Effect of Vitamin C on mortality of critically ill patients with severe pneumonia in intensive care unit: a preliminary study

BMC Infect Dis. 2021 Jun 29;21(1):616. doi: 10.1186/s12879-021-06288-0.


Background: Critically ill patients frequently suffer from vitamin C deficiency. Previous studies showed that high doses of vitamin C administration had conflicting results on clinical outcomes in patients with severe sepsis, burns, and trauma. Because of the high incidence and morbidity/mortality with severe pneumonia, we aimed to investigate the effect of administration of high dose vitamin C in critically ill patients with severe pneumonia.

Methods: Eighty critically ill patients with pneumonia were enrolled in this randomized double-blinded clinical trial. Patients with a CURB-65 score > 3, one major criterion, or ≥ 3 minor criteria were considered as severe pneumonia. Patients were randomly assigned to intervention or placebo groups receiving standard treatment plus 60 mg/kg/day vitamin C as a continuous infusion or normal saline in the same volume correspondingly for 96 h. Serum levels of vitamin C were noted at baseline and 48 h after vitamin C administration. Duration of mechanical ventilation, ICU length of stay, PaO2/FiO2, and mortality rate were noted for all patients till the 28th day. Any complications related to the vitamin C administration were recorded.

Results: Duration of mechanical ventilation and vasopressor use were significantly lower in the intervention group (p: < 0.001 and 0.003, respectively). Baseline levels of vitamin C in both groups did not have a significant difference but its levels increased in the intervention group and decreased in the control group during the study period. Mortality rate insignificantly decreased in the intervention group (p = 0.17). Three patients showed hypotension and tachycardia during the administration of vitamin C which was self-limited with decreasing the dose of vitamin C. Our results showed that the intravenous administration of a relatively high dose of vitamin C to critically ill patients with severe pneumonia was safe and could decrease the inflammation, duration of mechanical ventilation, and vasopressor use without any significant effect on mortality.

Trial registration: IRCT registration number: IRCT20190312043030N1, Registration date: 2019-08-26, Seied Hadi Saghaleini.

Keywords: Critically ill; Mortality; Pneumonia; Vitamin C.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Administration, Intravenous
  • Adult
  • Aged
  • Ascorbic Acid / administration & dosage*
  • Ascorbic Acid / blood
  • Critical Care / methods*
  • Critical Illness
  • Double-Blind Method
  • Female
  • Humans
  • Intensive Care Units*
  • Length of Stay
  • Male
  • Middle Aged
  • Pneumonia / blood
  • Pneumonia / drug therapy*
  • Pneumonia / mortality*
  • Respiration, Artificial / adverse effects
  • Severity of Illness Index*
  • Treatment Outcome
  • Vitamins / administration & dosage*


  • Vitamins
  • Ascorbic Acid