Vitamin C and Immunity

Is it really all that important? These days it seems there are all these much fancier vitamins; Elderberry, CoQ10 to name a few but could Vitamin C actually be more important?

Vitamin C seems to be lost in the shuffle of vitamins. We have Elderberry and CoQ10, different kinds of fish oil and Calcium Magnesium. And all of these are helpful, many of us don’t know what they do exactly, but Vitamin C is still extremely important to have in your vitamin repertoire. Humans, unlike most animals, are unable to synthesize Vitamin C endogenously, so it is an essential dietary component ^(1,2).

When transportation across the Atlantic Ocean was only possible by ship an interesting thing happened in that something called Scurvy occurred. This happens when low to no amounts of Vitamin C are consumed. People will lose teeth, their wounds won’t heal, their immune system will become compromised, gum inflammation occurs, malaise and fatigue ^{(2, 3, 4)}.

In the 1970s Linus Pauling suggested that vitamin C could successfully treat and/or prevent the common cold ^{(2, 5)}. In trials involving marathon runners, skiers, and soldiers exposed to extreme physical exercise and/or cold environments, prophylactic use of vitamin C in doses ranging from 250 mg/day to 1 g/day reduced cold incidence by 50% ⁽²⁾.

What foods are rich in vitamin C?
Table from the NIH website ⁽²⁾:

*DV = Daily Value. The U.S. Food and Drug Administration (FDA) developed DVs to help consumers compare the nutrient contents of products within the context of a total diet.

Side effects are low and rare as Vitamin C has low toxicity and is not believed to cause serious adverse effects at high intakes ⁽⁶⁾. Common complaints include diarrhea, nausea, abdominal cramps, and other gastrointestinal disturbances due to unabsorbed vitamin C in the gastrointestinal tract ^(3,6).
As with anything consulting your primary care physician is important when starting any type of new diet, exercise or other regime.

Groups more at risk for having lowered amounts of Vitamin C include smokers due to the increase of oxidative stress, infants fed evaporated milk or boiled milk, individuals with limited food variety such as the poor and children ⁽²⁾. Those with intestinal malabsorption issues and cancer patients also have a higher risk of Vitamin C inadequacy ⁽²⁾.

References:

1. Li Y, Schellhorn HE. New developments and novel therapeutic perspectives for vitamin C. J Nutr 2007;137:2171-84.
2. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/#en1 Opens in new window
3. Jacob RA, Sotoudeh G. Vitamin C function and status in chronic disease. Nutr Clin Care 2002;5:66-74. [PubMed abstract Opens in new window]
4. Francescone MA, Levitt J. Scurvy masquerading as leukocytoclastic vasculitis: a case report and review of the literature. Cutis 2005;76:261-6.
5. Pauling L. The significance of the evidence about ascorbic acid and the common cold. Proc Natl Acad Sci U S A 1971;68:2678-81.
6. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids Opens in new window. Washington, DC: National Academy Press, 2000.