Renal Calcification

In Reply.— We appreciate the letter by Welsh and colleagues regarding our recent publication.1 Welsh et al appropriately suggest the possibility that some of the seven very low birth weight infants reported by us to have renal calcification without having received diuretics could have a variant of Bartter syndrome as previously described by Welsh's group2 and others.3-6 We hypothesized that the hypercalciuria in this group of infants resulted from exogenous supplementation of calcium via total parenteral nutrition and/or oral feedings combined with the infants' renal immaturity and inadequate renal tubular calcium reabsorption.