Oxalate excretion during carbohydrate infusions.

Oxalate metabolism was assessed in normal rats and rats deficient in vitamins B-1 and B-6 during intravenous infusions of solutions containing glucose, fructose, sorbitol or xylitol. Urinary excretions of oxalate, glyoxylate and glycine were considerably increased in vitamin B-6 deficient rats infused with xylitol. Significant amounts of 14C-oxalate were excreted only in vitamin B-6 deficient rats infused with U 14C-xylitol. Correction of vitamin B-6 deficiency resulted in a return to normal of urinary oxalate excretion and percentage of U 14C-xylitol excreted as 14C-oxalate. The results suggest that xylitol metabolism produces an increased activity in pathways leading to oxalate formation in vitamin B-6 deficient rats.