Vitamin C supplementation in the critically ill patient

Curr Opin Clin Nutr Metab Care. 2015 Mar;18(2):193-201. doi: 10.1097/MCO.0000000000000148.


Purpose of review: Vitamin C is not only an essential nutrient involved in many anabolic pathways, but also an important player of the endogenous antioxidant defense. Low plasma levels are very common in critical care patients and may reflect severe deficiency states.

Recent findings: Vitamin C scavenges reactive oxygen species such as superoxide and peroxynitrite in plasma and cells (preventing damage to proteins, lipids and DNA), prevents occludin dephosphorylation and loosening of the tight junctions. Ascorbate improves microcirculatory flow impairment by inhibiting tumor-necrosis-factor-induced intracellular adhesion molecule expression, which triggers leukocyte stickiness and slugging. Clinical trials in sepsis, trauma and major burns testing high-dose vitamin C show clinical benefit. Restoration of normal plasma levels in inflammatory patients requires the administration of 3 g/day for several days, which is 30 times the daily recommended dose.

Summary: The recent research on the modulation of oxidative stress and endothelial protection offer interesting therapeutic perspectives, based on the biochemical evidence, with limited or even absent side-effects.

Publication types

  • Review

MeSH terms

  • Ascorbic Acid / blood
  • Ascorbic Acid / pharmacology*
  • Ascorbic Acid Deficiency / drug therapy
  • Burns / therapy
  • Critical Care
  • Critical Illness / therapy*
  • Dietary Supplements
  • Humans
  • Nutrition Therapy
  • Oxidative Stress / drug effects
  • Reactive Oxygen Species
  • Vitamins / pharmacology*
  • Wounds and Injuries / therapy


  • Reactive Oxygen Species
  • Vitamins
  • Ascorbic Acid