Kale is very high in beta carotene, vitamin K, vitamin C, and rich in calcium and Manganese. Kale is a source of two carotenoids, lutein and zeaxanthin.
Kale, as with broccoli and other brassicas, contains sulforaphane (particularly when chopped or minced), a chemical with potent anti-cancer properties.
kale is also a source of indole-3-carbinol, a chemical which boosts DNA repair in cells and appears to block the growth of cancer cells.(See more at Wikipedia)