foreigngirl is right about orange juice having a lot of vitamin C however, the acidity of the orange juice will make your throat hurt even more.
If your throat hurts here is what you could do: Heat up some water for tea. Make yourself your favorite tea, or you can buy chamomile tea. On a regular size cup of tea add four drops of lemon juice and a tea spoon of honey. It will taste kind of funny, but the honey will coat your throat so that it doesn't hurt so much. Repeat as needed. Also, try not to talk, your throat needs resting. Good luck and I hope you feel better.
Gargle with warm water in which you have put a pinch of salt. The lining of your throat is normally a mild alkaline, but cold bacteria change it to acidic (which is why orange juice, though good for you, won't make a sore throat feel better). Salt is an alkaloid, so mild warm salt water returns your throat to the way it should be. You may have to do this several times a day.