Vitamin C (L-ascorbic acid)
Adequate intake of micronutrients is required for the efficient function of the immune system. Deficiency in vital micronutrients, specifically vitamin C, suppresses immunity by affecting immune responses to a myriad of bacterial and viral infections. Data has shown that supplementation with Vitamin C results in improvement in several components of the immune system such as anti-microbicidal and killer (NK) cell activities, lymphocyte proliferation and chemotaxis (cell movement) of immune cells. In the figure(s) below, panel A demonstrates that the survival rate(%) of wr (wildtype), Gulo (-/-),and Gulo (-/-)+VC is identical after 8 days when not exposed to the influenza A virus (H3N2). Wildtype mice are without genetic modification. Gulo (-/-)are genetic knockout mice that lack L-gulono-Y-Iactone oxidase (gene) for the endogenous production of vitamin C. Gulo (-/-)+VC are mice that lack L-gulono-Y-Iactone oxidase (gene) but received vitamin C supplementation. As shown in Panel B, the survival rate after 8 days was severely compromised in Gulo (-/-)/influenza A (H3N2) virally infected mice that did not receive vitamin C supplementation. This data demonstrates that a deficiency in vitamin C may increase mortality and/or severity of influenza virus infection in humans, whereas, adequate vitamin C supplementation provides for a robust immune response to the influenza virus infection (1).
No infection (N=10)
Influenza A virus infection (N=10)
Figure 1. Increase of mortality of vitamin C-insufcient Gulo (-/-) mice by the infection of inuenza A virus. Twenty hemagglutination units (HAU) of inuenza A virus (H3N2/ 1/68/HongKong) was intranasally inoculated into wild type (n=10), vitamin C-sufcient Gulo (-/-) mice (n=10) and vitamin C-insufcient Gulo (-/-) mice (n=10). And then the survival of mice was monitored for 7 days after virus inoculation. (A) Mice without H3N2 infection, (B) Mice with 20 HAU of H3N2 infection (1)
Larch arabinogalactan, is composed of greater than 98-percent arabinogalactan, a highly branched polysaccharide which has proven to be an excellent source of dietary fiber (FDA approved), a potent immunomodulator, and has shown to increase beneficial intestinal microflora (prebiotic). The immune-en hancing properties of arabinogalactan suggest an array of clinical uses, both in preventive medicine, due to its ability to build a more responsive immune system, and in clinical medicine, as a therapeutic agent in conditions associated with lowered immune function, decreased killer (NK) activity, or chronic viral infection. Recent data (2013) demonstrated that incidences of the common cold were reduced over a12-week period following supplementation with arabinogalactan attributed to increased immune system responsiveness. Figure 2 demonstrates that in FAS (Full Analysis Set) and PP (per protocol) groups that the incidence of the common cold was much lower with larch arabinogalactan supplementation versus placebo over a period of 12 weeks (2).
Figure 2. Incidence of common cold infections following 12 week arabinogalactan or placebo supplementation according to the FAS and the PP population. Values are mean ± SD (2).
1. Kim Y., Kim H., Bae S., Choi J., Lim S.Y., Lee N., Kong J.M., Hwang Y., Kang J.S., and Lee W.J. Vitamin C is an Essential Factor on the Anti-viral Immune Responses through the Production of Interferon a/ß at the Initial State of Inuenza A Virus (H3N2) Infection. Immune Network. Vol. 13, No. 2; 70-74, April, 2013 2. Riede L., Grube B., and Gruenwald J. Larch arabinogalactan effects on reducing incidence of upper respiratory infections. Current Medical Research and Opinion. 2013. 29:3, 251-258.