With the Chinese shutting down manufacturing plants to ease pollution for the Olympics, the world is now suffering a shortage of Vitamin C. China sold ascorbic acid on the world market at less than what it cost to produce it, driving out competition.
Now with their monopoly they were able to drive the price up from $3.50/kg to $22/kg. The problem is 4 of the 5 plants that make vitamin c are near Beijing and they had shut them down to ease pollution for the Olympics.
The only other manufacturer is in the Netherlands and they can't keep up with demand. Vitamin c or ascorbic acid goes in many things from bread to cosmetics and naturally supplements. Corn could be used but it has its own pricey problems as well.