As vegetables go, leafy greens—especially the dark-green kind—tend to top health experts' lists. And, along with spinach, kale is at the top of the dark-and-leafy-green heap. Bursting with vitamins A, K, and C, kale is also a great source of calcium, iron, magnesium, and potassium. Whether you toss it into soups, smoothies, or salads, gobble as much of this stuff as you can every day.