Iron needs of babies and children. Iron is a mineral that babies and children need for good health and development. Red blood cells contain hemoglobin, a protein that carries oxygen to all cells in the body.Our bodies need iron to make hemoglobin.Iron gives red blood cells their colour.ron needs of babies and children. Iron is a mineral that babies and children need for good health and development. Red blood cells contain hemoglobin, a protein that carries oxygen to all cells in the body. Our bodies need iron to make hemoglobin. Iron gives red blood cells their colour.