Even though for most New Zealanders the flu season is over and summer is on its way, it’s very important to understand that we all need optimal vitamin C every day of the year.
Did you know that the only mammals on the planet that don’t make vitamin C in their bodies are humans, primates, guinea pigs and fruit bats?
In the body of a vitamin C-making mammal, the vitamin C molecule is made from a few small modifications to the glucose molecule. While glucose is in abundant supply in humans and animals, four enzymes are required to convert glucose into vitamin C. Humans have only three of these enzymes, having lost the ability to make the fourth L-gulonolactone oxidase somewhere throughout evolution.
Of the four mammals mentioned above, the human is the only one that eats meat and is unable to produce vitamin C. Primates, guinea pigs and fruit bats seem to know instinctively that to stay healthy they must ingest large quantities of foods containing vitamin C. Fruit bats are so named because they favour fruit as a primary source of food.
In mammals that retained the ability to make vitamin C, it is made in response to all sorts of stress, especially the stress of infection. Under stress, that amount can be very significantly increased. A goat, for instance, can make up to 200 mgs/kg on a daily basis but will make up to 100,000 mgs of vitamin C daily if under stress.
Why is it then that the RDA (recommended daily allowance) for humans is 1 mg/kg – approximately 60 to 90mgs per day? If vitamin C is so important to animals why do humans require so little? This is a very important question. Anyone who takes even the slightest interest in vitamin C would soon realise that humans have been significantly short-changed.
RDA, in my opinion, should stand for Ridiculous Daily Allowance and it’s almost certainly the reason why diseases so prevalent in humans are almost non-existent in animals that make large amounts of vitamin C.
It is very interesting to note that mammals that make their own vitamin C can live 8-10 times beyond their age of physical maturity. Mammals without this ability have difficulty reaching 3-4 times.
It is even more interesting to contemplate the impact on mankind if it were possible to reinstall the L-Gulonolactone Oxidase enzyme in humans. In a study conducted by Sato et al. in 1966, researchers administered this enzyme (harvested from chickens or rats) to guinea pigs on a vitamin C-deficient diet. The guinea pigs survived and Dr Thomas Levy in his fascinating and thought-provoking book Vitamin C – Curing the Incurable suggests that this research “should stimulate further research into the feasibility of giving such direct enzyme replacement therapy to humans”.
It is incredibly rare, according to Dr Levy, for an inborn error in metabolism to be shared by all humans. Considering anecdotal evidence of a certain individual living to 100 while smoking and drinking daily, Dr Levy agrees that one can be blessed with a very efficient immune system, but he suggests that the ability to synthesise L-Gulonolactone Oxidase, at least to a limited degree, could also be the reason for an otherwise long and healthy life.
To support this, a UCLA study in 1992 involving 11,348 participants over 10 years showed that men with the highest blood levels of vitamin C lived for up to six years longer than those with the lowest levels.
Albert Szent Gyorgyi, who is credited with discovering vitamin C, said: “If you don’t take ascorbic acid with your food you get scurvy, so the medical profession said that if you don’t get scurvy you must be all right. I think this is a very grave error.”