Vitamin C (Ascorbic Acid) is a very important essential nutrient—that is, we must obtain it from diet. It is found only in the fruit and vegetable foods and is highest in fresh, uncooked foods. Vitamin C is one of the least stable vitamins, and cooking can destroy much of this water-soluble vitamin from foods.
In recent years, the C of this much-publicized vitamin has also stood for controversy. With Linus Pauling and others claiming that vitamin C has the potential to prevent and treat the common cold, flus, and cancer, all of which plague our society, concern has arisen in the medical establishment about these claims and the megadose requirements needed to achieve the hoped-for results. Some studies suggest that these claims have some validity; however, there is more personal testimony from avid users of ascorbic acid than there is irrefutable evidence. There has also been some recent research that disproves the claims about treatment and prevention of colds and cancer with vitamin C. However, in most cases, studies showing vitamin C to be ineffective used lower dosages than Dr. Pauling recommended. Overall, vitamin C research is heavily weighted to the positive side for its use in the treatment of many conditions, including the common cold.
C also stands for citrus, where this vitamin is found. It could also stand for collagen, the protein "cement" that is formed with ascorbic acid as a required cofactor. Many foods contain vitamin C, and many important functions are mediated by it as well.
Vitamin C is a weak acid and is stable in weak acids. Alkalis, such as baking soda, however, destroy ascorbic acid. It is also easily oxidized in air and sensitive to heat and light. Since it is contained in the watery part of fruits and vegetables, it is easily lost during cooking in water. Loss is minimized when vegetables such as broccoli or Brussels sprouts are cooked over water in a double boiler instead of directly in water. The mineral copper, in the water or in the cookware, diminishes vitamin C content of foods.
Ascorbic acid was not isolated from lemons until 1932, though the scourge of scurvy, the vitamin C deficiency disease, has been present for thousands of years. It was first written about circa 1500 B.C. and then described by Aristotle in 450 B.C. as a syndrome characterized by lack of energy, gum inflammation, tooth decay, and bleeding problems. In the 1700s, high percentages of sailors with the British navy and other fleets died from scurvy, until James Lind discovered that the juice of lemons could cure and also prevent this devastating and deadly disease. The ships then carried British West Indies limes for the sailors to consume daily to maintain health, and thus these sailors became known as "limeys." Other cultures of the world discovered their own sources of vitamin C. Powdered rose hips, acerola cherries, or spruce needles were consumed regularly, usually as teas, to prevent the scurvy disease.
In earlier times, humans consumed large amounts of vitamin C in their fresh and wholesome native diet, as apes (another species that does not make vitamin C) still do. Most other animals, except guinea pigs, produce ascorbic acid in the liver from glucose, and in relative amounts much higher than we get from our diets today. For this reason, Dr. Pauling and others feel that our bodies need somewhere between 2,000 and 9,000 mg. of vitamin C daily. These amounts seem a little high to me, given the basic food values of vitamin C. Some authorities feel we need 600–1,200 mg. daily based on extrapolations from the historical herbivore, early-human diet. These levels can be obtained today by eating sufficient fresh food; a diet that includes foods with high levels of vitamin C can provide several grams or more per day.
Ascorbic acid is readily absorbed from the intestines, ideally about 80–90 percent of that ingested. It is used by the body in about two hours and then usually out of the blood within three to four hours. For this reason, it is suggested that vitamin C supplements be taken at four-hour intervals rather than once a day; or it may be taken as time-released ascorbic acid. Vitamin C is used up even more rapidly under stressful conditions, with alcohol use, and with smoking. Vitamin C blood levels of smokers are much lower than those of nonsmokers given the same intakes. Other situations and substances that reduce absorption or increase utilization include fever, viral illness, antibiotics, cortisone, aspirin and other pain medicines, environmental toxins such as DDT, petroleum products, or carbon monoxide, and exposure to heavy metals such as lead, mercury, or cadmium. Sulfa antibiotics increase elimination of vitamin C from the body by two to three times.
Some ascorbic acid is stored in the body, where it seems to concentrate in the organs of higher metabolic activity. These include the adrenal glands (about 30 mg.), pituitary, brain, eyes, ovaries, and testes. A total of about 30 mg. per pound of body weight. We likely need at least 200 mg. a day in our diet to maintain body stores—much more if we smoke, drink alcohol, are under stress, have allergies, are elderly, or have diabetes.
Vitamin C is a very complex and important vitamin. The recommended amounts vary more widely than those for any other nutrient, ranging from 100–80 or 100 grams daily, depending on the condition. C is also the most commonly supplemented vitamin among the general public, because of either the popular press or its good effect, or because of the other common C—the "cold."
Sources: The best-known sources of vitamin C are the citrus fruits—oranges, lemons, limes, tangerines, and grapefruits. The fruits with the highest natural concentrations are citrus fruits, rose hips, and acerola cherries, followed by papayas, cantaloupes, and strawberries. Good vegetable sources include red and green peppers (the best), broccoli, Brussels sprouts, tomatoes, asparagus, parsley, dark leafy greens, cabbage, and sauerkraut. There is not much available in the whole grains, seeds, and beans; however, when these are sprouted, their vitamin C content shoots up. Sprouts, then, are good foods for winter and early spring, when other fresh fruits and vegetables are not as available. Animal foods contain almost no vitamin C; though fish, if eaten raw, has enough to prevent deficiency symptoms.
