Vitamin K is a group of fat-soluble vitamins that are structurally similar and play an important role in the regulation of blood coagulation, necessary for supporting blood clotting. Vitamin K also supports bone metabolism and calcium metabolism in the vascular system.

According to recent studies, 90% of children with cerebral hemorrhage usually occur at 30 – 40 days of age, the cause of which is vitamin K deficiency. If not detected and treated promptly, it will endanger the child’s life.

Causes of vitamin K deficiency in children

There are 2 types of natural vitamin K

• Vitamin K1 : Found in many green vegetables (cabbage, broccoli …), vegetable oils (soybean oil), fruits (avocado, kiwi, grapes …). However, only 5 – 10% of vitamin K1 is absorbed in the digestive tract from food sources. Vitamin K1 plays a role in activating blood clotting factors in the liver.
• Vitamin K2 : Produced by beneficial bacteria in the intestine. Enhances the function of vascular endothelial cells, prevents atherosclerosis, prevents vascular occlusion, prevents myocardial infarction, angina.

There are many causes of vitamin K deficiency in young children, including a lack of vitamin K in the diet. Newborns do not have enough vitamin K reserves, because the amount of vitamin K transferred from the mother through the placenta to the fetus is very small, the amount of vitamin K in breast milk is only 2 – 15 micrograms/liter. Breastfed children, especially premature babies, have a higher rate of bleeding due to vitamin K deficiency. Children who are breastfed by people who eat a restricted diet are also susceptible to vitamin K deficiency, an unreasonable diet lacking in nutrients rich in vitamin K is also a cause.

Vitamin K is synthesized from intestinal bacteria, infants with insufficient intestinal bacteria and young children using many broad-spectrum antibiotics are also one of the causes of endogenous vitamin K deficiency.

Vitamin K is absorbed in the intestine, malabsorption conditions, prolonged diarrhea, biliary obstruction, pancreatic cystic fibrosis, gastrointestinal bleeding… all reduce vitamin K absorption.

Mothers taking some drugs with anticoagulant and anticonvulsant effects such as phenytoin, primidone, phenobarbital can cause hypoprotheomninemia and decreased coagulation factors VII, IX, and X in the plasma of newborns.

Vitamin K deficiency, if not detected and treated promptly, will endanger the child’s life.

What are the consequences of vitamin K deficiency in children?

According to research, up to 90% of children with cerebral hemorrhage due to vitamin K deficiency usually occur at 30 – 40 days of age, and the cause is vitamin K deficiency. Children with cerebral hemorrhage, despite active treatment, still have a high mortality rate or sequelae (mortality rate is 25 – 40%, sequelae are 40 – 50%). The most common sequelae include: Cerebral atrophy, hydrocephalus, microcephaly, epilepsy, cerebral palsy or psychomotor developmental disabilities.

About 50% of newborns at 5 days of age have vitamin K deficiency as detected by prolonged prothrombin time testing.

Depending on the cause of vitamin K deficiency, it can lead to different clinical manifestations such as:

• Early hemorrhagic disease in newborns (0 – 24 hours old): Pulmonary hemorrhage, intracranial hemorrhage, gastrointestinal bleeding.
• Classic neonatal hemorrhage (1 – 7 days old): Gastrointestinal bleeding, subcutaneous bleeding…
• Late hemorrhage (in infants 7 days – 3 months, classical is 30 – 45 days, can be later up to 12 months); Intracranial hemorrhage, subcutaneous hemorrhage, gastrointestinal bleeding…

Diagnosis and treatment of vitamin K deficiency

If the child has clinical manifestations such as: The newborn may refuse to breastfeed, be lethargic or irritable, cry loudly, have convulsions, may have subcutaneous bleeding, umbilical bleeding, pale skin, bulging fontanelle… Doctors will order a blood clotting test. From there, the diagnosis of vitamin K deficiency will be determined.

Depending on each case, doctors will prescribe appropriate treatment, including vitamin K injections in cases where the child has simple vitamin K deficiency.

Transfusion of fresh frozen plasma in severe cases or children requiring surgery with coagulation disorders due to vitamin K deficiency.

Advice for parents

To prevent vitamin K deficiency in children, during pregnancy and breastfeeding, mothers should eat a full diet: Meat, fish, shrimp, crab, snails, frogs, fruits, green vegetables of all kinds… Children in the weaning period also need a balanced diet rich in vitamin K.

In summary: Hemorrhagic disease due to vitamin K deficiency is common in newborns and can cause serious consequences such as cerebral hemorrhage. Children with cerebral hemorrhage, despite active treatment, still have a high mortality rate or sequelae (mortality rate is 25 – 40%, sequelae are 40 – 50%). Therefore, immediately after birth, infants are often given prophylaxis for neonatal cerebral hemorrhage in accordance with the National Guidelines on Reproductive Health Care Services issued in Decision No. 4128/QD-BYT dated July 29, 2016 of the Ministry of Health.

The recommended best practice is that all newborns receive a routine intramuscular dose of vitamin K within the first 6 hours after birth with the following dosage:

• For infants > 1,500 grams: Intramuscular injection of 1 mg of vitamin K1.
• For infants ≤ 1,500 grams: Intramuscular injection of 0.5 mg of vitamin K1.

During the process of raising and caring for the child, if the child shows signs of suspected vitamin K deficiency, the family should not arbitrarily supplement the child with vitamin K, but should immediately take the child to a specialized hospital for timely diagnosis and treatment.