Edema, hypoproteinemia, and zinc deficiency in low-birth-weight infants.

Three premature infants with zinc deficiency who had an unusual presentation with generalized edema and hypoproteinemia between 5 and 9 weeks of age are described. The infants were fed their own mother's milk, supplemented with a proprietary formula after the first 2 to 3 weeks of life. None of the infants had diarrhea, liver disease, or urinary protein loss. Treatment with oral zinc supplements led to rapid resolution of the edema, with an increase in values for serum proteins, alkaline phosphatase, and zinc. There was no recurrence of symptoms following discontinuation of zinc therapy 1 month later. At 1-year follow-up, all infants were doing well and had normal growth and development. As zinc plays a critical role in nucleic acid and protein synthesis, it is postulated that dietary zinc deficiency in the phase of rapid postnatal growth precipitated edema and hypoproteinemia in these infants. Zinc deficiency should be included in the list of causes of generalized edema in the low-birth-weight infant.