Broccoli has large flower heads, usually dark green, arranged in a tree-like structure branching out from a thick stalk which is usually light green. The mass of flower heads is surrounded by leaves. Broccoli resembles cauliflower, which is a different but closely related cultivar group of the same Brassica species. Broccoli is a good source of vitamin K and calcium, two vital nutrients for maintaining strong, healthy bones ( 42 , 43 , 44 ). It also contains phosphorus, zinc and vitamins A and C, which are necessary for healthy bones as well (45).