What is Vitamin C's Role in Human Health

What is vitamin C? Everybody knows about vitamin C, but the world's most commonly used supplement has potential beyond what most users expect.

"Pure" Vitamin C Isn't the Best Vitamin C

Back in the 1930's, Hungarian chemist Albert Szent-Györgyi was hailed as the discoverer of vitamin C. A century after the British Navy discovered that limes and lemons could prevent the dread vitamin-deficiency disease scurvy, Szent-Györgyi discovered that the compound in limes, lemons, and many other plant foods that healed scurvy was vitamin C. Only that's not all of the story.

After the announcement of the discovery, the Hungarian Nobel laureate discovered that sometimes vitamin C powder cured scurvy, and sometimes it didn't. Vitamin C apparently needed some kind of co-factor to do its work. Szent-Györgyi experimented with various kinds of supplemental foods, and he finally discovered that scurvy patients who were given goulash got over their disease. The "something" in goulash that made them well, the scientist reasoned, had to be in the paprika, so he named the co-factor vitamin P.

In the English-speaking world we call this co-factor bioflavonoids. Whole food bioflavonoids are essential for vitamin C to do its job. We can get them from our diets, or we can get them with the vitamin C in supplements, but vitamin C never does all the work of healing on its own.

What Does Vitamin C Do for the Body?

Fresh Fruits

The body absorbs vitamin C along with salt and sugars released from the digestion of food. Vitamin C, for the most part, does not "seep" into the body. It has to be transported with sodium or certain kinds of sugar.

When we consume very little vitamin C, a very high percentage of the vitamin C in food is absorbed into the bloodstream. When consume a lot of vitamin C, a relatively low percentage of the vitamin C in food is absorbed into the bloodstream. If you only get 100 mg of vitamin C a day, about 98 mg will get into circulation. If you take 12,000 mg of vitamin C a day, about 2,000 mg will actually be absorbed. Higher amounts of vitamin C can be taken by injection, but your digestive tract can only handle about 2,000 mg a day.

Inside the body, the adrenal glands, retina, corpus luteum (progesterone-producing tissue in pregnant women and menstruating women during the second half of their menstrual cycle), pituitary, and thymus gland all concentrate vitamin C. This means that stress hormones, vision, women's reproductive cycles, most hormones, and immunity all respond to vitamin C.

Other organs that are especially dependent on vitamin C as an antioxidant include the brain, lungs, testicles in men, thyroid, and the lining of the intestine. A key but often overlooked function of vitamin C is to regulate the absorption of countless other digested substances from food.

Still More Functions of Vitamin C

Some other important but seldom publicized functions of vitamin C in human health include:

Of course, the best known application of vitamin C is fighting colds and flu. What vitamin C does realy isn't to kill the virus, but rather to stop the immune system from over-reacting to it. Taking vitamin C slows down the production of histamine that otherwise would literally explode inside cells lining the nose and throat, killing the cell to get rid of the virus by making mucus.

If you have a high metabolism, you probably don't need as much vitamin C. But if you are already run down before you catch a cold, stopping inflammation and mucus formation is probably exactly what you need in the first 24 to 48 hours of the infection. Vitamin C also helps fight allergies.

Why Do We Need Vitamin C Supplements?

Or do we need vitamin C supplements? For fighting cancer, it's really necessary to get vitamin C by intravenous (IV) infusion, or you just don't get enough. And for day to day function, it's not that hard to get enough vitamin C if you eat your recommended nine servings of fruit and vegetables every day. For the rest of us, at least a little supplemental vitamin C won't hurt. You just don't need very high doses. A maintenance dose of up to 500 mg a day, but no more, is best.

Are There People Who Should Not Take Vitamin C Supplements?

Some people should not take vitamin C supplements. If you have the iron overload disease called hereditary hemochromatosis, taking vitamin C will cause your gut to absorb too much iron from food. If are pregnant, then it's important to take vitamin C with bioflavonoids and vitamin K for the stability of the womb. And if you feel you need more than 2,000 mg of vitamin C a day for any reason, be aware that stomach upset is a real possibility. Otherwise, however, vitamin C is safe and remarkably cost effective insurance against vitamin deficiency.

Selected Reference:

Khaw, Kay-Tee; Bingham, Sheila ; Welch, Ailsa ; Luben, Robert; Wareham, Nicholas; Day, Nicholas (March 2001). "Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study. European Prospective Investigation into Cancer and Nutrition". Lancet 357 (9257): 657–63.