For colds, most people reach for vitamin C to help them get back on their feet sooner. They might chose it because they can tell it helps them feel better, or they might have heard about one of the numerous studies supporting its use. Most studies show that vitamin C reduces the severity of cold symptoms. Even one famous “negative “ study showed that vitamin C reduced the severity of cold symptoms by 20%. This was only considered a negative outcome because these results were not deemed significant. Other studies show that vitamin C accelerates recovery, especially if taken early in the illness. One study using 3000-6000 mg daily showed an 85% reduction in cold and flu symptoms compared to the control. I notice that especially toward the end of a cold, taking vitamin C has a marked effect on my energy levels, helping me get back to work.
Vitamin C can be beneficial for other respiratory issues. In epidemiological studies, increased vitamin C intake is correlated to lower rates of asthma. Supplementation with vitamin C also has been shown to reduce exercise-induced airway reactions such as narrowing of the airways. Additionally, vitamin C may be helpful for asthma that is related to pollution. These benefits are partially due to vitamin C’s anti-histamine effects, which are augmented by the presence of bioflavonoids, compounds that occur in foods alongside vitamin C that potentiate its activity.
Vitamin C’s well-known antioxidant capabilities provide part of its protect of the respiratory tract. When we are exposed to pollutants and toxins, free radicals cause cellular damage, which in turn contributes to inflammation that can exacerbate conditions like allergies and asthma. It is probably these antioxidant actions that help me feel more energetic at the end of a cold. When the immune system is working hard it creates free radicals as part of the process, and these free radicals can contribute to fatigue. By helping remove these free radicals, vitamin C can help you feel normal again. Likewise, vitamin C can protect vital molecules in the body, such as proteins, lipids, carbohydrates, and DNA from damage by free radicals that can be generated during normal metabolism as well as through exposure to toxins. This preserves crucial cellular functions and can help prevent cancer. Finally, vitamin C can regenerate the antioxidant capacity of vitamin E, which is in turn one of the most important fat soluble antioxidant that supports heart health by preventing the oxidation of cholesterol. Again, bioflavonoids also can work as powerful antioxidants supporting the activity of vitamin C so I always look for these when I buy vitamin C.