Research published in Nutrients (July 9, 2014; Volume 6, Issue 7, Pages 2572–2583) examined the effects of vitamin C supplementation on the common cold in individuals with low vitamin C status. The study included 28 men between the ages of 18 and 35, all of whom had low baseline vitamin C levels.
Participants were randomly assigned to receive either 1,000 mg of vitamin C per day or a placebo for eight weeks. During the study period, 11 participants in the placebo group developed a cold, compared with 7 participants in the vitamin C group. Among those in the vitamin C group who did develop colds, the duration of illness was 59% shorter than in the placebo group.
In addition, during the final two weeks of the trial, participants receiving vitamin C showed a modest increase in physical activity compared with those receiving placebo. The authors concluded, “These data suggest significant health advantages associated with vitamin C supplementation in a population with adequate-to-low vitamin C status.”
