Methemoglobinemia and acute hemolysis induced by high intravenous doses of vitamin C in a COVID-19 patient with unrecognized glucose-6- phosphate-dehydrogenase deficiency

In glucose-6-phosphate-dehydrogenase deficiency (favism), exposure to oxidant agents can trigger hemolytic crises. The intravenous administration of very high doses vitamin C was proposed as a treatment for severe coronavirus disease 2019 (COVID-19) pneumonia. Unlike low doses, (>6 gr daily) promote H2O2 formation, oxidation hemoglobin methemoglobin and, eventually, anemia in patients with favism. We here describe the case 77-year old man hospitalized COVID-19 pneumonia and treated mean daily dose 9.5 during first 6 days. He developed methemoglobinemia anemia, which improved after interruption treatment. Previously unrecognized glucose- 6-phophate-dehydrogenase diagnosed. This Cinduced patient indicates need screening before or long period.