Clinical zinc deficiency during zinc-supplemented formula

A 2 1/2-month old preterm infant had failure to gain weight with high caloric intake, and had generalized persistent dermatitis and mild diarrhea. The patient was being fed zinc-supplemented cow's-milk-based formula (Osterfeed). High caloric intake of 8 weeks' and topical treatment of 11 weeks' duration were futile. A thorough investigation revealed low serum zinc concentration. Administration of zinc sulfate 150 mg/day resulted in brisk weight gain and complete clearing of skin lesions. The infant maintained normal levels of zinc 4 months after zinc therapy was discontinued, while being fed unmodified cow's milk and a diet of corn flour. The probability that zinc-supplemented formulas do not meet the high zinc requirements of premature infants is raised. The importance of plasma or serum zinc examination in preterm infants with slow growth velocity or failure to gain weight despite adequate caloric intake, with or without skin lesions and diarrhea, is emphasized.