Ages and Stages

Before 1980, some infants were fed chloride-deficient formulas. Hypochloremic alkalosis developed, causing those infants to exhibit cognitive delays, language disorders, and impaired visual motor skills. As a result, the U.S. Congress passed a law requiring infant formula to contain a minimum chloride content of 55 to 65 mg/100 kcal and a maximum of 150 mg/100 kcal. Breast milk contains about 420 mg/L, and undiluted cow's milk contains 900 to 1,020 mg/L. Infant formula contains 10.6 to 13.5 mEq/L; formula for older infants (follow-up formula), 14 to 19.2 mEq/L.

Despite the regulation of chloride in infant formula, hypochloremic alkalosis isn't uncommon in children and is commonly seen in neonates. Hypochloremic alkalosis may be caused by diuretic therapy in bronchopulmonary dysplasia or by NG suctioning. It may also be seen in infants with chloride-wasting syndromes resulting from renal causes (Bartter syndrome), intestinal causes (congenital chloride-losing diarrhea), or chloride loss from cystic fibrosis.