Effects of soy formulas on mineral metabolism in term infants.

We studied 40 healthy term infants who received a soy-based formula containing either a single carbohydrate (glucose polymers) or dual carbohydrates (glucose polymers and sucrose). Ten exclusively breast-fed infants served as controls for the first four months of the study. All infants were studied at 2 weeks, 2 months, and 4 months of age for anthropometric development, biochemical values, and bone mineral content. There were no differences among the three groups in weight, length, or head circumference gains. Serum levels of calcium, phosphorus, magnesium, copper, 25-hydroxycholecalciferol, and alkaline phosphatase were also similar. However, at 4 months of age, the breast-fed group had a higher plasma zinc level than both formula-fed groups, and at 2 and 4 months of age, it had higher bone mineral content and bone density.