September 9, 2018

The results of a meta-analysis published on July 5, 2018 in BioMed Research International suggest that the addition of extra vitamin C to one's regular daily supplemental regimen could help shorten common cold duration and relieve some of its symptoms if initiated at the first sign of illness.

Researchers Li Ran and colleagues included seven randomized, placebo-controlled trials in their meta-analysis. The trials evaluated the effects of therapeutic doses of vitamin C consumed at the first signs of a common cold when taken alone or in addition to regular supplementation.

"As demonstrated by our meta-analysis comparing vitamin C with placebo, the combination of supplemental and therapeutic doses of vitamin C works on the common cold, while there is no statistically significant difference between mere therapeutic doses of vitamin C and placebo," the authors report. "To be specific, administration of extra doses of vitamin C at the onset of a common cold could help reduce the duration by about half a day, shorten the time confined indoors by about 10 hours, and relieve the symptoms of a common cold, including chest pain, fever, and chills."

Vitamin C is concentrated in white blood cells and declines during stress and infections. Research indicates that vitamin C's enhancement of immunity renders the body more capable of fighting off viruses, thereby reducing symptoms. Supplementing with vitamin C has been associated with improved antimicrobial and natural killer cell activities. The vitamin additionally helps protect the cells against reactive oxygen species.

In light of their findings, the authors suggest supplementing with a smaller dose of vitamin C each day to boost immunity and adding a larger dose of the vitamin when experiencing a cold to improve recovery.