Kale powder is the dried, ground form Kale, a cruciferous vegetable like cabbage, broccoli, cauliflower, collard greens and Brussel sprouts. It is considered to be one of the most nutrient-dense foods as contains many powerful antioxidants including quercetin and kaempferol, in addition to vitamins A, C, K and B6, the minerals manganese, copper, calcium and magnese, and various flavonoids and polyphenols.