The solid part of your blood contains red blood cells, white blood cells, and platelets. Red blood cells (RBC) deliver oxygen from your lungs to your tissues and organs

Red blood cells will circulate in the body for an average of 100–120 days. After this, they go to the liver, where they are broken down, and their nutrients are recycled back into the cells.

Red blood cells are continuously produced in the bone marrow. If the body does not receive a regular supply of necessary nutrients, the red blood cells may become malformed or die off at a faster rate than the body can replace them.