Does Vitamin C prevent and treat the common cold?
From: The Cochrane Collaboration
- Hemilä, H., Chalker, E., Douglas, B., 1996. Vitamin C for preventing and treating the common cold, in: Cochrane Database of Systematic Reviews. John Wiley & Sons, Ltd.
- 29 trials involving 11,306 participants
- The paper is a systematic review / meta-analysis of all relevant trials.
- A search of the literature to discover whether oral doses of 0.2 g per day or more of vitamin C reduce the incidence, duration or severity of the common cold when used regularly every day or as therapy after onset of symptoms.
- Regular ingestion of vitamin C had no effect on common cold incidence in the ordinary population.
- However, it had a modest but consistent effect in reducing the duration and severity of common cold symptoms.
- No (without confidence)
- One large trial with adults reported equivocal benefit from an 8g therapeutic dose at the onset of symptoms, and two trials using five-day supplementation reported benefit.