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by Dr. Phil Brown
Primer on Vitamin C
Vitamin C (ascorbic acid) is a very powerful nutrient and the premier water-soluble antioxidant. It participates in over 300 biochemical reactions in the body and is important in maintaining homeostasis as well as building tissue. Without adequate intake of vitamin C, humans develop scurvy, a complicated syndrome of biochemical changes leading to gradual breakdown of the body’s connective tissue and support structures.
Death is inevitable if vitamin C is not provided. It is truly essential to human life.
The U.S. National Academy of Sciences’ Institute of Medicine (NASIM) states that people get all the vitamin C they need from fruits and vegetables. Despite this, Americans consumed over 1 billion milligrams of vitamin C last year and spent almost $800 million in vitamin C?supplements.
New research into the actions of vitamin C has sparked a greater understanding of the remarkable health-promoting properties of this essential nutrient. The new evidence validates that vitamin C supports cardiovascular and respiratory function, cognition, bone development and mineralization, vision, and may even lower the risk of stress-related diseases and certain types of cancer.
Ever since Nobel Prize-winning scientist Linus Pauling first used vitamin C as a weapon against the common cold, vitamin C has been one of the “good guy” nutrients. However, most people don’t understand what it does, how it works and how many different ways it can enhance health and vitality.
A brief look at the many benefits of vitamin C include:
• Cardiovascular Health. New studies continue to link vitamin C to cardiovascular health. Heart disease is the leading cause of death for men and women aged 45 and older. High dietary vitamin C intake has been shown to significantly reduce the risk of death from heart attacks and strokes in numerous population studies. Also, researchers have found that vitamin C offsets spasms of the coronary arteries.
By scavenging free radicals, vitamin C may protect low-density lipoproteins (LDLs) and DNA from oxidative damage, and subsequently prevent atherogenesis. Vitamin C may also prevent atherogenesis through its role in the synthesis of collagen and prostacyclin, important components of vessel walls.
Dozens of clinical studies have shown that vitamin C levels correlate to total cholesterol and HDL cholesterol. However, in well-nourished individuals with normal blood levels of vitamin C who take supplemental vitamin C, there may be a threshold for the beneficial effects of vitamin C supplementation on total cholesterol and HDL cholesterol.
• Vision Health. According to the National Center for Health Statistics, about 10–30 percent of adults aged 70 and older have some form of vision impairment. And evidence is mounting that nutrition can influence the progression of diseases that impair vision such as glaucoma, cataracts and macular degeneration.
A recent Age-Related Eye Disease Study conducted by the National Eye Institute examined the impact of vitamin supplements on macular degeneration and cataracts. The study showed that vitamin C, combined with beta carotene, vitamin E and zinc, significantly retarded age-related macular degeneration.
Much research has been undertaken to establish the relationship between vitamin C intake and the development of cataracts. A significant risk reduction has been shown for people taking vitamin C.
• Immunity Booster. The ability of vitamin C to prevent and treat the common cold has been controversial for years, although most data suggests that vitamin C may shorten the duration and lessen the severity of symptoms. A recent study reported an 85 percent lower incidence in cold and flu symptoms with high vitamin C doses.
There is considerable evidence that vitamin C plays a vital role in maintaining the immune system. It enhances the killing response of infection-fighting white blood cells, promotes the production of interferon (an immune-stimulating substance secreted by lymphocytes), increases antibody responses and levels and stimulates secretion of thymic hormones. The high concentration of vitamin C in white blood cells, particularly lymphocytes, is rapidly depleted during infection and a relative vitamin C deficiency could ensue if vitamin C is not regularly replenished.
• Collagen Maintenance. Vitamin C is important for the formation and maintenance of collagen, the intercellular cement that binds tissues together. Collagen provides tensile strength to bones, cartilage, teeth, tendons and?ligaments. Since bone has an organic matrix containing collagen, vitamin C is necessary for bone formation as well.
There is a positive association between vitamin C and bone mineral density (BMD) in postmenopausal women which is enhanced in those with dietary calcium intakes of at least 500 mg. Long-term use of vitamin C supplements was associated with higher BMD in the early postmenopausal years among those who had never used estrogen.
Vitamin C also facilitates in skin collagen production, enhancing vitamin E activity, acting as an antioxidant to prevent harmful free radicals from damaging skin cells and reducing the amount of photo damage to skin cells caused by UVA and UVB rays. The net effect is reduction of fine lines, wrinkles and photo damage. Some forms of topical vitamin C have even been shown to reduce rosacea redness.
• Cancer. A recent controversy erupted when the Blair Lab at the University of Pennsylvania showed that in a test tube, vitamin C can boost the production of certain types of free radicals, which in turn damage DNA. According to Ian Blair, the lead researcher, this finding did not mean “vitamin C causes cancer.” In the body there are complex biochemical mechanisms involving multiple antioxidants that are not present in test tubes. Thus to conclude on the basis of such “out-of-body” methods that vitamin C causes cancer is irresponsible.
Vitamin C functions as an antioxidant to protect cellular structures, including genetic mechanisms, an enhancer of the immune system, and to protect against cancer-causing environmental irritants and pollutants. There are several studies that give evidence to the protective effects of vitamin C against cancer.
