Soy-based formulas have been available since 1962, and are the most widely used alternative to milk-based formulas. Instead of milk-protein, the protein in these formulas comes from soybeans.
Just like cow's milk-based formulas, soy-based formulas contain all the necessary nutrients (including iron fortification, adequate fat and calcium) and calories required for normal growth and development. Children grow and develop normally on soy-based formulas and do not need any additional supplementation, with the possible exception of fluoride drops depending on the concentration of fluoride in the drinking water in your area.
How long can a baby be on soy formula?
In most cases soy formulas are used because a baby is allergic to cow's milk protein. Children can remain on soy-based formula for the first two years of life, or until they outgrow the milk allergy, whichever comes first. However, if the milk allergy persists, beyond two years of age there are other milk free alternatives available. The specifics are based on the individual situation. Practically speaking, the rest of the diet should be normal (dairy-free of course), including starting solids by four months of age. Remember also to use the soy formula when preparing cereal for your baby.
Important: soy-based formula should not be confused with the kind of soymilk(soy-drinks) that is commonly found in the dairy section of many grocery stores. Soy-based formulas are a good substitute for milk-based formulas and cow's milk generally during the first two years - but soymilk is not. It's low in calcium, and hasn't been fortified with other important nutrients that an infant needs during the important first two years of life.