Severe vitamin C deficiency associated with continuous renal replacement therapy: A case report

Hypovitaminosis C is prevalent in critically ill patients. Continuous renal replacement therapy (CRRT) clears vitamin C, increasing the risk for vitamin C deficiency. However, recommendations for vitamin C supplementation in critically ill patients receiving CRRT vary widely, from 250 mg/day to 12 g/day. This case report describes a patient who developed a severe vitamin C deficiency after prolonged CRRT despite receiving ascorbic acid (450 mg/day) supplementation in her parenteral nutrition. This report summarizes recent research investigating vitamin C status in critically ill patients receiving CRRT, discusses the patient case, and provides recommendations for clinical practice. In critically ill patients receiving CRRT, the authors of this manuscript suggest providing at least 1000 mg/day of ascorbic acid to prevent vitamin C deficiency. Baseline vitamin C levels should be checked in patients who are malnourished and/or have other risk factors for vitamin C deficiency, and vitamin C levels should be monitored thereafter every 1-2 weeks.