" 

 :I'm all right with this WLU.  What the vitamin pushing crowd can't and won't explain is how a megadosage can actually translate into a consistent blood level that would have an effect.  The intestinal tract controls absorption of Vitamin C, so a steady state of blood levels of Vitamin C occurs at around oral intake of 30 mg per day.  Yes, 30 mg per day.  So, anything more than that does nothing but get passed in the feces (I suppose), or is absorbed when the blood level drops if you don't take a pill the next day.  The few studies that seem to indicate some in vitro toxicity of vitamin C to cancer cells would require extremely high blood levels of it, which would require IV use.  Is it possible that IV doses of 1200 mg of Vitamin C would prevent a cold?  I don't know.  But the risk benefit ratio is quite high, I would have to say that most people would reject even being involved in a trial.  Anyways, through all the bandwidth, we get to the place where we're all happy, which is Vitamin C does squat for colds.     "