Vitamin C has many important functions in key areas of the body, including:
- As an antioxidant, controlling free radical damage to cells
- Enhancing immune system response
- Maintaining integrity of blood vessels and connective tissue
- As an essential nutrient for healthy adrenal gland function
- Anti-histamine and anti-inflammatory actions
Vitamin C performs so many direct and indirect actions in humans that a deficiency has extremely wide ranging implications.
The other unusual and remarkable quality of vitamin C is that it is extremely safe. Your body adjusts its Vitamin C absorption according to need, so a person in good health will absorb much less than someone requiring therapeutic amounts to treat a poorly functioning system. Any dietary excess is excreted via the kidneys and in large supplement doses the unabsorbed excess is flushed out via the lower bowel in a moderate form of diarrhea – a short term balancing mechanism.
Vitamin C helps to repair and regenerate tissues, protect against heart disease, aids in the absorption of iron, prevents scurvy, and decreases total and LDL (“bad”) cholesterol and triglycerides. Research indicates that vitamin C helps protect against a variety of harmful free radicals, and helps neutralize the effects of nitrites (preservatives found in some packaged foods that may raise the risk of certain health problems). Supplemental Vitamin C may also lessen the duration and symptoms of a common cold; help delay or prevent cataracts; and support healthy immune function.
In our often stressful and heavily polluting industrialized world our need for effective antioxidants is universal. Vitamin C is the body’s primary water soluble antioxidant, working synergistically with other antioxidants to reduce free radical destruction. Vitamin C’s roles both in collagen production and as an antioxidant help to preserve cellular and tissue integrity and reduce damage that leads to disease.
Vitamin C’s importance to healthy immune function has been established since studies in the early 1970’s revealed that lymphocyte function and antibody production substantially improves with increased Vitamin C uptake.
Further research has focused on specific key elements of the body’s defense system, the IgA and IgM antibodies and complement protein C3. These all show increased serum levels from Vitamin C supplementation, enhancing and strengthening the immunological response. Production of interferon, an antiviral and anticancer agent, is another function of Vitamin C.
Toxins released by infections cause a depletion of Vitamin C in all tissues. The extreme effect of this in uncontrolled infection is acute scurvy, where blood vessels lose integrity due to collagen depletion and bleed out causing death. Vitamin C is administered intravenously or intramuscularly in large therapeutic doses as intensive treatment for many highly infectious diseases. It neutralizes all toxins, from snakebites and poisonous mushrooms to drug overdose, heavy metal toxicity and radiation poisoning.
Despite a wealth of supportive evidence, debate continues on the hot topic of whether Vitamin C is an effective remedy for the common cold, as proposed by Nobel Prize winner Linus Pauling in the 1970s. While sceptics demand conclusive evidence, the obvious immune boosting properties of Vitamin C support its beneficial action in prevention and mitigation of cold infections as well as any other biological challenges to the immune system.
Studies clearly show that our ability to resist and repel infection is mediated by effective levels of Vitamin C absorption. The greatly improved cellular absorption now possible with liposomal Vitamin C supplements gives researchers the opportunity to extend clinical studies to the next level.
The anti-inflammatory action of Vitamin C, both internally and topically, is well documented. This action is enhanced in combination with other nutrients such as Vitamin E and the bioflavonoid quercitin. Conversely, inflammatory states deplete Vitamin C, and Vitamin C deficiency increases inflammation.
Adrenal gland function and your ability to respond to stress are reliant on adequate Vitamin C intake. The highest concentrations of Vitamin C in the body are in the adrenals, eyes and brain. It is so essential to your adrenals that adrenal hormone production cannot continue without it.
Vitamin C is important in managing cholesterol metabolism and preventing atherosclerosis. Cholesterol and lipoprotein build-up in artery walls (known as plaques) is the body’s response to damaged arterial tissue, rather than simply a consequence of high dietary cholesterol. Maintaining adequate Vitamin C levels ensures a healthy supply of collagen and other factors needed for arterial wall integrity, so plaquing is unnecessary. As well as inhibiting cholesterol uptake, Vitamin C also increases the release of arterial cholesterol and facilitates its transfer out of the blood. Vitamin C also increases levels of HDL (healthy lipids) and lowers triglyceride levels, important factors in cardiac health. Research shows that Vitamin C can help dilate blood vessels and reduce high blood pressure (hypertension) in cases of atherosclerosis.
