“That little cup of kale also stokes up your B vitamins, and provides about 8 percent of the trace minerals—copper, magnesium, manganese and iron—which are often in short supply in the American diet, yet are indispensable for blood formation and bone health.”

Baltimore Sun

Kale is really good for you and is a fantastic way to get loads of vitamins and minerals in winter. It also has calcium, potassium, and phosphorous, among smaller amounts of other minerals.

Link

Kale, cabbage, kohlrabi, cauliflower and broccoli and Brussels sprouts are all variants of the same species. I wonder if the same holds for them.