Grapes are high in several important nutrients. One cup (151 grams) of red or green grapes contains the following nutrients (1): Calories: 104 Carbs: 27.3 grams Protein: 1.1 grams Fat: 0.2 grams Fiber: 1.4 grams Vitamin C: 27% of the Reference Daily Intake (RDI) Vitamin K: 28% of the RDI Thiamine: 7% of the RDI Riboflavin: 6% of the RDI Vitamin B6: 6% of the RDI Potassium: 8% of the RDI Copper: 10% of the RDI Manganese: 5% of the RDI One cup (151 grams) of grapes provides more than a quarter of the RDI for vitamin K, a fat-soluble vitamin vital for blood clotting and healthy bones They are also a good source of vitamin C, an essential nutrient and powerful antioxidant necessary for connective tissue health