MIXED — Does Vitamin C Actually Prevent Colds?

Analysis summary

Scientific consensus indicates Vitamin C does not prevent colds for the general public, though it can reduce risk for athletes and slightly shorten symptom duration if taken daily.

Evidence profile

Key findings

• Large-scale studies show that routine Vitamin C supplementation does not prevent the common cold in the general population.
• Vitamin C can reduce the risk of catching a cold by approximately 50% in people under extreme physical stress, such as marathon runners, skiers, and soldiers in subarctic conditions.
• Regular daily use of Vitamin C may modestly shorten the duration of a cold (by about 8% in adults and 14% in children) and reduce symptom severity.
• Taking Vitamin C only after cold symptoms have already started has no consistent effect on the duration or severity of the illness.

Citations