It's generally known that boiling vegetables removes a large fraction of vitamin C, but in what way?  Does the high temperature destroy it?  Is it merely absorbed by the boiling water? 
Actually, vitamin C degrades with heat. The following, by dietician Jill Irvin, says it all:     Vitamin C is one of the least stable of all vitamins in solution   and is oxidized readily in light, air and when heated. It is also    water soluble. This means that heating in water, (like cooking    broccoli in boiling water) causes the vitamin to leach out of the   food into the water and also to be oxidized, first to dehydroascorbic   acid and then to diketogulonic acid. This last compound has no Vit[amin] C   activity at all and is irreversible.   She goes on to say that normal cooking doesn't affect levels of the vitamin too much, but the main issue being queried here is how boiling removes vitamin C from food, and this quotation tells how that happens. 