Urinary sodium to creatinine ratio in healthy infants.

Rationale Sodium is essential for adequate growth; the daily requirement in infants is 2 to 3 mmol/kg/d. Objectives The study aimed to establish a reference range for the ratio of urinary sodium (UNa) to creatinine (UCr) in healthy infants in a suburban setting in the United States. Methods UNa and UCr were measured in healthy infants and UNa:UCr was calculated.