Effects of oral pyridoxine upon plasma and 24-hour urinary oxalate levels in normal subjects and stone formers with idiopathic hypercalciuria.

The effect of pyridoxine hydrochloride, 200 mg/day (0.97 mmol/day) for 3 weeks, upon plasma and urinary oxalate has been determined in ten normal subjects and seven patients with idiopathic hypercalciuria while both groups were on low-oxalate diets. Patients had higher basal urinary oxalate levels than normal subjects. In normal subjects pyridoxine administration decreased plasma oxalate levels and raised urinary oxalate. The patients showed no change in either plasma or urinary oxalate.