Yu choy is very nutritious, low in calories, and high in fiber, vitamins, and minerals. A 100-gram serving of raw yu choy provides the following nutritional values: Calories: 24. Protein: 2 grams. Carbohydrates: 4 grams. Sodium: 24 milligrams. Yu choy provides the following recommended daily allowances: Vitamin A: 200%. Vitamin C: 21%. Calcium: 24%. Iron: 9%. Keep in mind that when you add oil or sauces with sodium in them, these nutritional values will change slightly.