Vitamin C 'does not stop colds'

Taking a daily supplement of vitamin C will not protect most people from common colds, scientists say.

A review of 30 studies, involving 11,350 people, also found doses of at least 200mg per day did little to reduce the length or severity of colds.

But people exposed to periods of high stress, like marathon runners, could reduce their risk of catching colds by half if they took the vitamin daily.

The Australian and Finnish team's study is published in the Cochrane Library.