**3. The effect of ascorbic acid on nephropathy**

The formation of calcium oxalate crystals in the renal tubules causes acute and/ or chronic renal function impairment. This condition is defined as oxalate nephropathy. Biopsy and radiology both show the formation of nephrocalcinosis in the renal parenchyma [37] .

There is disagreement among scientists on the effect of ascorbic acid on nephropathy as well as on the risk of stone formation. Biopsy and radiology both show the formation of nephrocalcinosis in the renal parenchyma.

A study was conducted on the prevention of acute kidney injury in Covid-19 patients with vitamin C. Covid-19 initiates a cytokine storm in the body, causing organ damage through inflammatory reactions. Inflammatory cytokines damage the renal tubules and impair renal function. Vitamin C's antioxidant effect prevents the formation of ROS caused by cell damage. Vitamin C improves renal function by lowering plasma urea and creatine levels as well as renal tissue malondialdehyde levels [38].

Ascorbic acid is a vitamin known to have antioxidant properties. P-glycoprotein (P-gp) is a transporter protein expressed in the kidney and P-gp expression is induced by ROS. Many drugs are excreted more effectively when P-gp is present. Ascorbic
