Hypernatremia in breast-fed newborns.

excessive free water loss, excessive sodium intakeor diminished free water intake. The last mecha-nism seems the explanation in this and the fourother reported cases.All five infants shared common features: theywere emaciated, less than 1 month of age andexclusively breast-fed-that is, with no water orformula supplementation (Table 1). Three of theinfants were "sleepy," difficult to keep awake forfeeding and content to starve