*Effect of Ascorbic Acid on the Kidneys DOI: http://dx.doi.org/10.5772/intechopen.111913*

acid's antioxidant activity suppresses P-gp expression and is thought to have a positive effect on drug pharmacokinetics [39].

Acute renal dysfunction caused by contrast agents used in imaging methods occurs at a rate of 2% in healthy people and 11–45% in people with diabetes or chronic kidney disease. One study evaluated the use of vitamin C to prevent nephropathy. The study revealed that vitamin C had no effect on contrast-induced nephropathy. However, due to its antioxidant effect, it helped to reduce the oxidant load [40].

Recent studies have examined the effect of vitamin C on hemodynamic parameters in septic shock. Vasopressor therapy is required in the treatment of septic shock. These patients received parenteral vitamin C in addition to their usual treatment. When compared to other patients, parenteral vitamin C administration did not change the length of stay in intensive care; however, a statistically significant reduction in mortality rate was observed. In addition, a statistically significant decrease in the amount and duration of vasopressor administration has been reported [38, 41, 42]. In addition to these studies, there have been reports that vitamin C use in septic shock causes nephropathy.

Parenteral vitamin C was administered to patients hospitalized for sepsis in a retrospective study that reported that parenteral vitamin C administration causes nephropathy. However, it was reported that high doses of parenteral vitamin C caused nephrotoxicity; there was no reduction in the mortality rate [43, 44].

Hyperoxaluria has a nephrotoxic effect in the renal tubules. In two cases admitted to hospital with severe burns, high doses of parenteral vitamin C were administered as part of treatment. Two patients developed severe oligoanuric acute kidney injury after receiving 101 g and 224 g of vitamin C twice daily, respectively. The death occurred in two patients. Oxalate nephropathy was reported to have developed in two cases at autopsy [45]. A female patient in intensive care for septic shock was given parenteral vitamin C for two months, according to a 2017 case report. A biopsy revealed that the patient had oxalate nephropathy [46, 47].