All of these factors have an impact on the health of the cardiovascular system and studies have shown positive results of increased Vitamin C intake in prevention of angina, lowering heart damage after bypass surgery, reducing the rate of re-narrowing arteries after angioplasty, reducing cardiovascular symptoms and improving ECG outcomes post heart attack (in conjunction with vitamin E). Low Vitamin C intake has also been linked with high fibrinogen, a high risk factor in strokes.
Other important roles for Vitamin C include:
- Production of thyroid hormone
- Synthesizing neurotransmitters, the chemical messengers of the body
- Metabolism of folateand some amino acids
- Enhancing calcium absorption
- Enhancing iron absorptionand preventing iron anemia when taken concurrently with either a food or supplement source of iron. (If you suspect your iron level is low get a blood test as taking iron supplements unnecessarily can raise your levels too high.)
Cigarette smoking is a Vitamin C antagonist, so smokers need twice the normal daily intake of Vitamin C to maintain adequate plasma levels. Smoking severely depletes the body’s Vitamin C levels and at the same time the need for Vitamin C increases due to the increased oxidative burden plus the restricted blood flow caused by smoking. Extra Vitamin C is also needed to address the high incidence of periodontal disease (and its link to atherosclerosis) among smokers. It can also help slow down the premature skin wrinkling typical in long term smokers.
- Alcoholism and eating disorders increase the risk of deficiency.
- Restrictive diets, food fads and diets high in junk food are all risk factors. Elderly people forgoing prepared meals for a mainly tea-and-toast diet risk deficiency.
- Infants bottle fed on cow’s milk instead of breast milk during their first year are at risk.
- Pregnant and breastfeeding women have a higher intake requirement for Vitamin C, having an increased utilization rate.
- Refugees are another sector of the population at risk, relying on food parcels and with poor access to fresh produce.
- Increased and ongoing exposure to stress or cold and recurring infections all increase the risk of deficiency.
- Lead toxicity indicates a need for Vitamin C and studies show intake of at least 1000 mg daily significantly decreases blood lead levels.
- Gout sufferers tend to have low vitamin C intake and can reduce their uric acid levels and risk of gout by taking Vitamin C supplements.
- People on kidney dialysis and those with thyrotoxicosis require increased Vitamin C intake and are therefore at risk of deficiency.
- Diseases of the small intestine such as Crohn’s and celiac increase the risk of Vitamin C deficiency because this is the site of absorption.
- Hemochromatosis (an iron overload disorder) is another risk factor, as excess iron antagonisesVitamin C. However Vitamin C aids iron absorption so caution is needed in this case.
- Dental infections from cavities, root canals and periodontal disease; mercury toxicity from leaking amalgam fillings and a lowered immune system from implants all have such a negative impact on antioxidant levels they are implicated as a leading cause of heart disease and cancers. Therapeutic doses of Vitamin C are recommended during any course of dental work.
- A prospective study reported in 2008, based on Vitamin C intake from fruit and vegetables, links a decreased risk of Type 2 diabetes with an increased plasma Vitamin C level. Other studies show several specific metabolic actions indicating Vitamin C’s regulatory effect on blood glucose. Vitamin C has also been used to stop damage to blood vessels caused by Type 1 diabetes (mellitus).
- A common type of male infertility where the sperm have a tendency to clump together has been shown to quickly improve with Vitamin C therapy. One study claimed fertility outcomes were 100% positive after two weeks.
- Low Vitamin C is implicated in cataract formation, as decreased levels in the lens of the eye correlate with increased severity of cataracts. Although some studies show increasing Vitamin C intake decreases cataract risk, others are inconclusive. Further work is needed to determine a protective effect and clarify the relationship.
Vitamin C supplement manufacturers vary in the recommended dosages stated on their labels, ranging from 1 to 3 gm (1000 to 3000 mg) daily for adults as a maintenance dose.