Many parents think iron-fortified formulas can cause colic, constipation, diarrhea, reflux (spitting up) or other digestive problems. These misguided parents buy "low-iron" instead of "iron-fortified" formulas.

According to the American Academy of Pediatrics Committee on Nutrition, "low iron" is the wrong choice and only iron-fortified formula (containing between 4 and 12 mg/L iron) should be used, unless instructed otherwise by a physician.

In fact, there is no evidence that iron-fortified formulas lead to any digestive problems. However, there is definite evidence that infants fed a low-iron formula end up with iron deficiency anemia (not enough red blood cells) more often than those fed an iron-fortified formula. Studies have shown that about one out of three 9-month-olds fed a low-iron formula had iron deficiency anemia, while fewer than one in 100 had anemia when the infant was fed an iron-fortified formula.

Because iron is important for making red blood cells, infants who do not get enough iron can develop anemia. Iron deficiency anemia is a serious problem for infants, if not treated. It can lead to fussiness, weakness, muscle fatigue, poor appetite, abnormal gastrointestinal movement and, perhaps most importantly, developmental delays and a permanent decrease in cognitive ability.

For almost 30 years, the American Academy of Pediatrics has recommended that mothers breast-feed, if possible, or use an iron-fortified formula. The Academy continues to warn against the use of low-iron formula. In spite of this recommendation, many parents still use low-iron formulas.

In addition to the widely held misconceptions about iron causing stomach distress, the American Academy of Pediatrics suggests that the bad practice of using low-iron formula may continue because some people assume that since there is a low level of iron in breast milk, there is no need to buy an iron-fortified formula.

But the iron in breast milk can be absorbed by the body more efficiently than the iron in formulas. Studies show that breastfed infants are far less likely to develop iron deficiency anemia than those fed low-iron formulas.

To address these ongoing misperceptions and prevent iron deficiency anemia during infancy, the Academy now strongly recommends that the manufacture of low-iron formulas be discontinued — or at least that these products be labeled to warn parents that they are "nutritionally inadequate" for infants from birth to 1 year old.