An immune system capable of withstanding infection and illnesses is our greatest line of defense against infection and illness, but like any fighting force it requires proper nutrition to remain effective.

Vitamin C in its ascorbic acid form is an extremely potent antioxidant that can scavenge free radicals and protect cells, tissues and organs from damage. Furthermore, ascorbic acid promotes anti-inflammatory cytokine production as well.

Increases Immune Function

Vitamin C is an indispensable water-soluble dietary vitamin that plays a pivotal role in supporting normal immune system function. It acts as both an integral cofactor in biosynthesis processes, and as a powerful antioxidant – protecting cells against free radical damage from oxygen exposure. Furthermore, vitamin C enhances epithelial barrier function against pathogens while also aiding neutrophils’ antioxidation capabilities – key innate immune cells with powerful antioxidation capabilities.

Studies indicate that vitamin C enhances both neutrophil phagocytosis and killing of bacteria by stabilizing microtubules [1, 2] as well as increasing production of reactive oxygen species (ROS) [3, 4]. Vitamin C may also induce neutrophils to commit apoptosis after taking up microbes and aids macrophages in clearing away their dead cells from infection sites more efficiently thereby limiting tissue damage.

Chronic Granulomatous Disease (CGD), Chediak-Higashi Syndrome (CHS), and Atypical Hemolytic Uremic Syndrome have all been associated with reduced neutrophil functions; vitamin C supplementation was found to improve leukocyte chemotaxis. Furthermore, oral administration of 400 mg of oral vitamin C twice daily during sepsis increased serum haptoglobins levels significantly while significantly decreasing mortality [14].

Immune cells respond to various stimuli by producing cytokines that regulate their migration, phagocytic, and apoptotic responses. Vitamin C has been demonstrated to modulate proinflammatory cytokines such as IL-1 and TNF-a in vitro by either modulating redox-sensitive signaling pathways or directly stabilizing key cell structural proteins. Vitamin C has also been found to initiate the apoptotic process by attenuating activation of caspases enzymes involved in phosphatidyl serine release leading to neutrophil death thus reducing inflammation and tissue damage while decreasing inflammation and tissue damage overall.

Vitamin C’s other immunomodulatory effects include its ability to stimulate lymphocyte proliferation and cytokine production in response to immunization, and raise antibody levels after vaccination. Yogurt, cheese, and nuts provide essential immune-boosting support through Vitamin C as well as other essential vitamins and minerals such as protein, fiber, healthy fats, phytochemicals and phytochemicals; additionally they contain high concentrations of Vitamin E which supports immune cells by protecting them and helping them work more effectively.

Reduces Inflammation

Ascorbate, the reduced form of vitamin C, is a generous donor of electrons which can effectively counteract free radicals found within cells and protect body tissues by decreasing endogenously generated oxidative stress as well as replenishing other antioxidants such as glutathione, alpha lipoic acid and vitamins (and even certain metals like copper and zinc). Ascorbate’s protective capabilities include helping the body ward off damage through reduction of endogenously generated stress as well as replenishing other antioxidants like glutathione, alpha lipoic acid and vitamins (and even metals like copper & zinc).

Vitamin C’s antioxidant properties aside, its direct impact upon immune cells lies within their innate and adaptive immune functions is quite direct. Human neutrophils – an integral component of the innate immune system – accumulate greater concentrations of vitamin C than what can be found in plasma (up to 100 times more!) during oxidative bursts indicating this micronutrient’s necessity for optimal leukocyte functioning [17].

Vitamin C administration has been shown to decrease inflammation responses following exposure to extreme physical stress and cold temperature, according to studies in humans. For instance, one subgroup of six studies concluded that supplementing marathon runners and skiers with Vitamin C supplementation significantly decreased signs of acute immunosuppression by an average of 50%.

Other innate immune system cells, including macrophages and microglia, also appear to require vitamin C for optimal functioning. Treatment with vitamin C resulted in reduced activation and production of pro-inflammatory cytokines IL-6, IL-1, and TNF- following LPS stimulation in vitro; similarly treating microglia with vitamin C resulted in decreased inflammation responses when challenged with bacteria LPS in vivo.

