Osmolalities of Infant Formulas

The osmolalities of breast milk and of 36 products that may be fed to infants were determined by the freezing-point depression method. A wide range of osmolality was observed among formulas that provide 67 kcal/100 ml, and many have osmolalities greater than 400 mOsm/kg of water. Reconstituted powdered formulas have osmolalities that are widely varied from batch to batch, are greater when prepared by scoop measures when the osmolalities of corresponding ready-to-feed formulas, and are greater than the osmolalities of the formulas prepared by weighed measures from the manufacturer's formulation. The osmolality of products for oral consumption should be considered in the selection of formulas for preterm infants.