Piridoxilate-induced oxalate nephropathy can lead to end-stage renal failure.

A 71-year-old woman was admitted with end-stage renal failure and histological evidence of oxalosis. This case of diffuse renal tubular crystal calcium oxalate deposits seems to be induced by long-term piridoxilate therapy (10 years) or simultaneous intake of both piridoxilate and vitamin C (500 mg/day for 6 months), since no other cause of secondary oxalosis could be found. So, it seems necessary to monitor the serum creatinine level, especially in the elderly, during piridoxilate therapy and to avoid high vitamin C intakes in patients under such treatment to prevent development of renal insufficiency.