Taking Vitamin C Probably Doesn’t Fix A Cold — But You Still Need It
Stocking up on vitamin C is something we’ve been taught to do at the first sign of a cold, whether it’s in the form of fruit, orange juice or a supplement. But where did this belief that vitamin C can ease a cold come from, and does it really do anything?
The widespread use of vitamin C as a common cold treatment started in the 1970s when American chemist and author Linus Pauling published several books on the subject as a result of extensive research, although his findings were contested by many in the scientific community.
Discussion was sparked again recently by a University of Helsinki research paper that reviewed old studies into vitamin C’s ability to reduce symptoms and shorten the length of a cold.
Dr Harri Hemil? assessed the findings of animal studies where varying levels of vitamin C were administered to different groups, and concluded that a six-gram dose daily could shorten the duration of a cold by 17 percent, and a dose of vitamin C on the first day of cold symptoms shortened its length by 19 percent.
Notably, the groups that received the highest dose of vitamin C saw better results than those that received half the amount, as did groups that took it only on the first day they were sick.
Dr Hemil? argues in his paper that this is good reason for more research to be done into vitamin C as a common cold cure, looking especially at whether extra-large doses are beneficial, and at what stage they should be taken.
Alexander J Michels Ph.D from Oregon State University’s Linus Paling Institute (co-founded by the father of vitamin C research), who looks at the role of micronutrients in aging and disease, says the research Hemil? analysed needs further investigation.
“Unfortunately it is too early to say that large doses of vitamin C could lessen the duration of a cold,” Michels tells Coach.
“The problem is that we are dealing with a large amount of inconsistent trial designs. The data is very ‘dirty’, and it makes interpretation very difficult.”
Another review by Dr Hemil? found that the incidence of colds in people under heavy physical stress, such as marathon skiers or soldiers in freezing conditions, was reduced by half when they were administered with vitamin C.
But Michels says for the average person, there’s no scientific evidence that consuming large quantities of it once you realise you’re sick with a cold will do any good.
“Timing of vitamin C during a cold is a big unknown because it’s hard to do that type of research. Most people start feeling ill long after they have been exposed to a virus, so it becomes difficult to say when a therapeutic window opens or shuts.”
Your best bet is to consume vitamin C regularly as part of a balanced diet to maintain a strong immune system, improving your chances of preventing sickness.
“Vitamin C helps to keep components of the immune system in good condition, primarily supporting the actions of white blood cells,” Michels explains. “It’s an excellent antioxidant and is very effective at reducing some types of inflammation, which probably contributes to these functions in immunity.
“It’s good to have moderately high levels in the body at all times.”
So how much vitamin C should you aim to consume every day? The Australian government recommends 45mg a day, but you can safely consume much more – Michels says up to 400mg a day has proven beneficial.
And the good news is you don’t have to eat much to hit your daily intake. An orange has approximately 70mg, a cup of strawberries has 85mg, and one green capsicum is estimated to have 95mg of vitamin C goodness.
Supplements work too, but by getting your vitamin C from fruit and vegetables you’ll also be consuming fiber and other important nutrients and minerals along with it.
Michels agrees with Dr Hemila’s recommendation that the potential benefits of vitamin C are promising and should continue to be investigated.
“We should invest more into vitamin C research, especially on the common cold, so we can better understand the power and limitations of vitamin C supplements.
“It might do a great deal, but we just don’t have the evidence for it yet.”
We can’t prove vitamin C helps a cold, but unless consumed in extreme quantities it’s not bad for you. So if you do come down with a cold, it won’t hurt to eat some extra fruit and vegetables while you’re resting up.