An important nutrient would be beta carotene, which the body uses to make Vitamin A.
yes because it's in most vegetables like lettuce and spinach(etc).
strach
fat
Heroin.
carrots and squid rings also a bit of spinach juice
Liver, red meats, spinach and other green leafy vegetables and grapefruit are sources of iron. It is also added to many breakfast cereals. You can also get it from chocolate!
Yes. all plants contain chloroplasts.
No. I have a nightshade allergy and spinach does not make me sick; I have another friend with a similar allergy who can also eat spinach. Most lists of nightshades I have found online do not contain spinach; https://secure.wikimedia.org/wikipedia/en/wiki/Spinach does not list Solanaceae.
Leaves are eaten in spinach. These are fleshy, green and contain lots of iron.
iron
Yes.
Spinach juice is not but an acid may contain some acids (eg. oxalic acid), more than base.