Iron is a vital component of heme, the component of hemoglobin that transports oxygen in the blood. Iron deficiency is the world's most common cause of anemia (blood with low hemoglobin and red blood cell components). While some plants have modest amounts of iron (e.g., spinach), meat (red or white) has many times more iron than plants. Meat iron is also absorbed much more efficiently than plant iron. In addition to oxygen transport, iron and heme are key to normal brain development. Iron deficiency during the first six months of life can irreversibly impair cognitive development.
KENNETH R. BRIDGES
Bridges, K. R. (2000). "Iron Deficiency." In Coun's Current Therapy, ed. R. E. Rakel. Philadelphia, PA: W. B. Saunders Company.