Although acute vitamin B-6 deficiency increases urinary oxalate excretion, the effects of marginal vitamin B-6 status are unknown. Mild vitamin B-6 depletion was induced in eight healthy young women by feeding a low vitamin B-6 lacto-ovo-vegetarian natural foods diet for 27 days. The basal diet contained 0.45 mg vitamin B-6 and 1.55 g/kg body weight protein. Although measures of vitamin B-6 status indicated that the women had marginal vitamin B-6 status, no effect was seen on 24 hour urinary oxalate. The women were then repleted with 1.26 mg vitamin B-6 for 21 days, followed by repletion with 1.66 mg for 21 days, then 2.06 mg vitamin B-6 for an additional 14 days. At the end of the 56 day repletion period, 24 hour urinary oxalate was unchanged from either adjustment or depletion values. Vitamin B-6 depletion associated with consumption of a low vitamin B-6 diet did not affect 24 hour urinary oxalate. Marginal vitamin B-6 status is unlikely to be a cause of calcium oxalate kidney stones in a young healthy population.