Question

Prophylactic dose of vitamin K given to newborn infants at delivery is?

• A. 1 mg
• B. 5 mg
• C. 10 mg
• D. 15 mg

Hint:

Every newborn gets a single small intramuscular injection right after birth.

Answer 1

The Correct Option is A

Step 1: Newborns are highly prone to vitamin K deficiency. This is because of low fetal fat stores, low levels of vitamin K in breast milk, a sterile infantile gut that cannot synthesise vitamin K, an immature liver, and poor placental transfer of the vitamin.

Step 2: Vitamin K is needed for hepatic synthesis of clotting factors II, VII, IX and X. A deficiency leads to bleeding, known as vitamin K deficiency bleeding (haemorrhagic disease of the newborn), which may present as intracranial, gastrointestinal or skin bleeding within the first week of life.

Step 3: To prevent this, a single prophylactic dose of vitamin K \(1\ mg\) is given intramuscularly to every newborn at the time of delivery. Hence the correct answer is 1 mg.

Step 4: Doses of 5 mg, 10 mg or 15 mg are far higher than required for prophylaxis and are not the standard recommended dose, so they are incorrect.