As per USDA National Nutrient Database, raisins are a good source of energy, fiber, protein, and carbs. They are also rich in potassium, vitamin C, calcium, magnesium, phosphorus, and sodium. They contain vitamins and minerals such as thiamin, niacin, riboflavin, vitamin B-6, iron, and zinc. Raisins are high in sugar and calories but have a low glycemic index. They contain zero cholesterol.