Spinach is the star in this creamy smoothie, and for good reason — with just one 16-ounce serving, you'll be getting your entire Recommended Dietary Allowance of vitamin A (great for healthy skin, hair, and eyes) and bone-building vitamin K, as well as an impressive amount of essential nutrients like manganese, potassium, and vitamin C. This 300-calorie smoothie is a good source of protein, making this veggie-packed smoothie a smart breakfast choice, especially if you're trying to lose weight.