Natural vitamin C supplements are usually made from rose hips, acerola cherries, peppers, or citrus fruits. Vitamin C can be synthesized from corn syrup, which is high in dextrose, much as it is made from glucose in most other animals’ bodies. Synthetic ascorbic acid, though it can be concentrated for higher doses than natural extracts, is still usually made from food sources. Sago palm is another fairly new source of vitamin C supplements. It is used primarily as a lower allergenic source than the corn-extracted ascorbic acid.
Functions: One important function of vitamin C is in the formation and maintenance of collagen, the basis of connective tissue, which is found in skin, ligaments, cartilage, vertebral discs, joint linings, capillary walls, and the bones and teeth. Collagen, and thus vitamin C, is needed to give support and shape to the body, to help wounds heal, and to maintain healthy blood vessels. Specifically, ascorbic acid works as a coenzyme to convert proline and lysine to hydroxyproline and hydroxylysine, both important to the collagen structure.
Vitamin C also aids the metabolism of tyrosine, folic acid, and tryptophan. Tryptophan is converted in the presence of ascorbic acid to 5-hydroxytryptophan, which forms serotonin, an important brain chemical. Vitamin C also helps folic acid convert to its active form, tetrahydrofolic acid, and tyrosine needs ascorbic acid to form the neurotransmitter substances dopamine and epinephrine. Vitamin C stimulates adrenal function and the release of norepinephrine and epinephrine (adrenaline), our stress hormones; however, prolonged stress depletes vitamin C in the adrenals and decreases the blood levels. Ascorbic acid also helps thyroid hormone production, and it aids in cholesterol metabolism, increasing its elimination and thereby assisting in lowering blood cholesterol.
Vitamin C is an antioxidant vitamin. By this function, it helps prevent oxidation of water-soluble molecules that could otherwise create free radicals, which may generate cellular injury and disease. Vitamin C also indirectly protects the fat-soluble vitamins A and E as well as some of the B vitamins, such as riboflavin, thiamine, folic acid, and pantothenic acid, from oxidation. Ascorbic acid acts as a detoxifier and may reduce the side effects of drugs such as cortisone, aspirin, and insulin; it may also reduce the toxicity of the heavy metals lead, mercury, and arsenic.
Vitamin C is being shown through continued research to stimulate the immune system; through this function, along with its antioxidant function, it may help in the prevention and treatment of infections and other diseases. Ascorbic acid may activate neutrophils, the most prevalent white blood cells that work on the frontline defense in more hand-to-hand combat than other white blood cells. It also seems to increase production of lymphocytes, the white cells important in antibody production and in coordinating the cellular immune functions. In this way also, C may be helpful against bacterial, viral, and fungal diseases. In higher amounts, ascorbic acid may actually increase interferon production and thus activate the immune response to viruses; it may also decrease the production of histamine, thereby reducing immediate allergy potential. Further research must be done for more definitive knowledge about vitamin C’s actions in the prevention and treatment of disease.
Uses: There are a great many clinical and nutritional uses for ascorbic acid in its variety of available supplements. C for the common cold is indeed used very widely; its use in the treatment of cancer is more controversial, probably because of the seriousness of the disease and the political environment within the medical system—anything nutritional or alternative in regard to cancer therapy is looked upon with skepticism by orthodox physicians. For the prevention of cancer, there is reason for more optimism about the usefulness of vitamin C (as well as the other antioxidant nutrients—vitamin E, selenium, beta-carotene, and zinc) because of its effect in preventing the formation of free radicals (caused mainly by the oxidation of fats), which play a role in the genesis of disease.
Given the functions of vitamin C alone, it has a wide range of clinical uses. For the prevention and treatment of the common cold and flu syndrome, vitamin C produces a positive immunological response to help fight bacteria and viruses. Its support of the adrenal function and role in the production of adrenal hormones epinephrine and norepinephrine can help the body handle infections and stress of all kinds. Because of this adrenal-augmenting response, as well as thyroid support provided by stimulating production of thyroxine (T4) hormone, vitamin C may help with problems of fatigue and slow metabolism. It also helps counteract the side effects of cortisone drug therapy and may counteract the decreased cellular immunity experienced during the course of treatment with these commonly used immune-suppressive drugs.
Because of ascorbic acid’s role in immunity, its antioxidant effect, the adrenal support it provides, and probably its ability to make tissues healthy through its formation and maintenance of collagen, vitamin C is used to treat a wide range of viral, bacterial, and fungal infections and inflammatory problems of all kinds. I have used vitamin C successfully in many viral conditions, including colds, flus, hepatitis, Herpes simplex infections, mononucleosis, measles, and shingles. Recently, vitamin C has been shown in some studies to enhance the production and activity of interferon, an antiviral substance produced by our bodies. To affect these conditions, the vitamin C dosage is usually fairly high, at least 5–10 grams per day, but it is possible that much smaller doses are as effective. Vitamin C is also used to treat problems due to general inflammation from microorganisms, irritants, and/or decreased resistance; these problems may include cystitis, bronchitis, prostatitis, bursitis, arthritis (both osteo- and rheumatoid), and some chronic skin problems (dermatitis). With arthritis, there is some suggestion that increased ascorbic acid may improve the integrity of membranes in joints. In gouty arthritis, vitamin C improves the elimination of uric acid (the irritant) through the kidneys. Ascorbic acid has also been helpful for relief of back pain and pain from inflamed vertebral discs, as well as the inflammatory pain that is sometimes associated with rigorous exercise. In asthma, vitamin C may relieve the bronchospasm caused by noxious stimuli or when this tight-chest feeling is experienced during exercise.