Vitamin C has long been heralded as a helpful remedy to the common cold. We’ve all likely been advised to pop a few tablets when we’re coming down with something, and many take it every day to ward off the potential threat of a new virus.
But is there any science to back this up?
According to a new study, no. A systematic review of the existing scientific literature conducted by researchers in Helsinki found that taking vitamin C supplements did not reduce the likelihood of catching a common cold, reports WedMD.
There was one rather surprising caveat to this finding: among those exposed to brief but intense periods of physical exercise, vitamin C intake did have an effect.
“I have generally not been impressed by its usefulness,” says Reinhold Vieth, a clinical biochemist at Mount Sinai Hospital.
Veith says that the study results fit well with his own perspective on the vitamin. Vieth was also impressed by the quality of the report, published by The Cochrane Collaboration, an international project specifically dedicated to producing comprehensive reviews of existing medical literature.
“Cochrane is what drives policy makers who want to refer to ‘evidence based medicine’ as a basis for public policy," says Veith. The study looked at 29 previously conducted trials that included 11,306 participants.
So while the reports appear to be good news if you’re an athlete or a soldier with the sniffles, those of us who pop vitamin C at the slightest cough are left looking a little foolish.
There was some encouraging news for the less active who regularly take vitamin C.
The study also found that regular consumption of vitamin C could marginally reduce the duration of colds — not the likelihood of catching one — but this only applied to those who took the supplements before the first sign of sickness. Suddenly pounding vitamin C when you start to get sick — also known as therapeutic use — does not shorten cold duration.
The report’s concludes that “routine vitamin C supplementation is not justified” for the prevention of colds, but adds that it may be useful in “people exposed to brief periods of severe physical exercise.”
“I am surprised that the trials in athletes were not discussed more,” says Vieth, describing the impact vitamin C had on them to be “impressive.”
In the studies that looked at groups of marathon runners, skiers and soldiers, the likelihood of catching a cold was halved amongst those who took vitamin C.
The report goes on to say that regular folk who want to continue to take vitamin C are fine to do so. Only because no harm can come of it and it has been shown to have a modest effect on cold duration.