Once we get into the school year, we don't want to talk about "C"s so much (as As and Bs), so we'll cover Vitamin C as August's Of the Month topic!

Vitamin C is a real powerhouse of a vitamin with an interesting history and a great amount of controversy.  We'll touch on controversy, but let's start with the things we know for sure about this essential nutrient.

History.  Perhaps you've heard of scurvy...perhaps you even have some vague memory of a story about sailors and lemons having something to do with it.  Indeed, when civilizations began taking long sea journeys, they started having problems now known to be caused by a lack of Vitamin C.  Ancient Roman, Egyptian and Greek military seamen suffered.  Vasco De Gama (another vague memory...?) lost 2/3 of his crew in 1497 to scurvy.  From 1556-1857, 114 scurvy epidemics were reported.  In 1593, British Admiral Sir Richard Hawkins protected sailors from scurvy with oranges and lemons.  But it wasn't until 1747 when James Lind repeated a similar experiment  that the British fleet officially prescribed lemon juice for all sailors.  That advice went unheeded in the United States, however, until 1895, even though 30,000 soldiers died from scurvy in the Civil War.  In 1928 Albert Szent-Gyorgyi isolated a substance from ox adrenal glands that he later (1932) proved to be Vitamin C and he received a Nobel prize for that work in 1937. 

Biochemistry.  Vitamin C is also known as ascorbic acid or ascorbate.  It is water soluble and easily absorbed, primarily in our small intestine.  Interestingly, most mammals make their own Vitamin C from glucose!  But primates - including humans - guinea pigs, fruit bats and a few birds are lacking the last enzyme in the necessary synthesis pathway to accomplish this for themselves.  Thus we are relegated to a lifetime requirement of dietary intake of Vitamin C.  It is easily absorbed and distributed throughout the body, but does concentrate in the adrenal and pituitary glands and in white blood cells. 

Functions.  Vitamin C serves many important functions in the body. 
Collagen formation requires ascorbic acid in two separate reactions.  Collagen is a component of cartilage, dentin, skin, blood vessels and bones, especially in our growing stages.  Carnitine synthesis also requires Vitamin C in two reactions.  Carnitine is required for fat metabolism.  Ascorbic acid is also necessary for the synthesis and/or catabolism of tyrosine, a few neurotransmitters and some adrenal and pituitary hormones.  Vitamin C has solid anti-oxidant activity, helping to prevent, reduce and repair oxidation damage.  It appears to have some working relationship with Vitamins E and A and glutathione and it increases the absorption of iron.  It is believed to have other roles in the body as well and is still being studied for effects in cardiovascular disease, cancer, gout, depression, diabetes, immunity and healing, cataracts and more. 

Deficiency.  Severe Vitamin C deficiency causes scurvy and can be fatal, as mentioned above.  Symptoms of scurvy include fatigue, easy bleeding/bruising, loss of hair and teeth, joint pain.  While scurvy is rare today, there are certain populations or conditions that deplete Vitamin C quickly and are at risk for problems associated with lower levels.  These include those with poor diets, especially when coupled with advanced age, alcoholism or drug abuse.  Smokers have significantly lower levels of Vitamin C and extreme, chronic stress can also deplete Vitamin C. 

Toxicity.  Vitamin C is generally considered to be very safe.  However, part of the Vitamin C controversy focuses on its toxicity.  There is some theoretical concern, but no convincing study, about high doses causing kidney stones and being problematic for people with iron overload issues.  In 2000, an Upper Limit of 2000 mg/day was established.  This was in part because amounts higher than this can cause diarrhea in some people. 

Sources.  We all tend to think first of oranges as our primary source of Vitamin C.  And oranges are, indeed, a good source.  But they aren't the only, or even the best source!  Virtually all our fruits and vegetables have some Vitamin C.  A few that are higher than oranges include red bell peppers, papaya, brussel sprouts, strawberries and broccoli.  It is always best to use food as our medicine and this is the very best way to get your vitamins!  Eat up and enjoy!

Therapeutic Use.  The current RDA for Vitamin C is 75-90 mg/day for a healthy adult.  That amount is higher (110-125mg/day) for smokers.  In those healthy adults, this is certainly adequate to prevent scurvy.  But is preventing scurvy the only reason to take Vitamin C?  Herein lies the rest of the Vitamin C controversy.  Is this vitamin useful in higher doses?  If so, for what and how high?  Linus Pauling, the only person to win 2 unshared Nobel prizes, was an advocate of high dose Vitamin C.  He not only used high oral doses, but also used Vitamin C in IV therapies.  It is still used this way in certain situations.  (But it is not something a naturopathic doctor can do in Michigan.)  The Linus Pauling Institute at Oregan State University continues to study vitamins and minerals and their effects on health.  You can read more at this link: Linus Pauling Institute.  But even using lesser doses, dozens of conflicting studies have been done considering Vitamin C and the common cold.  You may belong to the "swear-by-it" camp or the "it's-hooey" camp and find studies to support your view.  The same goes for its use in cardiovascular disease and cancer.  Some of the claims for the value of Vitamin C are based on our understanding that a diet high in fruits and vegetables is associated with lower incidences of many diseases and conditions - and these foods are high in Vitamin C.  Some of them are based on comparisons with other mammals that make their own.  Studies done with rats and dogs show they make a human-equivalent of 2-4 grams/day under normal conditions.  Under stressed conditions, rats, goats, dogs, and guinea pigs make up to 15 grams/day!  Even in human studies where no difference is shown in healthy subjects, those who are under some sort of stress do appear to receive a benefit from Vitamin C. 

So what is the bottom line on Vitamin C?  Well, adults need to have AT LEAST 75 mg/day, preferably from their diet.  If you are a smoker, that goes up to AT LEAST 110 mg/day.  Those are the "official" recommendations. Most would also agree that if you are using birth control pills (known to deplete Vitamin C) or if you are working on some wound healing (known to require Vitamin C), it would be prudent to raise that amount.  Remember the "official" upper limit is 2000 mg/day, so no adverse effects are expected up to that dose.  And remember, too, that limit is for supplemented Vitamin C.  There is no upper limit on the Vitamin C you get from your regular diet!  But for those who are want to try supplementing higher doses in times of cold/flu or high stress or wound healing, it is reasonable to find your personal upper limit based on what is called bowel tolerance.  Starting at the 2000mg/day, increase the dose by 500-1000 mg/day until your stools are loose.  If they're too loose, that's your bowel tolerance and you'll want to go back to the next lowest dose.  You may find that this limit changes based on the individual features of a particular day.  Some people can double or triple their usual dose when they're under a lot of stress or coming down with a cold. 

Two additional points.  * If you're taking more than 500-1000 mg, it is best to use divided doses.  That is, take smaller amounts multiple times in the day - 250 mg at breakfast, lunch and dinner, for example.  * If you find Vitamin C bothers your stomach (it IS ascorbic acid after all), you may find that buffered Vitamin C will treat you better.