Baby need a vitamin D supplement
It depends on whether you breastfeed your baby or how much vitamin D-fortified formula or cow’s milk your baby is drinking.
Consider these guidelines from the American Academy of Pediatrics for vitamin D for babies:
Breastfed or partially breastfed babies need 400 international units (IU) of liquid vitamin D a day — starting soon after birth. Babies should continue to receive this amount of vitamin D until weaned or until they drink 32 ounces (about 1 liter) a day of vitamin D-fortified formula or, after age 12 months, whole milk.
Babies getting less than 32 ounces (about 1 liter) a day of vitamin D-fortified formula need 400 IU of liquid vitamin D a day — starting in the first few days after birth. Babies should continue receiving the vitamin D supplement until they drink at least 32 ounces (about 1 liter) of vitamin D-fortified formula a day.