Age-dependent serum sulfate levels in children and adolescents.

We measured inorganic sulfate in 100 microliters of deproteinized serum by microassay, using the 133Ba precipitation method. Infants and children under 3 yr (n = 46), children from 3 to 9 yr of age (n = 27) and adolescents (10-18 yr, n = 12) in a hospitalized population, and healthy adults (n = 10), were studied. An age-dependent curvilinear regression for serum sulfate characterizes the first group: the mean serum sulfate value falls from 0.47 mmol/l on the first day of life to 0.33 mmol/l at 36 months. Thereafter the mean value is about 0.33 mmol/l. The 95% confidence intervals were defined for each group.