A variety of formulas are available for infants younger than 12 months old who are not drinking breast milk. Infant formulas vary in nutrients, calorie count, taste, ability to be digested, and cost.

Guidelines for infant formulas and normal infant feeding based on human breast milk are available from the American Academy of Pediatrics (AAP).

SPECIFIC TYPES OF FORMULAS

Standard milk-based formulas:

• Almost all babies and infants do well on these formulas. Fussiness and colic are common problems. Most of the time, cow's milk formulas are not the cause of these symptoms and parents do not need to switch to a different formula.
• These formulas are made with cow's milk protein that has been changed to be more like breast milk. Lactose and minerals from the cow's milk, as well as vegetable oils, minerals, and vitamins are also in the formula.

Soy-based formulas:

• These formulas are made using soy proteins. They do not contain lactose. The American Academy of Pediatrics recommends soy formulas for parents who do not want their child to eat animal protein, and for infants with galactosemia or congenital lactase deficiency.
• Soy-based formulas have not been proven to help with milk allergies or colic. Babies who are allergic to cows' milk may also be allergic to soy milk.

Hypoallergenic formulas (protein hydrolysate formulas):

• This type of formula may be helpful for infants who have true allergies to milk protein, and for those with skin rashes or wheezing caused by allergies.
• Hypoallergenic formulas are generally much more expensive than regular formulas.

Lactose-free formulas:

• These formulas are used for galactosemia, congenital lactase deficiency, and primary lactase deficiency. Lactase deficiency most often begins after a child is 12 months old. The condition is diagnosed using special tests.
• A child who has an illness with diarrhea usually will not need lactose-free formula.

Special formulas that should be used only under a health care provider's supervision:

• Reflux formulas are pre-thickened with rice starch. They are usually needed only for infants with reflux who are not gaining weight or who are very uncomfortable.
• Formulas for premature and low-birthweight infants have extra calories and minerals to meet the needs of these infants.
• Special formulas may be used for infants with heart disease, malabsorption syndromes, and problems digesting fat or processing certain amino acids.

Newer formulas with no clear role:

• Formulas with long-chain polyunsaturated fats (such as arachidonic acid [AA] and docosahexaenoic acid [DHA] claim to improve eye and brain development. However, these claims are not well proven.
• Toddler formulas are offered as added nutrition for toddlers who are picky eaters. To date, they have not been shown to be better than whole milk and multivitamins. They are also expensive.

Most formulas can be purchased in the following forms:

• Ready-to-use -- do not need to be prepared with water
• Powdered formulas -- must be mixed with water, but are the least expensive form
• Concentrated liquid formulas -- also need to be mixed with water