Changes in serum zinc concentrations of some Canadian full term and low birthweight infants from birth to six months.

Serum samples were collected from 99 infants at birth, and when they were 1, 3 and 6 months old. Thirty-seven were preterm infants with a mean birthweight of 1880 g and 26--36 wk gestation; 24 were full term low birthweight with a mean birthweight of 2371 g and 38--42 wk gestation; and 38 were full term normal birthweight infants with a mean birthweight of 3590 g and 38--42 wk gestation. Serum zinc concentrations were determined by instrumental neutron activation procedures. No significant differences in serum zinc levels were apparent between sexes or among the 3 groups. Levels were highest at birth and declined during the first 3 months. Between 3 and 6 months, serum zinc levels remained fairly constant, and were lower than reported levels for North American adults. It is concluded that the decline in serum zinc concentration in all three groups was not significantly correlated with birthweight or gestational age and the low birthweight infants in this study did not show any evidence of zinc deficiency. The general decline in serum zinc levels appeared to be associated with low dietary zinc intakes.