THE USE OF 1,25-DIHYDROXYCHOLECALCIFEROL (1,25-(OH)2 D) IN THE TREATMENT OF RICKETS WITH NEONATAL LIVER DISEASE

Abstract

Rickets associated with liver disease is believed to be caused by malabsorption of vitamin D and Ca and decreased hepatic 25-hydroxylation of vitamin D. 1,25-(OH)2D, normally synthesized in the kidney from 25-hydroxyvitamin D (25-OHD), theoretically should bypass the blocks in vitamin D metabolism. Two patients had radiographic and biochemical evidence of rickets with severe neonatal hepatitis and extrahepatic biliary atresia. Both received phenobarbital to enhance bile flow. 1,25-(OH)2D was initially given orally (0.10 μg/kg/day) without improvement. Thereafter, i.m. divided doses (0.20 μg/kg/day) were given with complete biochemical, bone mineral (photon absorptiometric analysis) and radiographic evidence of healing.I.M. 1,25-(OH)2D which theoretically overcomes blocks in vitamin D metabolism, can be effectively used in infantile biliary rickets. Healing occurs in spite of continuously low 25-OHD. The need for higher doses of 1,25-(OH)2D, four times the “physiologic dose”, may reflect enhanced catabolism or end organ resistance.