Now that my son is two I was trying to figure out whether or not he needs a vitamin supplement. Dr. Sears suggests the following….
Unless their doctor determines otherwise, exclusively breastfed term infants do not need extra vitamins. Human milk contains all of the essential vitamins. As long as your infant is getting enough milk, he or she is getting enough vitamins. Commercial formulas also contain all the essential vitamins, providing your infant consumes the entire can of formula each day. If your infant averages thirty-two ounces of formula (one liter) a day, extra vitamins are unnecessary unless he needs extra nutrition – for prematurity, for example. If and when your infant drinks less than this amount of formula each day, supplemental vitamins are advised depending on the consistent intake of solid foods.
Because of the erratic diets of most toddlers, pediatricians usually recommend supplemental A,D, and C vitamins, sometimes adding the B team. Vitamin supplements should be continued until your child eats a consistently- balanced diet. (For more information, see Vitamins under Family Nutrition.)