That is vitamin C, whether you extract it from rose hips, oranges or if I make it in a lab. There is no difference between vitamin C from genetically modified food, organic food or if it's cooked up in a lab. You see, vitamin C has zero genetic material. It is a clearly defined molecule and all other substances, in a good quality supplement, are removed.
So, that said, what is possibly legitimate to be concerned about is what other fillers or bulking agents are used in your supplement of choice. Check the label. The only difference to your body in taking it in supplement form, is that food acts as a time-release agent. The body gets rid of vitamin C quickly, so to emulate a more natural mode of uptake, take small amounts all during the day.
Be smart, don't waste your money. There are some foods that are worth the extra money to buy organic (milk, lettuces and others), there are some that make no sense to buy organic (bananas, oranges and others.)