Rickets associated with cholestasis and parenteral nutrition in premature infants.

Fourteen premature infants on prolonged total parenteral nutrition (TPN) exhibited radiographic evidence of rickets. All had received supplementary doses of vitamin D that, in retrospect, may have been inadequate. Cholestasis and rickets resolved in the 10 surviving infants after they were started on oral feelings, which corrected their hypophosphatemia. On the assumption that they might be deficient in vitamin D, they were given high doses of it. In retrospect, it appears probable that rickets in such cases is caused by hypophosphatemia, due to inadequate phosphorus intake, and that vitamin D deficiency is of little or no importance.