A genetic condition that results in inadequate levels of the enzyme glucose-6-phosphate dehydrogenase (G6PD) can cause sufferers to develop hemolytic anemia after using intravenous vitamin C treatment.[27] G6PD deficiency test is a common laboratory test. Vitamin C administration may acidify the urine, that could promote the precipitation of kidney stones or drugs in the urine.[26] Because oxalic acid is produced in the metabolism of vitamin C, hyperoxaluria can be caused by intravenous administration of ascorbic acid.[26]