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; although further research must be done for more definitive knowledge about vitamin C’s actions in the prevention and treatment of disease.

Requirements:

The RDA for adults is considered to be 60 mg. We need only about 10–20 mg. to prevent scurvy, and there is more than that in one portion of most fruits or vegetables. Infants need 35 mg.; about 50 mg. between ages one and fourteen and 60 mg. afterward are the suggested minimums. During pregnancy, 80 mg. are required; 100 mg. are needed during lactation. Realistically, between 100–150 mg. daily is a minimum dosage for most people.

Vitamin C needs, however, are increased with all kinds of stress, both internal (emotional) and external (environmental). Smoking decreases vitamin C levels and increases minimum needs. Birth control pills, estrogen for menopause, cortisone use, and aspirin also increase ascorbic acid requirements. Both nicotine and estrogen seem to increase copper blood levels, and copper inactivates vitamin C. In general, though, absorption of vitamin C from the intestines is good. Vitamin C (as ascorbic acid) taken with iron helps the absorption of iron (and many minerals) and is important in treating anemia, but the iron decreases absorption of the ascorbic acid. Overall, it is probably best to take vitamin C as it is found in nature, along with the vitamin P constituents (discovered later)—the bioflavonoids, rutin, and hesperidin. These may have a synergistic influence on the functions of vitamin C, although there is no conclusive research on humans to support this theory.

Vitamin C is the most commonly consumed nutrient supplement and is available in tablets, both fast-acting and time-released, in chewable tablets, in powders and effervescents, and in liquid form. It is available as ascorbic acid, L-ascorbic acid, and various mineral ascorbate salts, such as sodium or calcium ascorbate.

Our suggestion for vitamin C use is about 2–4 grams per day with a typical active and healthy city lifestyle. Requirements for vitamin C vary and may be higher according to health, age (needs increase with years), weight, activity and energy levels, and general metabolism. Stress, illness, and injuries further increase the requirements for ascorbic acid.