Latest Research
- Vitamin C was found to be successful in reducing the duration of colds (on average 8-14%) when it is taken as a daily preventative measure, or at the beginning of a cold. [1] [2]
- Vitamin C was shown to reduce the risk of getting a cold under extreme physical stress (marathoners and skiiers). [3]
Buy Supplement
How to Take
The Recommended Daily Intake (RDI) of vitamin C is 100-200mg. This is easily attained through the diet, so supplementation of such low doses is usually unnecessary. Higher doses of vitamin C, up to 2,000mg, are used to support the immune system (for athletes) or reduce the duration of the common cold.Nutrient-Nutrient Interactions
- Vitamin C increases effectiveness of Vitamin E by protecting it from oxidation.
- Vitamin C increases absorption of iron.
Safety Information
Toxicity and Side Effects
Vitamin C is LIKELY SAFE. Vitamin C at higher doses (2,000-6,000mg) may cause diarrhea due to incomplete absorption.Special Precautions And Warnings
Extremely high doses of Vitamin C may result in reversible kidney injury and possible renal failure. This is a fairly treatable condition carrying a good prognosis if readily treated, but it can be fatal if left untreated. Superloading vitamin C, particularly via intravenous injections, should be avoided unless it is done under medical supervision.Drug Interactions
No known drug interactionsReferences
[1] Anderson TW, Suranyi G, Beaton GH. The effect on winter illness of large doses of vitamin C. Can Med Assoc J. (1974)[2] Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. (2013)
[3] Douglas RM, et al. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. (2007)