Bone oxalate in a long-term hemodialysis patient who ingested high doses of vitamin C

We performed a bone biopsy on a patient who had been receiving hemodialysis for 23 years. The bone had oxalate deposition. Previous bone biopsies had shown osteitis fibrosis without oxalate deposition. The osteoid area was increased (11% of bone area), as was the fibrosis (6.1% of tissue area) and aluminum deposition (38% of surface). Bone formation rate was normal (259 mu 2/mm2/d). We examined bone biopsies of 22 patients who had been receiving hemodialysis for over 10 years, and none had oxalate deposits. We discovered that our patient had been ingesting 2.6 g/d of vitamin C. The bone oxalate deposition may have been caused by the ingestion of high doses of vitamin C.