Battle of the greens: Which is healthier, kale or spinach?

(Natural News) Kale and spinach are two of the healthiest superfoods. But is one better than the other? Nutritional differences between kale and spinach Kale and spinach are both nutrient-rich and low-calorie vegetables. They also offer many essential vitamins and minerals. Both are rich in vitamin K, a nutrient needed for healthy blood clotting and bone...