Is vitamin C effective in treating the common cold?

Jenny, a stay-at-home mum, presented with an URTI. After a clinical assessment, I advised her that she had the common cold.

She said, “Yeah, I thought so. I just wanted to be sure. So I should just rest and take some vitamin C right?”

Vitamin C has been widely used for the treatment of colds since the 1970s, when Linus Pauling controversially promoted the idea in his book, Vitamin C and the Common Cold.

What does the research evidence say?

A SEARCH for “vitamin C and cold” in the Cochrane Library finds a Cochrane systematic review published in 2010 examining the evidence for vitamin C as a treatment for colds and vitamin C as prophylaxis.1 

Using PubMed, there are no new randomised controlled trials (RCTs) using vitamin C for colds since 2010. 

We will examine the Cochrane review by Hemilä et al (2010) in detail.