Vitamin C is required for the biological development of collagen, L-carnitine, and certain neurotransmitters; vitamin C is also involved in protein metabolism. Collagen is an essential component of connective tissue, which plays a vital role in wound healing. Vitamin C is also an important physiological antioxidant and has been shown to regenerate other antioxidants within the body. Ongoing research is examining whether vitamin C, by limiting the damaging effects of free radicals through its antioxidant activity, might help prevent or delay the development of certain cancers, cardiovascular disease, and other diseases in which oxidative stress plays a causal role
Despite the popular belief that vitamin C can cure the common cold, the scientific evidence for this is limited and conflicting. Large doses of vitamin C may help reduce the duration of a cold if you are deficient in vitamin C to begin with – which is very rare for most Americans.
The vitamin may be useful for preventing a cold if you live in very low temperature environments, or you are routinely involved in vigorous exercise such as marathon running.
Heads up though- people with kidney disease should avoid vitamin C supplements. I hope you will think about meeting your daily vitamin and mineral requirements by eating a diet rich in fruit and vegetables. Taking more than 500 mg (in pill or powder drink form) of vitamin C at any one time provides no advantage. More than that amount is simply lost through malabsorption and urination.