They are also best for your health and provide strong immunity. Dark green veggies are the best source of minerals like magnesium, iron, calcium, and potassium. Also work as strong antioxidants and best for your health. Great source of vitamins like E,C, K, and b vitamins. Raw 100g leafy vegetables contain only 23 calories, 3.6g carbs, and 2.2g fibers.