The blood that circulates throughout the body performs a number of critical functions. It delivers oxygen, removes carbon dioxide, and carries life-sustaining nutrients. By transporting long-distance messengers such as hormones, blood helps the various parts of the body communicate with each other. This is carried out by blood cells, working in partnership with the liquid part of the blood (plasma). Most of the cells that make up your blood are red blood cells (erythrocytes). White blood cells (leukocytes) are also present, defending the body against foreign material, including infections, viruses, and fungi.
Anemia occurs when there isn't enough hemoglobin (an iron-protein compound in red blood cells that transports oxygen) in the blood and there are too few red blood cells. Anemias are the most common blood disorder; there are several types of anemia. They are usually caused by an iron deficiency. Based on the most recent study conducted in 2011, only approximately 3% of Canadians have anemia (including all forms of anemia). However, 9% of women aged 20 to 49, and 13% of females aged 12 to 19 have iron-deficiency.
Some infants may need extra iron, especially if they are bottle-fed with cow's milk. This is why doctors often prescribe iron supplements during infancy and why infant diets are iron-fortified and only iron-fortified formulas should be used.