@feruze-- Actually, the vitamins and antioxidants in rose hip start to lose quality as soon as they are taken off of the plant.
I think it's more beneficial to simmer rose hips on low heat in water and make a syrup out of it where the water is also used. Most of the vitamin C from the rose hips will remain in the water. If you also add some ascorbic acid to the syrup, then you will end up with a super-food.
I've been making my own rose hips syrup for years. Rose hips are great for fatigue and for preventing the common cold.