Which vitamin is routinely given to newborns?

• A. Vitamin A
• B. Vitamin K
• C. Vitamin D
• D. Vitamin E

Answer: (B)

Newborns are routinely given vitamin K to prevent hemorrhagic disease caused by vitamin K deficiency. At birth, vitamin K stores are very low, placental transfer is limited, and the newborn gut is sterile, so bacteria that synthesize vitamin K aren’t yet established. Breast milk also provides little vitamin K. Without adequate vitamin K, the liver cannot properly activate clotting factors II, VII, IX, and X (and proteins C and S), leading to serious bleeding, including intracranial hemorrhage. A single intramuscular dose of vitamin K1 given soon after birth effectively prevents this condition. Other vitamins aren’t routinely given at birth for this purpose (for example, vitamin D supplementation is common but aimed at preventing deficiency/rickets over time, not immediate hemorrhagic risk).