Prenatal & Postpartum Articles

Choosing A Formula

By Dr. Harold Raucher


Virtually all pediatricians and experts recommend breast feeding. Breast milk is preferred because it contains ingredients nutritionally and immunologically that provide many benefits to an infant. But breast feeding isn't always possible. Some mothers can't nurse due to medical conditions or medications they take (that appear in breast milk and might be harmful to the baby). Sometimes breastfeeding just doesn't work, even after great effort. In other cases, a mother just doesn't feel comfortable nursing or doesn't enjoy breastfeeding. Breastfeeding may also not be a good option for some families due to mom's work requirements.


Formulas were created to be a replacement for breast milk. Since breast milk is the "gold standard" for infant nutrition, formula makers try to make their product similar to breast milk. The history of formulas is long, but the clear trend is that formulas have gotten closer and closer to breast milk. Formulas contain 20 calories per ounce; so does breast milk. The ratio of protein, carbohydrate, and fat is also designed to resemble breast milk. Calcium and other minerals are carefully modified to be like breast milk. Although the formulas of today cannot provide the immunologic benefits of breast milk (mother's antibodies, antibacterial compounds, white blood cells), from a nutritional standpoint they are quite good.


Understanding the differences between formulas can be confusing. But basically there are three categories of formula:

  • Cow's milk formulas
  • Soy formulas
  • "Hypoallergenic" formulas


As the name implies, cow's milk formulas start with cow's milk and then add and subtract until the final product is created. Similarly, soy formulas start with soy beans. Hypoallergenic formulas add an extra step. The cow's milk proteins (which are the cause of most milk allergies) are broken down from large molecules to tiny fragments that the infant's immune system will not recognize as coming from the original protein.


Some formulas are "low iron" (no iron added) or have added iron ("with iron"). Actually, cow's milk has nearly the same iron content as human milk. However, due to other factors in breast milk, the iron is absorbed much more completely from breast milk. In order to give the infant the equivalent amount of (absorbed) iron, extra iron must be added. Most pediatricians recommend formulas with the added iron. It is often said that the iron in formula can constipate an infant, but this does not occur in the vast majority of children.


The latest improvement in formulas is the addition of certain fatty acids, DHA and ARA. These components are found in breast milk, but not in cow's milk. Some benefit in vision and in learning ability has been seen from these fatty acids in animal studies and in short-term studies in infants.


You can rest assured that formulas are a nutritious substitute for breast milk that can be used if breast milk cannot be used.