To the Editor.—
Bhatia and Fomon1 have demonstrated that the quantities of calcium and phosphorus delivered to formula-fed infants may bear little relationship to the label claims. They also warned that, although their report was restricted to these two nutrients, other formula components may also be involved in discrepancies between what is present in the bottle and what is delivered to the infant. Confirmation of this prediction is provided by recent éxperience with measurements of zinc concentrations in Similac Special Care (Ross Laboratories, Columbus, OH) during the course of zinc balance studies on very low-birth-weight premature infants in our neonatal Clinical Research Center.