a bit of info

Vegetables in general do not tend to be rich in iron, however some garden greens are calcium-rich. 
Vegetables on the whole are a poor source of calcium, but some leafy greens do contain a good dose. 
Spinach, kale, and turnip greens are solid foods for calcium. 
Always remember that Collards, spinach, and kale are widely available greens that are high in calcium.
Carrots contain 33 milligrams of calcium per 100 grams.

What is kale? What is the other name of kale?
 Kale or borecole (Brassica oleracea Acephala Group) is a vegetable with green or purple leaves, in which the central leaves do not form a head. It is considered to be closer to wild cabbage than most domesticated forms.
Kales can be classified by leaf type:
Curly-leaved (Scots Kale)
Plain-leaved
Rape kale
Leaf and spear (a cross between curly-leaved and plain-leaved kale)
Cavolo nero (also known as black cabbage, Tuscan Cabbage, Tuscan Kale, Lacinato and dinosaur kale)
Because kale can grow well into winter, one variety of Rape Kale is called Hungry Gap, named after the period in winter in traditional agriculture when little could be harvested.
An extra tall variety is known as Jersey kale or cow cabbage.
. Tender kale greens can provide an intense addition to salads. Many varieties of kale and cabbage are grown mainly for their ornamental leaves. It is considered to be closer to wild cabbage than most domesticated forms.