MODEL RELEASED. Vitamin K injection. One month old baby girl receiving by mouth (oral) a dose of vitamin K. The vitamin K is injected into the baby's mouth by a health worker's hand using a needle-less syringe. Vitamin K is essential for blood clotting. Bacteria which live in the intestines manufacture vitamin K. Babies lack this bacteria, so vitamin K supplements are routinely administered soon after birth. It is safer to administer the vitamin K by mouth. Other sources of vitamin K include green leafy vegetables such as cabbage, broccoli and turnip greens.