Vitamin C for colds

The common cold is…well, it’s common. It is the biggest reason in developed countries why people visit the doctor and take time off work or school. There are of course varying responses from person to person with the cold. Some souls will stoically fight on and meet all their commitments with sinuses full to exploding and a cough that will take plaster off the walls. Then there are those who at the first sign of a sniffle will fall as if they have been shot with a silver arrow between the shoulder blades. The very fact that we all experience colds is behind the variety of reactions and it is this same prevalence that means there is a wealth of research into ways to alleviate the common cold. For a long time since Nobel Prize-winning biochemist Linus Pauling published his treatise Vitamin C and the Common Cold in 1970, vitamin C has been at the centre of this research, but how effective is it?

Vitamin C has a long history in healing long before it was even known that the vitamin existed. For a long time it was known that citrus fruits like oranges, lemons and limes could prevent scurvy, which is vitamin C deficiency. Of course, in the early stages it was not known that vitamin C existed but just that citrus could prevent the dreadful symptoms of scurvy in sailors, for example. By 1907, however, researchers Axel Holst and Alfred Frohlich proposed the existence of “vitamin C”, this substance that could be made by neither guinea pigs nor humans, and the lack of which led to scurvy.

Although orange juice and lemon juice have high levels of ascorbic acid (vitamin C), however, they contain sugars that make purification of vitamin C extremely difficult. So this “vitamin C” remained unisolated until 1933, when scientist Albert Szent-Györgyi was first able to isolate the compound vitamin C in usable quantities. Szent-Györgyi managed, by deriving enough ascorbic acid from paprika made from capsicum, to make three pounds. The rest is vitamin history and for some time vitamin C has had a reputation for being able to boost immunity and help prevent colds and flu. For all those who advocate vitamin C though, there have been doubters. A new study has brought some interesting light to the issue.

The study was actually an analysis of data from 29 randomised placebo controlled trials that have been done on more than 11,000 people to establish the link between vitamin C usage and the common cold. The studies chosen for analysis used at least a dosage of 200mg of vitamin C daily.

The first finding was that, in the general population, vitamin C supplements do not prevent the common cold from occurring. It does need to be said, however, that a level of 200mg of vitamin C is below what most naturopaths would recommend as effective so this may be a confounding factor. The analysis did find that one gram of vitamin C per day does reduce the duration of the common cold by eight per cent in adults and by 18 per cent in children. The most interesting finding though was yet to come.

The results showed that vitamin C supplementation did help prevent colds in people who were under heavy physical stress such as marathon runners, cross-country skiers and soldiers on exercises. It is known that heavy physical exercise suppresses immunity so it would seem that vitamin C does have an immune-enhancing effect. This effect is perhaps not enough to prevent colds in otherwise healthy people, but enough to reduce cold duration in healthy people and to prevent colds in people who are immune compromised, like heavy exercisers.

As with most things medicinal, it comes down to dosage and whether a person needs the medicine or not. It’s not rocket science really.