Vitamin C and Infections

Abstract

In the early literature, vitamin C deficiency was associated with pneumonia. After its identification, a number of studies investigated the effects of vitamin C on diverse infections. A total of 148 animal studies indicated that vitamin C may alleviate or prevent infections caused by bacteria, viruses, and protozoa. The most extensively studied human infection is the common cold. Vitamin C administration does not decrease the average incidence of colds in the general population, yet it halved the number of colds in physically active people. Regularly administered vitamin C has shortened the duration of colds, indicating a biological effect. However, the role of vitamin C in common cold treatment is unclear. Two controlled trials found a statistically significant dose–response, for the duration of common cold symptoms, with up to 6–8 g/day of vitamin C. Thus, the negative findings of some therapeutic common cold studies might be explained by the low doses of 3–4 g/day of vitamin C. Three controlled trials found that vitamin C prevented pneumonia. Two controlled trials found a treatment benefit of vitamin C for pneumonia patients. One controlled trial reported treatment benefits for tetanus patients. The effects of vitamin C against infections should be investigated further.

Vitamins C, D and Zinc: Synergistic Roles in Immune Function and Infections

“…A comprehensive overview of vitamin C and infections has been recently published by Hemilä [8] who carefully evaluated the totality of the vitamin C literature including next to new publications also older papers as well as experimental data. From a large series of animal studies Hemilä concludes that vitamin C plays a role in preventing, shortening and alleviating diverse infections beyond cold and respiratory tract infections.…”

“…Temperature changes: Vitamin C has been reported to have beneficial effects on resistance and acclimatization to cold and hot environments [8,103]. Low temperatures weaken the immune response [8] and increase the risk of infections.…”

“…Low temperatures weaken the immune response [8] and increase the risk of infections. Studies have reported that prolonged exposure of the body surface to cold temperatures (cold baths, cold air, wet clothes, drafts, etc.)…”

“…Vitamin C is a cofactor for several enzymes involved in the biosynthesis of collagen, carnitine, and neurotransmitters; it's a water-soluble antioxidant and enhances gastrointestinal absorption of dietary non-heme iron. Marginal deficiency results in fatigue, lack of well-being, poor concentration whereas severe deficiency will cause weakening of collagenous structures, causing tooth loss, joint pains, bone and connective tissue disorders (e.g., impaired bone growth and disturbed ossification), poor wound healing and a compromised overall immunity [2,8]. Vitamin D (calciferol) is a fat-soluble vitamin.…”

Protective Activity of Ascorbic Acid at Influenza Infection

“…Indeed, in addition to the described symptoms, patients suffer from wound healing disorders and other pathologies that can be explained from this point of view. Therefore, the role of vitamin C was mainly, if not exclusively, attributed to the maintenance of the integrity of the connective tissue, despite numerous observations of the effect of AA on the course of infectious processes as well [25].…”