Abstract Summary

Objective: This study investigates the effectiveness of high-dose vitamin C supplementation in reducing the duration and severity of the common cold.

Context: The common cold is a highly prevalent viral infection of the upper respiratory tract. While self-limiting, it causes significant economic impacts due to missed work and school. Vitamin C supplementation has been frequently promoted to prevent and treat colds, but evidence on its efficacy remains conflicting.

Methods Used: A randomized, double-blind, placebo-controlled trial was conducted on 172 adults with newly acquired upper respiratory tract infections. Participants were randomized to receive either 8,000 mg/day of vitamin C or a placebo for the duration of their illness. Symptom scores were self-assessed daily.

Researchers' Summary of Findings: Supplementation with high-dose vitamin C did not significantly reduce the duration or severity of the common cold in the general population. However, benefits were observed in subgroups with initially lower vitamin C levels or those under heavy physical stress, warranting further targeted research.

DOI: 10.1016/j.nut.2020.111055