How is iron classified? How much iron is in the body, in total? Specifically, where is iron distributed within the body, and how much is in each 'compartment'? Further, what is typical iron consumption in a day, and how much is actually absorbed? Also, what is considered the target level of serum ferritin, and what is considered low serum ferritin levels? Finally, what is a strategy (consumption and time) to replenish low serum ferritin levels