Should Endurance Athletes Take Vitamin C Supplements?

In 2010 I want to A) train harder, B) get leaner, C) go faster, and do all of this while D) remaining healthy.

Thanks to Coach Lynda, I have the “train harder” part nailed. The “get leaner” part is up to me and my ability to resist Michelle’s incredible baked goodies which seem to magically appear in a perfectly timed succession so as to ensure that there is always something tempting and delicious on the kitchen counter. If I nail A and B, the result will be C. But how can I ensure D? There is nothing fun about getting sick and even a simple cold can derail your training for a week or more.

In the past I have increased my dosage of Vitamin C during and/or immediately following big training blocks. Why? Because “they” say it is the right thing to do. But I recently asked myself, "Who are 'they' and when did this become an accepted practice?"

Where it all began
From the Article “Vitamin C: Do High Doses Prevent Colds?” by Charles W. Marshall, Ph.D.

Few things have stirred the imagination and hopes of the public in matters of nutrition or vexed nutrition scientists as much as Linus Pauling's 1970 book, Vitamin C and the Common Cold. The book's main claim was that taking 1 gram (1,000 mg) of vitamin C daily would reduce the incidence of colds by 45% for most people, but that some persons might need much larger amounts. It recommended that if symptoms of a cold do start, you should take 500 or 1,000 mg every hour for several hours -- or 4 to 10 grams daily if symptoms don't disappear with smaller amounts. Without question, publication of this book, combined with Pauling's reputation as a Nobel Prize-winning scientist, has made vitamin C a best seller. When his theory was announced, millions of Americans rushed to try it for themselves.

Many concerned persons have wondered whether Pauling's advice was prudent, and millions have experimented upon themselves to see whether they could tell. Pauling himself reportedly took 12,000 mg daily and raised it to 40,000 mg when symptoms of a cold appeared! Pauling apparently adapted to such dosage, but most people would suffer chronic diarrhea and the risk of kidney stones. Also, the vast majority of reputable medical and nutritional scientists strongly disagree with him.

In addition to taking basic Vitamin C in larger doses, I have been lured in by the various “immunity products” such as Airborne and Emergen-C which are all based on 1000mg doses of Vitamin C. Vitamin C increases your immune system’s defenses right? Not so fast my friend. A little digging around revealed some interesting articles.

This study suggests that Vitamin C does nothing to prevent illness following a big effort.

This article suggests that Oral Vitamin C prevents improvement in VO2 max and endurance capacity.

These are just two articles in a sea of thousands but it is enough to leave me questioning my previous practice. More digging to follow...