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.