Vitamin C and chronic illnesses

At the Public Archives in Ottawa there is a painting by H.R. Perrigard in which a group of explorers, led by Jacques Cartier, and a number of natives are shown peering with great interest at a fallen tree. This might be dismissed as some strange peace ritual by those with neither an historical nor nutritional bent, but in actuality the natives are busy teaching Cartier and his group how to cure scurvy with a concoction made from the branches of a juniper tree. The natives beat the palefaces to the punch by about two hundred years, since it wasn't until 1747 that an English surgeon, James Lind, discovered that citrus fruit would cure the strange ailment befalling English seamen.

The treatment with oranges, lemons, and limes not only eliminated the symptoms of swollen limbs, hemorrhaging gums and skin, weakness and loss of teeth (not to mention the likelihood of death) but gave them the nicknames of "limeys" as well. The curative agent in the citrus fruit, of course, was ascorbic acid or vitamin C. While scurvy is one of the oldest known deficiency diseases (beri-beri ranks up there as well), vitamin C today is still a controversial vitamin...especially with the H1N1 virus raising its ugly head.

Scurvy has been around for such a long time that there was even a Latin word for it--"scorbutus"; hence ascorbic means "without scurvy". Vitamin C was synthesized in the laboratory in 1933, and it's been upward and onward ever since. Before getting into the controversial stuff let's see what ascorbic acid does for us in normal, recommended amounts.

Unlike the other water-soluble vitamins ascorbic acid is not known to act as a coenzyme in any of the metabolic processes. Its main function is involved with the production of collagen, which is part of all our connective tissue. The formation of collagen is important for wound healing and therapeutic doses of vitamin C are given to burn victims recovering from surgery. Collagen also features prominently in anti-aging ads from the cosmetic industry, but that's another story. When amino acids are being converted for neurotransmitter synthesis, vitamin C is there; it's also an important presence for the enhancement of iron absorption--an all round good fellow to have around. As little as 10 milligrams of ascorbic acid a day will keep you from getting scurvy, but for maximum health, more is recommended. How much more is wherein lies the rub. The usual dietary standard is 45-60 mg for an adult; Linus Pauling opted for 10,000 mg.

Which brings us to the fascinating subjects of vitamin C and the common cold and influenza, vitamin C and cancer, and vitamin C and heart disease.
Linus Pauling won two more Nobel Prizes than I ever will, and was certainly no dummy. His Nobels were, however, in chemistry and peace; not nutrition. The controversy boils down to a disagreement between Pauling's followers and other great scientists who have been unable to duplicate his findings. Pauling claimed that large doses of vitamin C will prevent and/or cure the common cold (some now claim the same benefit for the H1N1 flu), while opponents of the theory point out that since the body excretes excesses of the vitamin, these large doses are worthless.

The placebo effect in all this cannot be discounted. If one is ingesting a substance that one truly believes to be effective in preventing or curing a cold, then one might very likely experience just such an effect. The definitive study may have come from the Canadian army which found among its volunteers that while vitamin C didn't prevent colds, it did provide a less severe and shorter illness. More recently it's been found that those who routinely take a modest supplement of vitamin C are less likely to contract the cold virus.

There have been conflicting reports on the effectiveness of large doses of ascorbic acid in lowering serum cholesterol levels as well as its use in treating cancer patients. Regarding the latter, an interesting study was reported in the New England Journal of Medicine a few years back. This was a double blind study (neither the patient nor the doctor knows if the experimental substance or a placebo/sugar pill is being administered) in which one group of patients was given 10 grams (that's 10,000 mg) of ascorbic acid, while another group of similarly afflicted patients was given the placebo. No difference was found in survival time or severity of symptoms.

While citrus fruits are the excellent sources of vitamin C that come to mind, we mustn't forget strawberries, broccoli, tomatoes, cantaloupe, cabbage, potatoes and cranberries. Because it is quite unstable in light and air we should take certain precautions with vitamin C. For example, don't shred the cabbage too soon before the meal, don't let an uncovered container of orange juice hang around on the kitchen table. Frozen orange juice retains most of its original ascorbic acid, but once it's been reconstituted keep it covered and in the refrigerator.

The controversy over vitamin C will likely outlive me, but if you're "into" the stuff remember that large doses have been shown to be harmful to the kidneys and developing fetuses, not to mention the potential for fowling up diabetic tests. In my view the maximum daily intake for an adult shouldn't exceed 500 mg.