Vitamin C

Vitamin C affects your immune health in several ways.

Its antioxidant activity can decrease inflammation, which may help improve your immune function

Vitamin C also keeps your skin healthy by boosting collagen production, helping the skin serve as a functional barrier to keep harmful compounds from entering your body. Vitamin C in the skin can also promote wound healing (1Trusted Source).

The vitamin also boosts the activity of phagocytes, immune cells that can “swallow” harmful bacteria and other particles (1Trusted Source).

In addition, it promotes the growth and spread of lymphocytes, a type of immune cell that increases your circulating antibodies, proteins that can attack foreign or harmful substances in your blood (1Trusted Source).

In studies of its effectiveness against viruses that cause the common cold, vitamin C doesn’t appear to make you any less likely to get a cold — but it may help you get over a cold faster and make the symptoms less severe (6Trusted Source).

There’s also some evidence from animal research and case studies in humans that high dose or IV vitamin C can reduce lung inflammation in severe respiratory illnesses caused by H1N1 (“swine flu”) or other viruses (7Trusted Source, 8Trusted Source, 9Trusted Source).

However, these doses were far above the DV, and there’s not enough research to support the use of high dose vitamin C for lung inflammation at this time. You shouldn’t take high doses of vitamin C supplements — even orally — because they can cause side effects like diarrhea (2).

Summary

Vitamin C is an important nutrient found in fruit and vegetables that may help shorten the duration and severity of colds. High doses are being studied for their potential to decrease lung inflammation, but more research is needed.vitamin C benefit