Last time you had a cold, the chances are at some point you heard about the benefits of vitamin C and why you should take it to shorten a cold, but is this true? Can vitamin C really shorten a cold? To try to answer this question, let’s look at the science behind vitamin C.
Vitamin C, also known as L-ascorbic acid, is an essential vitamin that is not produced by your body, meaning you have to consume it through food and drinks. Vitamin C is required for your body to produce collagen, carnitine, catecholamines, and is an antioxidant. Collagen is an essential component of connective tissue, carnitine is required to transport fatty acids to the mitochondria, the cell’s energy source, and catecholamines are neurotransmitters that mediate a variety of your central nervous system functions. As an antioxidant vitamin C prevents reactive chemicals that contain oxygen from damaging other cells in your body. This may help prevent certain cancers and cardiovascular disease.
Overall, vitamin C is important for your body to function efficiently. But going back to the initial question, how does it affect our immune systems? Vitamin C may improve the absorption of iron by up to 3 fold. Iron serves as an innate immune mechanism, meaning it protects your body from pathogens for short term periods. It will kill the pathogen but it will not give you immunity to the pathogen. So more vitamin C mean more iron, and more iron means more dead pathogens, but does this really result in a shorter cold?
A Cochrane Review in 2007 tested this theory with a sample of humans and had some interesting results. They discovered for the general population, taking vitamin C does not reduce your chances of getting a cold, unless you submit your body to extreme conditions such as marathon running or extremely cold environments. For the soldiers, skiers, and runners out there, taking a vitamin C supplement can reduce your chance of acquiring a cold by as much as 50%. For the average person, you reduce your chance by only 8%. The kicker is if you wait until you get a cold to start taking vitamin C, it will not help. If vitamin C was taken after the onset of the cold it did not shorten the cold’s duration or severity of symptoms.
If you are not submitting your body to extreme environments, and that 8% reduced chance of getting a cold sounds appealing, then supplement your current diet with about 400-500 mg of vitamin C per day. Also, if you believe you are not consuming at least 300 mg of vitamin C from your normal diet then you may at risk for scurvy, so add a supplement to your diet. Some common foods that are good sources of vitamin C are red pepper, green pepper, oranges, broccoli, strawberries, kiwis, and grapefruit. If you eat enough fruits and veggies, then you shouldn’t need to supplement vitamin C. However, the toxicity of vitamin C is so low that even high doses will leave you unharmed.
In summary, if you consistently get enough vitamin C, you may be able to reduce your chances of getting a cold. If you start taking vitamin C after you get a cold, it will not reduce the duration or the severity of the cold.