How Things Work: Red Blood Cells

When we draw blood for a complete blood count, what are we actually counting? About 55% of our blood is made up of plasma, comprised of water, proteins, electrolytes, nutrients, and hormones. The other 45%, or the part that we count, is comprised of White Blood Cells—our immune cells, platelets—cells that make the blood clot, and red blood cells (RBCs), which are required to transport oxygen from the lungs to our tissues and carbon dioxide from the tissues back to the lungs.

Because they are responsible for bringing nutrition to and wastes from the entire body, when RBCs are low, a condition called anemia, it is easy to understand why one would experience the symptoms mentioned in Iron Ironies. Blood gases are carried in RBCs via hemoglobin which is contained in the RBCs. Hemoglobin is made of proteins that fold around a central heme molecule with an atom of Iron in the center, which gives the cell its red color. RBCs are formed primarily in the bone marrow of the sternum, ribs, vertebrae, skull, and pelvis, although the femur, tibia, liver, and spleen also have the ability to make RBCs. Causes of anemia include nutritional deficiencies, chronic disease, and chronic blood loss.

Good nutrition is integral for formation of RBCs. Deficiencies in Iron, which functions as noted above, or Copper, which is necessary for transporting iron to the blood marrow, will create cells that are too small. The B Vitamins B12 and Folic Acid are necessary for making DNA and influence cell division; deficiencies in these will cause large, immature cells to be released into the blood. Vitamin C enhances absorption and utilization of Iron, Copper, B12, and Folic Acid. In particular, it enhances intestinal absorption of Iron, particularly from vegetarian sources, and thus is of particular importance for those choosing not to eat meat.