MODEL RELEASED. Baby's vitamins. Syringe (without a needle) being used to deliver a measured oral dose of vitamin K solution to a 5-week-old baby. Vitamin K is a standard vitamin supplement for babies. It is administered to protect against bleeding disorders where internal bleeding can swiftly kill. It is usually administered in a series of oral doses, as a single dose is less effective. Generally, two doses of 1-2 milligrams (mg) of vitamin K are given in the first week of life, followed by a third dose at around one month of age if the baby is being breastfed. Cow's milk contains higher levels of vitamin K, so bottle-fed babies do not require the third dose.