Scallions are very low-calorie ingredients that can add subtle flavor to your recipes. Below are the basic nutrition facts for one medium scallion, about 15 grams. The percentages are your daily recommended value for a 2,000-calorie diet. Calories: 5 Total fat: 0 Cholesterol: 0 Sodium: 2 milligrams, 0% Potassium: 41 milligrams, 1% Total carbohydrates: 1.1 grams, 0% Dietary fiber: 0.4 grams, 1% Sugars: 0.3 grams Protein 0.3 grams, 0% Vitamin A: 3% Vitamin C: 4% Calcium: 1% Iron: 1%