Serum calcium and phosphorus in premature and full-term infants; a longitudinal study in the first three weeks of life.

Abstract

Hypocalcemia with or without tetanic symptoms has frequently been observed in sick infants. This is particularly common during the first month of life.* In addition, tetany of the newborn occurs in infants who are not otherwise ill. These cases often present difficult etiologic and therapeutic problems. When many serum calcium determinations are done on young infants, frequent cases of hypocalcemia are discovered. An impression was gained that newborn infants who are premature or ill with any serious disease tend to have hypocalcemia, not necessarily associated with symptoms of tetany. The following questions therefore arose: What are the normal fluctuations or variations of the serum calcium level in full-term and premature infants during the neonatal period? Which factors influence the serum calcium level? Can the symptomatology of the infants be correlated with the serum calcium level, considering also such other influences as the serum potassium level and the