What is the role of vitamin C in my body?

Dr. Michael Roizen, MD
Internal Medicine
Vitamin C helps keep the arteries clear by inhibiting fat oxidation in the walls of your blood vessels. It converts cholesterol to a form (bioacids) that can be washed out of the body easily, not adding to the problem of lipid buildup. Because vitamin C is water-soluble, it enters the cells that make up the wall of the vessels themselves, binding to free radicals (unstable forms of oxygen) lurking inside the cell, precisely in the place where those free radicals are likely to cause DNA damage. Because of its healing capabilities, vitamin C helps maintain a healthy matrix (intracellular substance) in the blood vessels, repairing the vessel walls when they become damaged.
Although severe vitamin C deficiency, which causes scurvy, is rare, 40 percent of Americans are moderately deficient in this powerful antioxidant. Vitamin C enhances iron absorption, supports collagen formation, and strengthens immune function.
Heart Health
USDA researchers have linked low vitamin C with elevated C-reactive protein, an inflammatory marker for heart disease. Vitamin C also combats the oxidation of LDL (bad) cholesterol, preventing deposits and facilitating blood flow.

Bone and Joint Health
Research shows vitamin C may support bone health by promoting collagen formation. According to a Boston University study, people who got less than 150 milligrams daily of vitamin C had faster cartilage breakdown. Studies have linked higher levels of vitamin C with greater forearm bone-mineral content in postmenopausal women.

Lung Health
Vitamin C could help alleviate symptoms of respiratory ailments like cystic fibrosis and asthma by loosening viscous secretions in the air passage, which lowers the risk of infection and makes breathing easier. Because smokers and people exposed to secondhand smoke tend to have deficient vitamin C levels in the blood, the Food and Nutrition Board recommends that they consume an additional 35 milligrams of vitamin C per day. Some studies have suggested that even higher amounts may be required to achieve the same levels as in nonsmokers.

Stomach Health
In a 2004 trial, a team of Finnish and American researchers found that fruit and vitamin C consumption was associated with an approximately 45 percent reduction of risk in noncardia cancer, the most common form of stomach cancer in most parts of the world.

Skin Health
New British research looked into the dietary habits of more than 4,000 American women and found that those who got the most vitamin C from their diets had smoother, moister and more youthful-looking skin. Not only did the study find more signs of aging -- wrinkles, dryness, thinning skin -- among those with lower vitamin C intakes, it concluded that a high-fat diet also tended to make women look old for their age.

Fight fat with Vitamin C
Raising vitamin C intake boosts your body’s ability to burn fat. Scientists point to vitamin C’s role in the manufacture of the amino acid carnitine, which helps flush fatty acids from the body.
Michael T. Murray, ND
Naturopathic Medicine
Vitamin C is perhaps the most publicized vitamin. The primary function of vitamin C is the manufacture of collagen. Vitamin C is involved in the joining of the amino acids lysine and proline to form hydroxylysine and hydroxyproline. The result is a very stable collagen structure. Since collagen is an important protein in the structures that hold our body together, including cartilage, connective tissue, ligaments, and tendons, vitamin C is vital for wound repair, healthy gums, and the prevention of easy bruising.

In addition to its role in collagen manufacture, vitamin C is also critical to immune function, the manufacture of certain nerve transmitting substances and hormones, and the absorption and utilization of other nutritional factors. Vitamin C is also a very important nutritional antioxidant.

Numerous experimental, clinical, and population studies have shown increased vitamin C intake to result in a number of beneficial effects, including reducing cancer rates; boosting immunity; protecting against pollution and cigarette smoke; enhancing wound repair; increasing life expectancy; and reducing the risk of developing cataracts. Many claims have also been made about the role of vitamin C in enhancing the immune system, especially regarding the prevention and treatment of the common cold. However, despite numerous positive clinical and experimental studies, for some reason this effect is still hotly debated. From the biochemical viewpoint, there is considerable evidence that vitamin C plays a vital role in many immune mechanisms.

Vitamin C has been shown to increase many different immune functions, including enhancing white blood cell function and activity; and increasing interferon levels, antibody responses, antibody levels, secretion of thymic hormones, and the integrity of ground substance, the basic material that causes cells to adhere together. Vitamin C also possesses many biochemical effects very similar to those of interferon, the body's natural antiviral and anticancer compound. The high concentration of vitamin C in white blood cells, particularly lymphocytes, is rapidly depleted during infection, and a relative vitamin C deficiency may ensue if vitamin C is not regularly replenished.
Encyclopedia of Healing Foods

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Encyclopedia of Healing Foods

From the bestselling authors of The Encyclopedia of Natural Medicine, the most comprehensive and practical guide available to the nutritional benefits and medicinal properties of virtually everything...

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.