I think this ingredient is designed to throw people for a loop. It is in Vitamin Water and it is a cleverly disguised corn bi-product. (http://en.wikipedia.org/wiki/Crystalline_fructose) Just some preliminary research claims this stuff is not cool. Please visit corn.org to learn more about how HFCS is made.
I understand that HIgh Fructose Corn Syrup (HFCS) can be manufactured to either contain equal amounts of fructose and glucose, or up to 80 percent fructose and 20 percent glucose." Fructose and glucose are metabolized differently in the body. "Glucose is metabolized in every cell in the body, however all fructose must be metabolized in the liver. That's why fructose can create a fatty liver or lead to cirrhosis of the liver. Crystalline fructose "is produced by allowing the fructose to crystallize from a fructose-enriched corn syrup." This information is from the sugar producers themselves, at sugar.org. Crystalline Fructose contains 99.5% minimum of fructose assay, which is an even higher percentage of fructose than what makes up HFCS. Another ingredient of crystalline fructose is arsenic. I don't know about you, but I don't care what the amount is (in this case the chemical specs state 1 mg/kg maximum), I don't want to be ingesting arsenic. it also contains chloride, heavy metals and lead as reported in a pdf document from admworld.com
I ran across some interesting information about 23 "health" drinks that have crystalline fructose in them including vitamin water. Click on the following link to find out if you are drinking any of these.