For years people have claimed that vitamin C will cure the common cold. There has also been speculation that it can shorten or prevent colds as well. So what does the evidence show?
A lot of research has been done on the effect of vitamin C on colds and the evidence is not exactly clear-cut. Some studies have shown positive results while others have not, but the overall consensus is that there is no proof that vitamin C will prevent or cure a cold. Some people who get the recommended about of vitamin C on a regular basis may experience a slightly shorter duration if they get a cold, but there is no evidence that it will prevent colds in the first place. It also doesn't appear to be helpful if you start taking vitamin C when you start to experience cold symptoms if you don't take it on a regular basis.
Those who seem to benefit most from increased amounts of vitamin C are people who have a vitamin C deficiency and highly trained athletes and military personnel. The studies performed on athletes and military personnel who are in very good physical shape and experience extreme conditions showed that taking vitamin C reduced their risk of catching a cold by 50%. However, these results have not been duplicated for the general public.
If you want to take vitamin C to help your immune system, it is best to get it through your diet instead of supplements. Foods high in vitamin C include:
- Citrus fruits and juices
- Green and red peppers
- Dark leafy greens
- Sweet and white potatoes
- Raspberries, blueberries and cranberries
- Brussels Sprouts
The recommended daily values of vitamin C for adult males is 90 mg/day and for adult females is 75 mg/day. Taking more than 500 mg at one time will not provide any benefit, because the body cannot store it. Also, anyone with kidney disease should avoid vitamin C supplements. Excessive amounts of vitamin C can cause upset stomach and diarrhea.
The Bottom Line
Vitamin C probably won’t help you avoid a cold, but eating a diet that includes foods high in vitamin C is good for your body because it does help boost your immune system and aids in the absorption of iron. So grab an orange and enjoy, just don't be surprised if you still get a cold.
”Vitamin C.” Medline Plus 01 Dec 08. National Institutes of Health. 13 Dec 08.
”Vitamin C and colds.” Medline Plus 15 May 12. National Institutes of Health. 09 Aug 12.
"Common Cold." Medline Plus 8 Jan 12. National Institutes of Health. 09 Aug 12.