Does Vitamin C Prevent Colds

One effect most commonly associated with vitamin C is to prevent or treat colds. Let's see what happens when patients do not know if they are taking vitamin C or a placebo ...


In the 70s, the influence of the theories of Pauling, there were 4 well-designed randomized controlled trials that administered up to 8 grams of vitamin C (Anderson 1974 in Canada,  1975 to NIH, Elwood in the UK in 1977 and Tyrell UK in 1977) [1 [2 [3 [four]. These studies were inconclusive on the use of vitamin C in the cold and were unable to make any improvement.

 Between 1999 and 2001, at the Center for Epidemiology at the National University of Australia in Canberra, in a randomized, placebo-controlled clinical trial, they administered mega doses of vitamin C (1 and 3 grams) or a compound called Bio-C (vitamin C 3 g, bioflavonoid 75 mg, 150 mg rutin, hesperidins 150 mg, 750 mg rosehips and areola 150 mg) to 400 volunteers for 18 months. The placebo consisted of 0.03 grams of vitamin C. [5] Data evaluated were severity, duration and doctor visits. Results: like in older studies, there were no major differences in terms of severity, duration or number of doctor visits during the year and means of monitoring the study volunteers.

 A Cochrane review (meta-analysis with strict methodology) 30 controlled clinical trials found that vitamin C does not prevent colds or improve the severity of them. However, once established, there is a modest but clear reduction in days with symptoms, decreasing them an 8 or 9% on average (0.45 days in cold, ie, about 10 hours less of symptoms). Not much, but it's something, of 5 days on average that can last a cold we will be only four days and a half experiencing symptoms.

 [6] Conclusions Vitamin C does not prevent in any way the cold. Nor reduces the severity or symptoms of it. However, you can make the duration of symptoms once set a little lower. Specifically least noon. Therefore it is useless to take supplements of vitamin C throughout the year to try to prevent colds, but can be useful once established. Some drugs typically incorporate, as Fernando, the Propaganda Plus ... although always best whole fresh fruit like kiwi, orange, papaya, pineapple, grapefruit, raspberries!