BONE DISEASE AND CALCIUM ABSORPTION IN PRIMARY BILIARY CIRRHOSIS: With Special Reference to Vitamin-D Therapy

Calcium absorption and bone disease have been investigated in twelve patients with primary biliary cirrhosis before and after treatment with intramuscular vitamin D. Calcium absorption measured by whole-body retention of calcium-47 after oral calcium-47 as chloride in water correlated well with estimation of absorption by plasma-levels of calcium-47. Before treatment, calcium absorption was subnormal in four patients. Impairment correlated well with the intensity of jaundice and less well with the fæcal-fat excretion. Absorption of aqueous calcium-47 chloride was normal when measured either between 1 and 3 months or after 12 months of vitamin-D treatment. Crush fractures of vertebræ were present in four patients, but none of the twelve had radiological signs of osteomalacia. Bone-biopsy specimens showed osteomalacia in only one of the twelve patients but seven excreted an abnormally low percentage of infused calcium and may have had early osteomalacia. After 1-3 months of treatment with vitamin D, calcium-infusion tests remained abnormal, but after 12 months were restored to normal in each of five patients on whom they were done. In spite of this, further bone fractures devloped in three patients. Although vitamin-D therapy repairs the defective absorption of a soluble calcium salt, and prevents osteo- malacia, it does not halt the progression of bone disease in patients with primary biliary cirrhosis.