Organic Red Kale. The red sister variety of the market standard curly green kale, curled, red leaves.  As with all red kales, flavor and color are enhanced by cold weather. The nutrients in kale can help boost wellbeing and prevent a range of health problems. It contains fiber, antioxidants, calcium, and vitamin K, among others. Even the chlorophyll in kale may have health benefits. It is also a good source of vitamin C and iron.