Green leafy vegetables are added to diet as they contain minerals and vitamins. Minerals like calcium are present due to which formation of bones and teeth takes place. Calcium also helps in muscle movement by muscle contraction and blood clotting after injury. Vitamins like .A. and .D. are present. It contains cellulose which is not digestible by human beings. This acts as dietary fibre or roughage and it helps in easy absorption of nutrients, easy movement of bowel and prevents constipation.