is a fat-soluble vitamin).
Dextrose: It is a simple sugar that is considered safe for newborns.
Benzyl alcohol: It acts as a preservative and is used in minute quantities to prevent bacterial contamination in the shot.
Hydrochloride: It may be present in a small amount to adjust the pH of the solution.

Note: You may find reports of toxicity for benzyl alcohol, but the amount required to cause such side effects is about 100 times higher (given daily) than the amount found in the shot.

Quick fact

The polyoxyethylated fatty acid derivative may cause allergic reactions in adults. However, as the immune system is not sensitized to allergens in newborns, they do not show such reactions (13).

Are There Any Side Effects Of Giving Vitamin K To The Baby?

Holding and breastfeeding may soothe your baby

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The side effect of the vitamin K injection is similar to that of any other shot and may include the following:

Pain, bruising, or swelling at the injection site
Skin scarring (may occur in a few cases)
Allergic reactions (very rare)

However, they are very uncommon compared to the risk of vitamin D deficiency. You may hold your baby while the shot is being administered or breastfeed them immediately after the shot to reduce their discomfort (4).

Where To Get Vitamin K Shot?

Your doctor or midwife will explain the neonatal requirement of vitamin K and its mode of administration during your prenatal visits. Then, based on your preference, your baby will get the vitamin soon after birth. If home birth is planned, discuss vitamin K prophylaxisⁱXThe process of preventing a particular disease with your midwife.

If you have opted for oral vitamin K administration, your baby will get the first dose at birth. Then, the second at the time of the newborn screening test (you may also get it from your local healthcare provider), and the third at the hospital, through your local doctor, or a healthcare worker. Ensure to follow the recommended schedule to protect your baby from VKDB (8).

When Is A Baby At A Higher Risk Of Developing VKDB?

Preterm babies, newborns with birth trauma, those requiring surgery, and babies born to mothers who have taken medications during pregnancy that interfere with vitamin K metabolism are at a higher risk of developing vitamin K deficiency and related bleeding (10).

Research finds

Some studies suggest formula-fed babies may be less likely to develop vitamin K deficiency than breastfed infants, as formula milk is usually fortified with various minerals and vitamins, including vitamin K, in the required amounts (1).

What Are The Possible Symptoms Of Vitamin K Deficiency?

Unexplained bruising of skin is a symptom of vitamin K deficiency

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Vitamin K deficiency can cause bleeding, which can occur in several body areas, including (7):

At the site of circumcision
In the belly button area
With stools due to gastrointestinal bleeding
In the lining of the nose and mouth
In places where there has been a needle insertion

Some other symptoms of vitamin K deficiency in newborns may include:

Blood in the baby’s urine
Appearance of bruises on the skin
Seizures (due to bleeding inside the skull)

When To Consult A Doctor?

Consult your healthcare provider if your baby has unexplained bleeding, seizures, or abnormal behavior (5).

Frequently Asked Questions

1. Can I increase vitamin K in my breast milk by eating different foods or taking supplements?

Breastfeeding mothers should have a healthy diet and take multivitamins as needed. However, taking a vitamin K-rich diet or supplementation may only slightly increase the vitamin K content of breast milk and may not be enough for the baby’s needs. Infants need vitamin K to compensate for their extra low reserves, start storing the vitamin in the liver for future use, and maintain proper blood and bone health (4).

2. Why do parents decline vitamin K shots for their newborns?

In 1990, a study suggested a link between vitamin K administration and childhood cancer, causing some parents to refuse the vitamin K shot for their newborns. However, subsequent studies with larger sample sizes found no association between vitamin K and leukemia or other cancer types.

Additionally, some parents may refuse vitamin K shots to avoid what seems to be a painful intervention. There are also concerns about the preservative benzyl alcohol, though there’s no evidence of its toxicity at the amount used in a vitamin K shot. Parents may also decline the shot under the influence of peers (12).

3. Does vitamin K shot cause jaundice in newborns?

Vitamin K shot does not cause jaundice in newborns. Vitamin K-associated jaundice has been observed only in high-risk babies, such as premature infants, at doses 30 to 60 times higher than in the shot (14).

Vitamin K helps in the coagulation of blood and prevents bleeding. However, newborns naturally have low levels of the vitamin, which can put them at risk of deficiency. Vitamin K deficiency at birth can lead to VKDB, a bleeding disorder that can cause adverse health issues, such as brain damage. Thus, administering vitamin K shot at birth is considered essential. The shot and all its ingredients are considered safe for newborns. Discuss your concerns and doubts about the injection with your healthcare provider during pregnancy to make the right choice for your baby.

Infographic: The Warning Signs Of VKDB

Vitamin K deficiency bleeding (VKDB) or hemorrhagic disease of the newborn (HDN) may occur without producing any warning signs. However, babies who have not received a vitamin K shot at birth may manifest certain symptoms. The infographic below provides a list of possible symptoms of VKDB that should immediately be brought to the attention of a healthcare professional.

warning signs of vitamin k deficiency bleeding in babies (infographic)

Key Pointers

Babies are born with low vitamin K reserves, which raises their risk of VKDB.
VKDB, also known as the hemorrhagic disease of the newborn, is a rare but serious blood condition that can adversely affect infants.
Breast milk can’t provide protection against VKDB.
Vitamin k shot at birth is the most effective way to prevent vitamin deficiency after birth.
Vitamin K shot is considered safe for babies and may cause only minor side effects, such as pain or swelling at the injection site.

Educate yourself on preventive measures to mitigate health risks related to low levels of Vitamin K in newborns.

References

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