OBJECTIVES: I. Determine the role of magnesium deficiency in the pathogenesis of decreased serum vitamin D and reduced bone density in children with chronic cholestatic liver disease.

PROTOCOL OUTLINE: Patients receive magnesium sulfate IV over 1 hour on day 3. Patients then receive oral magnesium gluconate supplementation daily. Treatment with magnesium sulfate repeats once at 3-6 months.

Ages Eligible for Study:  3 Years   -   18 Years,  Genders Eligible for Study:  Both

Criteria

PROTOCOL ENTRY CRITERIA:

--Disease Characteristics--

• Diagnosis of liver disease with chronic cholestasis Nonsyndromic intrahepatic cholestasis Alagille's syndrome Extrahepatic biliary atresia
• Direct bilirubin greater than 2 mg/dL OR Bile acids greater than 20 micromoles/L
• No hepatic decompensation defined as one or more of the following: Ascites Peripheral edema PT at least 4 seconds longer than control Albumin less than 3 g/dL

--Patient Characteristics--

• Renal: No significant renal disease
• Cardiovascular: No significant cardiovascular disease
• Pulmonary: No significant pulmonary disease