How Vitamin C and D Promote a Proper Immune Response Against Viruses


Spread of the novel coronavirus that began in late 2019 in Wuhan province of China has long turned into a global pandemic according to the World Health Organization. It was in February 2020 when the first cases where reported in California. Currently there are at least 13,816 cases and 617 deaths in Los Angeles County. There are now 60 deaths in San Bernardino County and 1,406 cases reported. Actual numbers are far greater since these figures don’t include individuals who have not sought medical attention or those with the infection but not showing symptoms. With epidemiologist all but guarantying the situation will worsen in southern California, we need to brace for a surge in cases.

Since we lack wide-spread testing and a vaccine; it is critical to take measures to strengthen our immune system in case of a coronavirus exposure. I encourage everyone to take advantage of simple, validated measures to boost general immunity using vitamin C and vitamin D. In the next few paragraphs, I detail just some of what researchers have uncovered regarding vitamins C and D’s role in coronavirus, pneumonia and immunity. In addition, a whole food, anti-inflammatory diet, rich in antioxidants and the above-mentioned vitamins could minimize the severity of coronavirus infections in those exposed. These measures are important for all individuals yet, critical in older adults and individuals with a preexisting disease.

Vitamin C and Immunity

Evidence from early animal and human trials find that low vitamin C intake may increase the susceptibility to and the severity of infections.1 According to a 2000 Food and Nutrition Board report, the average daily vitamin C intake in the U.S. is only 100mg while up to 10 percent of the population consumes a measly 4mg or less daily. Eating either a large orange, a green chili pepper, 1/3rd cup of sweet yellow pepper or a large kiwi each would supply approximately 100mg of vitamin C. Vitamin C’s role in treating and preventing infections is largely via immune system support. White blood cells (WBC), our major defense against microbes, contain vitamin C levels that are 10 times greater than the amount found in the surrounding plasma.2 This explains in part why research on vitamin C show it affects the function of a type of WBC known as phagocytes, specialized cells that ingest microbes.2 Vitamin C also supports the maturation of T-lymphocytes, a type of specialized WBC that works in concert with the phagocytes and is important in cell-mediated immunity.3 Cell-mediated immunity is crucial for the destruction of microbes in the body. Also, studies show vitamin C enhances production of interferon, a messenger protein important for the activation of other parts of the immune system and that also interferes with viral replication.4,5

Vitamin C and Pneumonia

Vitamin C deficiency has been associated with an increased risk of pneumonia. Early U.S. and German physicians hypothesized and published papers based on their observations. There are at least three controlled trials and two controlled trials that show that vitamin C prevented pneumonia and benefited patients with pneumonia respectively.6 A Cochran review reported three vitamin C studies, each showing that the incidence of pneumonia was 80 percent lower in those receiving vitamin C.6,7

Antioxidative Effects of Vitamin C in Infections

Oxidative damage caused by free radicals is a normal part of many processes in the body. For example, oxidation occurs during metabolism, detoxification and even during exercise. During an infection, our immune system relies, impart, on oxidative damage to attack and deactivate pathogens like viruses.8 Vitamin C appears to protect human cells from the oxidative damage caused by phagocytes, while not interfering with the anti-pathogenic effect of oxidation. Animal models have shown that vitamin C deficiency is associated with greater lung pathology in influenza and that Influenza results in less vitamin C in lung fluid.9,10 One of the most ominous complication of viruses that infect the lungs is pneumonia. This is especially so with the coronavirus. Those with the most severe outcome suffer excessive oxidative damage and inflammation of immune cells and lung tissue. The resulting swelling and thick, proteinaceous fluid retention prevents adequate oxygen and carbon dioxide exchange in the lungs. Vitamin C reduces oxidative damage and inflammation, allowing the immune system to effectively neutralize pathogens like the coronavirus and reducing the chances of compromised breathing. Other nutritional antioxidants likely play a similar role.

IV Vitamin C Used in COVID-19 Patients

A handful of prominent medical researchers from China, the U.S. and Japan began two separate clinical trials on the effects of intravenous vitamin C and COVID-19 in China this past February 2020.11 The “Expert Group on Clinical Treatment of New Coronavirus Disease in Shanghai” describes the successful additive use of IV-C in COVID-19 hospitalized patients.12 Their clinical trial draws the conclusion that the inclusion of IV-C improved survival and shortened hospital stays. This study further broadens work showing IV-C improved survival in hospitalized patients with sepsis and acute respiratory distress syndrome (ARDS).13 IV-C also reduced hospitalization and reduced the need for ventilation in those patients.13 These findings are remarkable considering the low survival rate of sepsis and ARDS.

Vitamin D, Immunity and Viral Infections

Thanks in part to John Cannell, MD, leading researcher on vitamin D; we know of vitamin D’s integral role in immune system function. He conducted clinical trials on hospitals patients, comparing the incidence of influenza in those receiving vitamin D with those not receiving it. He recognized that the influenza virus spread more rapidly in those with inadequate vitamin D status. Vitamin D has since been determined to increase the production of up to 300 different antimicrobial proteins called peptides, and to prevent the over expression of inflammatory mediators. One antiviral peptide supported by vitamin D and known as defensins is activated by the binding of vitamin D to the vitamin D receptor. Defensins then acts to disrupt the viral membrane and interfere with viral replication. In order to participate in an immune response, T-cells must first be activated.14,15 Researchers from the University of Copenhagen determined that T-cell activation is dependent upon vitamin D.

A balanced and effective immune response relies not only on a nutritious, whole foods, anti-inflammatory and antioxidant rich diet, but also requires optimal amounts of vitamin C and vitamin D. Other nutritional based antioxidants likely play a similar role, activating components of the immune system required for the neutralization of pathogens, and insuring the inflammatory and oxidative response is balanced to not compromise oxygenation or damage lung tissue. These sensible measures can minimize the severity of coronavirus and other infectious diseases in those exposed. I believe these measures are important for all individuals, yet critical in older adults and those with a preexisting disease.

Dr. Ayo Bankole, ND, PA is a licensed Naturopathic Doctor treating individuals with heart disease, cancer and other environmental and lifestyle related conditions. He also possesses advanced training in environmental medicine and uses IV nutritional therapy, detoxification, and chelation therapy as appropriate.

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