Iron
Iron is an element (chemical symbol: Fe) that is important for the forming of blood. It is in relatively great quantities in many vegetables, especially leaf vegetables. Among the fruits the Inca berry has relatively much iron. Meat, especially liver, has a lot of iron.
To support the resorption of iron, take the vegetables together with an acid like vinegar. Avoid to take them with milk (except maybe sour milk) because it inhibits the resorption. This is probably why some peoples have a tradition not to take milk and meat during the same meal.
