What are infant formulas, and what's in them?
Infant formula is a nutritional product that is made from processed cow's milk or soybean products. Special processing makes cow's-milk formula more digestible and less likely to cause an allergic reaction than regular cow's milk.
Vitamins and minerals are added to infant formula. Formula can be used to provide all of a baby's nutritional needs before the age of 4 to 6 months.
Commercial formulas are made to be as similar to breast milk as possible. In very rare cases, powder formulas may contain some bacteria that could make a baby sick. The safety and nutrient content of infant formula is regulated by the U.S. Food and Drug Administration (FDA).
About half the calories in formula come from vegetable oils or a mixture of vegetable and animal fats. A baby's body requires fat for the production and growth of new cells and for high energy needs.
Milk sugar (lactose) is the main source of carbohydrate in most cow's-milk formula, just as in breast milk.
What types of formulas are there?
Several types of infant formulas are available. Usually cow's-milk formulas are tried first.
Babies need iron in addition to other vitamins and minerals. The iron in human milk is much more easily absorbed by infants than the iron in cow's milk. (But even breastfed babies need iron added to their diet.) Formula-fed babies can become iron-deficient if iron-fortified formulas are not used. Iron deficiency may cause severe complications in babies, such as weakness, abnormal digestion, and permanently reduced learning abilities. In the United States, a formula with an iron concentration of 6.7 mg/L or higher is considered iron-fortified. And the label must say that.footnote 1 The American Academy of Pediatrics recommends testing for anemia in babies at 12 months of age.
Some caregivers may be hesitant to feed an infant iron-fortified formula because of concern about side effects, such as gas or constipation. But these concerns have not been proved by research, and low-iron formulas are not recommended as a remedy for such symptoms. Although low-iron formulas are available, they should only be used in extremely rare situations on the advice of your doctor.
Other types of formulas are available for babies who have trouble digesting cow's-milk formulas. These are for babies who are at high risk of allergies or with a cow's milk allergy. Talk to your doctor before giving your baby one of these formulas.
- Soy formulas may be recommended for babies who are unable to tolerate cow's-milk formulas or for vegetarian parents who don't want to feed their babies animal products. Or soy formulas may be chosen for cultural, ethical, or religious reasons.
- Soy formula is not recommended for all infants. It should not be given to any infant who has a soy protein allergy.
- Lactose-free formulas are used for babies who are lactose-intolerant. This is a rare condition in babies.
- Hydrolyzed protein or amino acid formulas are used for babies who cannot tolerate formulas made from cow's milk or soy.
Do not use homemade formulas, such as those that use evaporated milk. These do not contain the nutrients and supplements your baby needs. They could also make your baby sick.
How do I prepare them?
You can buy formula as a powder or as a concentrated or ready-to-feed liquid. Ready-to-feed formulas cost the most. But some caregivers find their convenience worth the extra cost. You must add cool, safe water to powders and concentrates. You must add cool, safe water to powders and concentrates. Be sure to follow the directions on the label and use the measuring device that comes with the product.
Cover and store your open cans of ready-to-feed and concentrated liquid product in the refrigerator for no longer than 48 hours. Cover and store both opened and unopened cans of powder formula in a cool, dry place, not in the refrigerator. You can use the powder product for up to 4 weeks, if it's stored right. Don't leave prepared formula out of the refrigerator.
Also, follow-up formulas for toddlers are available and usually contain more iron and other nutrients than other formulas. They can be used for older babies who are switching from formula to whole cow's milk. Most babies make this transition easily.
In some cases, doctors recommend adding a thickening agent to a baby's formula. Before you use one, talk to your doctor about the risks and benefits. If you have any trouble feeding your baby, talk to your doctor or nurse.
Current as of: March 1, 2023
Author: Healthwise Staff
Medical Review:John Pope MD - Pediatrics & Kathleen Romito MD - Family Medicine & Elizabeth T. Russo MD - Internal Medicine