Table 2.

Teaching points

We describe 2 cases of multifactorial acute tubular injury with oxalate nephropathy in critically ill patients with COVID-19.

Oxalate nephropathy was caused by high-dose i.v. vitamin C supplementation, administered to counteract a COVID-19–related cytokine storm during sepsis.

Vitamin C causes hyperoxaluria through endogenous conversion of ascorbic acid to oxalate.

Oxalate nephropathy can substantially aggravate kidney tubular injury of any type and jeopardize its recovery.

COVID-19, coronavirus disease 2019.