Understanding the Role of Vitamin C in Immune Health and Disease Prevention3 min read
Vitamin C (ascorbic acid) is an essential nutrient needed to build blood vessels, cartilage and muscles. Furthermore, its powerful antioxidant properties help the body absorb iron efficiently.
Studies of prospective cohort groups have demonstrated that people with high vitamin C levels in their blood have a reduced risk of heart disease and cancer.
Vitamin C is an Antioxidant
Vitamin C (L-ascorbic acid) is a water-soluble micronutrient that serves as one of the most potent reducing agents and free radical scavengers in biological systems. It provides first line protection from oxidative damage for membranes and proteins while acting as an enzyme cofactor during posttranslational hydroxylation of collagen, carnitine biosynthesis, peptide amidation processes and the conversion of dopamine to norepinephrine production.
Antioxidants play an integral part in protecting against diseases like atherosclerosis and cancer by neutralizing oxidant molecules that damage lipids, proteins and DNA. Studies indicate that individuals who consume more fruits and vegetables have reduced risks for various health conditions including heart disease and cancer.
As it can be hard to assess whether the positive effects of eating foods rich in vitamin C are solely attributable to its antioxidant effects, intervention trials that have examined whether supplementing with vitamin C would benefit disease have generally failed to demonstrate any improvement.
It Stimulates Interferon Production
The immune system is an intricate defensive mechanism designed to detect and destroy pathogenic microbes that pose threats, while simultaneously repairing any damage they have done. Vitamin C plays an integral part in this defense mechanism by improving epithelial barrier function, increasing white blood cell migration to infected sites, killing microbes through phagocytosis, and increasing antibody production (Figure 1).
Leukocytes stimulated to produce interferons by viruses are stimulated to release them as antiviral cytokines that serve to combat viral infection. Vitamin C boosts interferon production from phagocytes, enhances leukocyte chemotactic response and boosts proliferation and differentiation of B/T lymphocytes.
Vitamin C not only has direct antiviral properties of interferons but can also increase production of gamma-interferon which acts to inhibit viral replication. Studies on guinea pigs with human herpesvirus revealed that supplementing their diets with extra Vitamin C reduced viral particles in their lungs and serum, as well as increasing serum IFN-a titers . 
It Stimulates Natural Killer Cells
Natural killer cells (NK cells) are key players in cell-mediated immune response and Vitamin C can help promote their activity to protect against pathogens that invade.
Vitamin C has also been demonstrated to protect leukocytes from self-induced oxidative damage and increase interferon production, helping prevent diseases through stopping viral replication within the body.
Vitamin C’s effect is doubled when taken as part of an immune response; it promotes the production of nitrogen oxide within phagocytes to kill pathogens quickly and stimulate T lymphocyte production – both key components for cell-mediated immunity responses.
Vitamin C is a water-soluble nutrient found in food or supplement form that provides incredible health benefits. Vitamin C should be considered an essential nutrient in our diets to protect us against disease and maintain optimal wellbeing. A higher intake may even help prevent diseases.
It Helps the Body Absorb Iron
The body needs iron for proper functioning and to produce hemoglobin, a protein found in red blood cells that transports oxygen throughout. Animal products like beef, pork, chicken and shellfish provide ample sources of iron while vitamin C enhances absorption by creating an acidic environment in the stomach that facilitates digesting food or supplements that contain iron; additionally it assists with absorption of non-heme iron found in plants (1)
Accumulating adequate iron intake is vitally important, but pregnant women are especially at risk from iron deficiency anemia, which may negatively impact infant brain development. People living with chronic kidney disease may need to increase their iron consumption as well. Vitamin C appears to protect against cardiovascular diseases like stroke by protecting LDL cholesterol against damage while decreasing oxidative stress on low-density lipoprotein cholesterol molecules.