Studies show that vitamin C may shorten the length of a cold by about one day, but it will not prevent cold symptoms.
What Is It?
Can Vitamin C Prevent or Treat Cold Symptoms?
There have been a lot of studies, but the findings aren’t consistent. Overall, experts find little to no benefit if you use vitamin C to prevent or treat a cold.
In 2010, researchers looked at all studies and found that taking vitamin C every day did not prevent the number of colds that a person got. In some cases it made symptoms improve. However, vitamin C didn’t help if people took it after they showed signs of getting sick.
The results were different for people who were in extremely good physical condition, such as marathon runners. People like that who took vitamin C every day cut their risk of catching a cold in half.
So what does all this mean?
If you take at least 0.2 grams of vitamin C every day, you’re not likely to have fewer colds, but they may end a day or two quicker.
Is It Safe?
In general, vitamin C won’t harm you if you get it by eating food like fruits and veggies. For most people, it’s also OK if you take supplements in the recommended amount.
Higher doses of vitamin C (greater than 2,000 milligrams per day) may cause kidney stones, nausea, and diarrhea.
Talk to your doctor if you’re thinking of taking vitamin C pills and let him know about any other dietary supplements you use.