T- and B lymphocytes that comprise the adaptive immune system require physiological levels of vitamin C in their incubation medium for optimal functioning, as this has been demonstrated to increase B-cell proliferation and antibody production dose-dependently [19].

Vitamin C’s multiple beneficial effects may be attributable to its ability to donate electrons as cofactors for various biosynthetic and gene regulatory enzymes, thus altering cellular function within both innate and adaptive immune cells. Furthermore, as an antioxidative water-soluble vitamin that can scavenge free radicals and regenerate other antioxidants directly or indirectly protecting both systems against damage caused by oxidation.

Relieves Cold Symptoms

Vitamin C can be taken in high doses without adverse side effects, yet its best effect lies in combination with other immune-enhancing nutrients like zinc and vitamin D. Together these help the body build resistance against disease while healing more quickly.

Vitamin C supplements won’t prevent most people from contracting the common cold, but may shorten its symptoms by up to one or two days. Beginning a regimen once sick is likely not going to significantly shorten your illness either.

Studies on vitamin C’s effects on cold duration and severity have provided us with evidence of its efficacy in shortening its length by lessening symptoms such as runny nose, sore throat or headache. According to this research, vitamin C can substantially shorten its length – for instance shortening runny nose duration by cutting severity in half or shortening runny nose duration by half or shortening duration of headache by one third or more!

There is evidence to support its ability to protect those at a higher risk from upper respiratory tract infections (URTIs) through prophylactic use, likely because vitamin C’s ability to enhance white blood cell count helps ward off infection.

Vitamin C has long been recognized for its ability to shorten the duration of a common cold when taken at its initial sign, possibly because it helps restore natural defense mechanisms by increasing energy production and lowering inflammation levels.

Vitamin C can shorten the duration of a cold by increasing zinc absorption rates, which have been found to hasten recovery from common colds. To get maximum benefit from this interaction, it’s important that zinc be taken in its chelated form instead of citrate or gluconate which bind to vitamin C and reduce its absorption.

Diets rich in fruits and vegetables offer more than just vitamin C; they’re also packed with essential vitamins and minerals essential to maintaining an immune system in good condition. Try including more foods such as berries, tomatoes, green and red bell peppers, broccoli and kiwi into your daily routine to bolster it further.

Prevents Cancer

Vitamin C is an abundant, water-soluble molecule with powerful antioxidant and immune-enhancing properties, as well as being essential in many biosynthetic and gene regulatory processes. Furthermore, it can scavenge free radicals while simultaneously decreasing toxic nitrogen-based compounds like N-nitrosamines and nitrosoureas that are known carcinogens and impair normal tissue functioning.

Vitamin C supports both innate and adaptive immune cells by producing immunoglobulins (Igs), antibodies-based proteins which combat infection. Furthermore, evidence indicates that MnSOD regulates T cells and B lymphocytes by directly increasing their proliferation, cell surface expression of Igs, secretory activity, as well as modulating cytokine responses. Supplementation with vitamin C has been demonstrated to enhance production of anti-inflammatory cytokines IL-10 and IL-1a by peripheral blood mononuclear cells after LPS stimulation, while simultaneously decreasing TNF and IL-6 production from microglia – resident myeloid cells of the central nervous system – following LPS exposure.

Vitamin C also improves neutrophil migration to sites of infection, phagocytosis and oxidant generation, microbial killing, as well as tissue repair by protecting oxidant-sensitive caspases activated during neutrophil apoptosis, thus decreasing excessive tissue damage and supporting resolution of inflammation. It has even been demonstrated to enhance leukocyte chemotaxis in individuals suffering from genetic disorders of neutrophil function such as chronic granulomatous disease or Chediak-Higashi syndrome.

Vitamin C has also been demonstrated in various clinical and experimental studies to be an effective cancer preventative agent, by inhibiting tumor growth, curbing metastasis spread, and curbing angiogenesis and angioma formation. Cancer researchers believe it may help prolong remission for some forms of cancer by making radiation and chemotherapy treatments more efficient. However, most human studies – including the FDA approval trials that led to Gleevec’s approval – involve people receiving high doses of vitamin C via diet or supplements alone; such studies have not consistently demonstrated reduced cancer risks or mortality indicating more substantial effort is necessary in order to realize its benefits.