Infant Formula Primer

Primer on Infant FormulaOften a little knowledge of primary care topics can help our evaluation and management of infants presenting to the ED. We have discussed some of these previously (ex, Growth, Developmental Milestones), but let us take a moment to review another important topic – Infant Formula:


Human Breast Milk is the Best:

  • Human milk is the “optimal source of nutrition” for an infant.
  • It possesses both macro and micronutrients that are necessary and beneficial.
    • Has hormones, immunoglobulins, enzymes, and live cells
  • Unlike formulas, human milk supports:
    • GI development
    • Immune health
    • Neurodevelopment
  • The WHO and AAP recommend human milk as the sole source of nutrition for the healthy term infant up to 6 months of age. [AAP, 2012]
  • But… not every infant can have its mother’s milk….
    • Mother may be unable to produce a quantity sufficient
    • Mother’s medical condition may require medications that are unsafe for the infant
    • The infant may have special nutritional demands (ex, galactosemia)


Infant Formula: Basics

  • The formulas on the market are designed to approximate human milk.
  • They provide appropriate nutrition to support normal growth and development and are well tolerated. [Corkins, 2016]
  • Manufacturing of infant formula is regulated to ensure appropriate levels of nutrients are present.
    • Nutrients from human milk are more readily absorbed.
    • Infant formula requires higher levels of nutrients than human milk.
  • Some have added ingredients to try to be more similar to human breast milk (ex, long chain fatty acids, probiotics), but all ingredients have been deemed safe.
  • All formulas are classified based on 3 features:
    • Caloric Density
    • Carbohydrate Source
    • Protein Composition
  • Infants who have had “colic” or emesis or other symptoms concerning for formula intolerance may have had tried several different formulas… rightly or wrongly.


Infant Formula: Primer

  • There are many types, but some basic bits to know: [O’Connor, 2009]
  • Cow’s Milk Formula
    • Calorie = 20 kcal/oz; Carbohydrate = Lactose; Protein = Cow’s milk
    • Good for the vast majority of infants.
    • Preterm infants often require higher caloric density (24 kcal/oz)
      • Usually transitioned to regular calorie feeds once the infant weighs >1,800 grams or is past 34 weeks gestation.
    • No brand name is superior to another.
  • Soy Formula
    • Calorie = 20 kcal/oz; Carbohydrate = Corn-based; Protein = Soy
    • Limited indication for its use. [O’Connor, 2009]
    • Used for patients with galactosemia or congenital lactase deficiency.
    • Not actually recommended for true milk-protein allergy.
      • Patients with milk-protein allergy will often also be sensitive to soy.
  • Lactose-free Formula
    • Calorie = 20 kcal/oz; Carbohydrate = Corn-based; Protein = Cow’s milk
    • Examples: Similac Sensitive, Enfamil Lactofree
    • Alternative to Soy Formula for those avoiding lactose.
  • Hypo-allergenic Formula
    • Calorie = 20 kcal/oz; Carbohydrate = Corn or Sucrose; Protein = Hydrolyzed proteins
    • Examples: Alimentum, Nutramigen, Pregestimil
    • Only a small minority of infants have a true IgE-mediated milk protein allergy and benefit from these.
  • Non-allergenic Formula
    • Calorie = 20 kcal/oz; Carbohydrate = Corn or Sucrose; Protein = Amino Acids
    • Examples: Elecare, Neocate, Nutramigen AA
    • Infants who continue to have symptoms despite using hypo-allergenic formula can be placed on these amino acid based formulas.


Infant Formula: Mixing

  • Even if you don’t have a child yourself, this is IMPORTANT… because if the family is mixing formula incorrectly, the child may be in danger.
  • Formula comes in 3 general forms:
    • Ready to Feed
    • Liquid Concentrate
    • Powder
  • Standard Mixing:
    • Ready to Feed – none (as the name would imply); most expensive
    • Liquid Concentrate – 1:1 ratio of concentrate:water; made in batches and has to be used within 24 hours
    • Powder – 1 scoop of powder to 2 ounces of water (best to read manufacturer instructions); least expensive; can make individual feeds.
  • Incorrect mixing of formulas can lead to super-concentrated or dilute feeds and, subsequent, dangerous fluid and electrolyte disturbances.


Moral of the Morsel

  • Resist the Urge to Switch! In an effort to find a cause of, say, colic, many will want to switch formulas. At 3am in the ED, this is not the time to do that.
  • Know if a Switch made sense. If a child has been changed from a Cow’s Milk formula to a Soy formula because of an “allergy,” know that this is not likely the case.
  • Be a Mixing Master! Ask how the family is preparing a child’s feeds. This may have significant implications in your evaluation.



Green Corkins K1, Shurley T2. What’s in the Bottle? A Review of Infant Formulas. Nutr Clin Pract. 2016 Sep 19. PMID: 27646861. [PubMed] [Read by QxMD]

Wargo WF1. The History of Infant Formula: Quality, Safety, and Standard Methods. J AOAC Int. 2016 Jan-Feb;99(1):7-11. PMID: 26811237. [PubMed] [Read by QxMD]

Section on Breastfeeding. Breastfeeding and the use of human milk. Pediatrics. 2012 Mar;129(3):e827-41. PMID: 22371471. [PubMed] [Read by QxMD]

O’Connor NR1. Infant formula. Am Fam Physician. 2009 Apr 1;79(7):565-70. PMID: 19378873. [PubMed] [Read by QxMD]


Sean M. Fox
Sean M. Fox
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