Since the initial use of central venous catheters for infusion of concentrated nutrient solutions,1 total parenteral nutrition (TPN) has become increasingly used for treating patients with various intestinal abnormalities. Experience with TPN, whereby patients received their total nutritional requirements by infusion during ten to 16 nighttime hours at home, has been reported.2
Several metabolic abnormalities, including hyperammonemia in the newborn3 and deficiencies of essential fatty acids,4 zinc,5 copper,6 and phosphate,7 have been encountered with the long-term use of TPN.
A metabolic bone disease has been described in adults who received long-term TPN,8,9 and severely subnormal levels of 1,25-dihydroxyvitamin D (1,25-[OH]2D) have been found.10 We encountered rickets in three infants who received long-term TPN despite the administration of "adequate" amounts of ergocalciferol (vitamin D2).11
Methods.—Ten infants, aged 1 to 5 months, were treated for seven to 17