The kidneys produce a substance that helps with the creation of new red blood cells. (kerryblues.org)
As the red blood cells age or become damaged, they are removed from the circulation and their contents will be recycled to form new red blood cells. (cedarbayouanimalclinic.com)
Iron is needed to make new red blood cells to support your blood volume, which doubles during pregnancy. (healthyeating.sfgate.com)