Functions of Vitamin C (Ascorbic acid/Ascorbate)
Major WATER-Soluble Antioxidant
In the body - Antioxidants sacrifice themselves on our behalf. Antioxidants donate their electrons to free radicals which would otherwise steal them from and so damage parts of your body. Likewise in food, antioxidants protect it from decay.
- AA is a Free Radical Scavenger - oxidizing free radicals and harmful oxygen-derived species. E.g. hydroxyl radical, hydrogen peroxide and singlet oxygen; AA being a water-soluble antioxidant is significant because ~70% of the body is water. The brain is an easy target for oxidative damage and since antioxidant levels tend to diminish with age, it is not unexpected to find more brain related problems in the elderly, such as Alzheimer's and Parkinson's.
In Foods - AA, predominant in fresh foods, is easily oxidized to DHAA (which also has antiascorbutic activity) during processing, storage, preparation and cooking.
DHAA is then either converted back to AA (by an enzymatic process involving dehydro-ascorbate reductase), or oxidized into irreversible, non-ascorbutic products.
- AA is a strong antioxidant in an AQUEOUS solution
-AA is much more easily oxidized in an ALKALINE and AEROBIC environment
- UV RADIATION (e.g. sunlight) will oxidize AA, regardless of oxygen presence.
FManufacture of collagen
Collagen is the main protein substance which holds most of the body tissue together - giving structure to bones, cartilage, tendons, ligaments, muscle, blood vessels, heart valves, invertebral discs, cornea, retina, skin, teeth, capillary walls, joint linings and the ground substance between cells. AA works as a coenzyme to convert (hydroxylate) amino acids proline and lysine to hydroxyproline (needed for a stable extracellular matrix) and hydroxylysine (needed for formation of cross-links in the fibers), both important to the collagen structure.
- Aging lines and wrinkles in the skin - are the result of decreased collagen production.
- Examples of Collagen necessity - wound repair, healing burns, healthy gums, arterial integrity, prevention of easy bruising, and bone fracture.
Major Anti-inflammatory / Antiviral / Antibacterial / Antifungal activities
. . . as a result of Vitamin C's multiple roles in immune system enhancement, antioxidant ability, adrenal support and collagen production
Anti-inflammatory Activity - In its antioxidant and immunity roles, vitamin C combats inflammation-causing microorganisms, irritants, and free radicals, improving conditions such as cystitis, bronchitis, prostatitis, bursitis, osteo/rheumatoid arthritis, and chronic skin problems, e.g. dermatitis; vitamin C's enhancementof collagen production may also improve joint membrane integrity in arthritis;In gouty arthritis, vitamin C improves the elimination of the irritant, uric acid, through the kidneys.
Anti-Bacterial Activity - “It is likely that the bactericidal effect of ascorbic acid takes place by way of free radicals formed during oxidation of ascorbic acid in the presence of hydrogen peroxide. Hydrogen peroxide is formed during the reaction of ascorbic acid and oxygen, and macrophages lack peroxidase. It has been shown that ascorbic acid and hydrogen peroxide together have a pronounced bactericidal effect, which is increased by a small concentration of copper ions. The presence of free radicals has been demonstrated by electron-spin resonance spectroscopy, and the bactericidal activity is completely inhibited by free-radical inhibitors.”
1974 (Nov)Linus Pauling, Nat. Acad. Science
- Several bacterial viruses (aka bacteriophage, infects/replicates inside bacteria) are 99% inactivated by 20 min. exposure to ascorbate concentrations - that can be reached in the blood by a large C intake
Murata, A., K. Kitagawa, and R. Saruno. 1971. Inactivation of bacteriophages by ascorbic acid. Agr. Biol. Chem. 36:1065-1067.
- Viral inactivation does not occur in the absence of oxygen - study concluded that deactivation results from single-strand scissions of phage DNA by free radicalsformed during the autoxidation of AA
Murata, A., and K. Kitagawa. 1973. Mechanism of inactivation of bacteriophage J1 by ascorbic acid. Agr. Biol. Chem. 37:1145-1151.
- Some protection against viral diseases: poliomyelitis, hepatitis, fever blisters, shingles, virus pneumonia, measles, chicken pox, virus encephalitis, mumps, infectious mononucleosis (Stone I (1972) “The Healing Factor: Vitamin C against diseaseâ€)
Controls allergic response
In the presence of copper ions, vitamin C prevents histamine accumulation - and assists in its degradation/elimination. Evidence exists that vitamin C also modulates prostaglandin synthesis to modulate histamine response and cause relaxation
Seems to enhance combative white blood cell (WBC) function and activity; C helpful against bacterial, viral, and fungal diseases
✔ Increases interferon levels
✔ Increases secretion of thymic hormones, which stimulate WBC production
✔ Inhibits oxidative destruction of WBC's - increases their mobility
✔ Increases serum immunoglobulins (antibodies)
✔ Leukocytes have highest C concentration of any blood cells
✔ Some studies show WBC increase at doses of 3-10g of vitamin C
Needed for body's enzyme systems
300 known enzyme systems require vitamin C
Heavy metal chelation
Vitamin C is a powerful chelating agent for heavy metals
Helps Increase Thyroid Hormone Production
Vitamin C stimulates production of thyroxine (T4)
Reduce blood cholesterol levels
Aids in cholesterol metabolism and elimination
Aids hepatic production of bile from cholesterol
Works synergistically with Vitamin E and Beta-carotene - Vitamin C, vitamin E, and beta-carotene both reinforce and extend each other's antioxidant properties and activities.
Indirectly protects vitamins A, E, and some B vitamins from oxidation (including riboflavin, thiamine, folic acid, and pantothenic acid);
Enhances B-vitamins - By vitamin C's influence on intestinal flora. Helps metabolize folic acid (Vitamin B9) by helping to regulate conversion of folic acid to folinic acid;