Osteomalacia and osteitis fibrosa in a man ingesting aluminum hydroxide antacid

A 53-year-old man with a history of long-term aluminum hydroxide antacid ingestion reported diffuse bone pain and multiple stress fractures over a two-year period. An undecalcified transiliac bone biopsy specimen revealed osteomalacia with osteitis fibrosa; plasma parathyroid hormone and cyclic AMP levels were normal. Following withdrawal of antacids and treatment with calcium and phosphorus, an initially elevated plasma, 1,25-dihydroxyvitamin D level fell to within the normal range, accompanied by decreased bone pain, healed stress fractures, and increased axial bone mineral content as determined by computed tomography of lumbar trabecular bone. Phosphate deprivation and 1,25-dihydroxyvitamin D excess may contribute to the poor mineralization and exaggerated resorption of bone observed in this syndrome. The clinical, biochemical, radiologic, and histologic features of previously reported cases are reviewed. Early recognition of this syndrome is important, since appropriate therapy promotes skeletal remineralization and prevents morbidity.