When mothers decide not to breast-feed, it is essential that baby receive the proper nutrition during the first year of life. Infant formulas provide an alternative that offers balanced nutrition patterned after breast milk. Most infant formulas use cow's milk as their protein source, with added fat, carbohydrates, vitamins and minerals in a formula that mimics human milk as closely as possible. There is very little nutritional difference among the leading brands, such as Enfamil and Similac, and they all contain iron, a very important mineral for infants. In fact, the American Academy of Pediatrics recommends that iron-fortified formula be fed to any baby weaned before 12 months of age.
Some infants develop excess gas or diarrhea while on formula.
Some of those babies have a milk protein allergy, meaning they have difficulty digesting cow's milk protein. These babies should be switched to a soy-protein formula such as Nursoy, Prosobee or Isomil. Specialized formulas are also available, such as formulations designed for infants and children with lactose intolerance and for firming loose, watery stools in infants older than six months. There are also specific formulas for premature babies. Babies born with metabolic diseases require severely restricted diets.