Myths busted: Does vitamin C really prevent colds?


You might be tempted to reach for some vitamin C tablets or a tall glass of orange juice when the sniffles hit.

Many people use vitamin C to prevent the common cold. Vitamin C helps us absorb iron, produce collagen and maintain a healthy bone structure, immune system, muscles, and blood vessels.

There have been a number of studies into the powers of vitamin C, all with inconsistent results. So, does vitamin C really prevent colds? The experts at House Call Doctor have put together everything you need to know.

The studies

A 2013 Harvard study suggested extremely active people, such as marathon runners, may cut the risk of getting a cold in half by taking 200mg of vitamin C per day.

But, for the general population, the same amount of vitamin C won’t stop a cold. It may, however, reduce the duration of symptoms by up to one day.

Researchers suggest daily doses of around 8000mg of vitamin C may prevent a cold, but this must be weighed against the fact 2000mg of vitamin C in a day can cause nausea, diarrhoea, abdominal pain, and issues with blood sugar.

What you should do

To reduce the duration of cold symptoms, vitamin C should be consumed every day.

The recommended daily amount of vitamin C is 90mg for men and 75mg. You can achieve this by eating the recommended five servings of vegetables and two servings of fruit per day.

Supplements are a useful way to increase how much vitamin C you are consuming and strengthen your immune system generally but should not be relied upon to treat the common cold.

If you or your loved one’s cold symptoms are worrying, your GP will be able to advise the best method of treatment.