As textbooks of human genetics, paediatrics, and internal medicine all tell us, the fact that humans require vitamin C isn’t just a matter of nutrition: it reflects a basic genetic defect that all humans share – a biochemical inability to internally manufacture vitamin C.
Vitamin C is synthesized internally by almost all other species of animals, except chimpanzees, monkeys and other primate species, guinea pigs, an obscure bat found only in India, and humans. Cats, dogs, elephants, birds, horses, cows… all other species need no vitamin C from their diets at all! They synthesize vitamin C internally from glucose (blood sugar) using a series of four enzymes. When stressed in any way, all other animals immediately start to self-manufacture increased quantities of vitamin C to combat that stress.
Human liver cells contain the first three enzymes in the vitamin C synthesizing series, but the fourth enzyme is totally missing. When humans are stressed, the activity of those first three enzymes greatly increases, but no vitamin C is produced since that fourth enzyme is absent in humans. Unlike animals, we are genetically prevented from producing one of the most important anti-stress and detoxifying molecules present in all of nature, vitamin C. The human need for vitamin C is an inborn error of metabolism, a fortunately survivable genetic disease, and not just a nutritional problem.
Get healthy and STAY that way with vitamin C
When animals ingest carcinogens, their bodies immediately start to synthesize 10, 20, even 50 times as much vitamin C to help detoxify and get rid of the carcinogen. Human bodies try to make more vitamin C, but they can’t. When animals are injured, their bodies synthesize extra vitamin C to aid in tissue repair. (Vitamin C is key to the synthesis of collagen in connective tissue.) Again, human bodies try, but can’t. When animals are given drugs of any kind (including alcohol, nicotine and caffeine) their bodies synthesize significantly more vitamin C until the drugs are detoxified. Human bodies try to do the same, but can’t.
In fact, when animals start to become ill in any way, their bodies begin to synthesize much more vitamin C in an effort to head off the illness, and to shorten it – or at least reduce the symptoms over time – if it occurs.
One human study (which in a very practical way summarizes all of this and more) demonstrated that daily supplementation of vitamin C was able to extend life by six years for the men involved, and one year for the women. Since this study was started when the participants were in middle age or older, it’s likely that results would be even better if vitamin C supplementation was started at birth!
A few scientists who’ve seriously studied this question point out that compared to animals which synthesize their own vitamin C, if healthy adult humans made their own they would produce from 2 to 4g of vitamin C daily. Other scientists have observed that adult gorillas (another non-vitamin C synthesizing species) living in an area identical to the original human environment eat approximately 3 to 4g of vitamin C a day (calculated on a human-weight basis).
Take the ‘test’ to determine how much C you need
These comparisons give us general guidelines about appropriate supplemental quantities, but since we’re all individuals, I recommend an individualised approach (originated by Linus Pauling), which uses feedback from our own bodies. Known as the bowel-tolerance approach, it’s quite simple. Slowly increase the amount of supplemental vitamin C each day until you start getting excess gas or loose bowels. At that point your body is likely not able to use that quantity, so go back to the largest amount tolerable without producing loose bowels or excess gas. Most adults I work with find the tolerance point to be somewhere between 3 to 6g daily. However, when illness occurs, the tolerance point frequently increases to 20 to 30g or more daily, showing that our bodies need the extra help when we’re ill. Occasionally, people who’ve had severe viral illness have told me they’ve taken up to 100g daily for a day or two without any bowel problems at all.
Since vitamin C is water-soluble and rapidly used by our bodies, it’s logical to spread it out into at least two or even three intervals daily when we’re healthy, and as often as hourly when we’re ill. Remember, vitamin C isn’t a typical vitamin. You and I need it for the best of health because of a proven genetic problem.
There’s just one definite precaution: if you’ve formed calcium oxalate kidney stones, or come from a family who has had them, you should limit supplemental vitamin C to 1g daily unless you’re working with a healthcare professional knowledgeable in nutritional therapy. There’s a remote possibility that more vitamin C will increase the production of oxalate in those individuals. Fortunately, it’s easy to test for this possibility, and the risk is very small.
Wishing you the best of health,
Dr. Jonathan V. Wright
Nutrition & Healing
Vol. 9, Issue 1 • January 2015
Full references and citations for this article are available in the downloadable PDF version of the monthly Nutrition and Healing issue in which this article appears.