Patients receive either daily choline chloride in their total parenteral nutrition (TPN) solution or their usual TPN. The TPN is given intravenously over a 12 hour period beginning at approximately 9 PM nightly. Therapy continues for 24 weeks. Adjustments in the daily dose of choline provided may be required based on plasma free choline levels and patient tolerance. Additionally, all patients record the type and amount of their food intake on a daily basis.