Lung, breast, cervical, pancreatic, colon and stomach cancer all have supportive studies that show reduction of risk or lower death rates with vitamin C intake. In some cases, such as lung cancer, investigations into the role of vitamin C against the illness suggest that there may be a protective effect of vitamin C intake.
Vitamin C and Free Radicals
Besides the many benefits of vitamin C in the prevention and treatment for the physical ailments listed above, it is also the antioxidant against the damage of free radicals. Free radicals are unstable and highly reactive molecules, the majority of which are formed during normal cellular metabolism.
Excessive numbers of free radicals reduce metabolic efficiencies, mutate cells, damage genes, weaken organ systems, increase the risk of cancer, accelerate aging and even wrinkle skin. In other words, free radicals are the reason why we age. Free radicals enter the body in cigarette smoke, environmental pollutants, volatile chemicals and fried foods. They also are produced within the skin from sunlight.
Antioxidants neutralize free radicals and vitamin C is the antioxidant to do so. It acts by donating an electron to stabilize a free radical. Although the body naturally produces antioxidants, fewer are produced with aging. The antioxidant properties of vitamin C become more important as aging occurs, especially if there is stress or disease.
Many of the benefits of vitamin C supplementation stem from its antioxidant properties. For example, vitamin C can reduce the extra free radicals resulting from the increased oxygen intake and sugar burned during exercise. Vitamin C represents a safe and effective way to improve pulmonary function in people whose breathing passages are compromised by inflammation (e.g. asthmatics, irritants such as cigarette smoke, smog or volatile gases).
Vitamin C Levels and Forms
Vitamin C intake can be achieved through a diet rich in fruits and vegetables—which is always recommended. However, even careful dietary selection will typically yield vitamin C levels around 200 mg per day and such dietary regimens are not widely practiced by most Americans. Vitamin supplementation is a?practical option to help people make up the difference between their nutritional needs and their food intake.
How much vitamin C is recommended? According to the Food and Nutrition Board, U.S. National Academy of Science, the Recommended Daily Allowance (RDA) for vitamin C for the U.S. and Canada was set at 90 mg for men and 75 mg for women. However, several studies have shown that tissue saturation is achieved only at much higher levels.
Extensive evidence indicates that consumption of vitamin C is safe, even at levels many times higher than the RDA. No adverse effects have been observed in controlled trials of vitamin C supplementation, even when large doses have been administered for several years.
The 500-milligram tablet was historically one of the top selling dosages of vitamin C, but recently people are shifting to the 1,000-milligram tablet. This suggests that more people are becoming aware of the importance of vitamin C and the fact that it won’t accumulate in the body.
The average person does not know how much vitamin C his or her body needs. Stress, smoke, pollution and other factors may cause the body to use excessive amounts of vitamin C—making higher levels of supplementation beneficial. Vitamin C is a water-soluble vitamin. One of the advantages of this is that the body will readily and easily excrete the excess vitamin C that is not utilized.
One concern of vitamin C being water-soluble is that even though many foods and beverages are fortified with it, the amount on the label is not truly indicative of the intake levels. Vitamin C is a nutrient capable of powerful effects but chemically it’s a bit of a wimp. It is readily destroyed by high temperatures, strong light and water. In fact, if orange juice is stored at room temperature for one month, about 20 percent of the original vitamin C is lost.
Another concern with ordinary vitamin C is that high levels can cause gastric upsets and diarrhea. If taken in a chewable form, vitamin C can also erode tooth enamel. These effects are due to acidity of ordinary vitamin C and may be reduced or eliminated with non-acidic mineral ascorbates.
A neutral, stable form of vitamin C exists and is called Ester-C® Calcium Ascorbate. Ester-C is a non-acidic complex of calcium ascorbate and vitamin C metabolites. It will not upset the stomach or erode tooth enamel, even when taken at high levels. Preliminary studies have shown that the metabolites may enhance the cellular absorption of vitamin C. The Ester-C brand is manufactured by Inter-Cal Nutraceuticals of Prescott, Arizona.
Summary
Evidence is accumulating that vitamin C functions beyond its role in the prevention of deficiency diseases such as scurvy. It may reduce the risk of cancer, protect the heart, keep vision sharp, reduce body wear and tear and fend off environmental insults. Vitamin C may slow the aging process, help cognitive abilities and keep skin supple and youthful.
There is no doubt that the body requires dietary vitamin C every day of the year. Regular consumption of fruits and vegetables may supply the needed amounts to prevent scurvy but for optimum cellular function, tissue health and thus vitality, supplements containing vitamin C provide the means to achieve consistent levels.
Today clinicians and scientists better understand the different roles that vitamin C plays in biological systems. As more consumers come to appreciate the diverse and important roles this essential nutrient plays in enhancing their health, perhaps the incidence of degenerative disease will lessen. Perhaps people will feel?better. Perhaps people will live longer.
Dr. Phil Brown is the Ester-C Product Manager for Inter-Cal Nutraceuticals. Prior to joining the company he was a small animal?veterinarian in Cape Cod, MA and developed and marketed natural foods, supplements and treats for dogs, cats and horses.
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