Formation of oxalate in pyridoxine or thiamin deficient rats during intravenous xylitol infusions.

Glucose, fructose, sorbitol and xylitol were assessed as precursors of oxalate in normal rats and rats deficient in thiamin or vitamin B-6. Urinary excretions of oxalate, glyoxylate and glycine were increased significantly in vitamin B-6 deficient rats infused with xylitol when compared with all other groups. Using [U-14C]xylitol, oxalate was shown to be derived directly from this polyalcohol in vitamin B-6 deficient rats. These results suggest that vitamin B-6 deficiency may be a factor contributing to oxalate crystal deposition seen in some patients infused with xylitol.