What causes low ferritin levels?

Low ferritin levels indicate iron deficiency, says MedicineNet. When iron levels are low, the body struggles to produce hemoglobin, a protein in red blood cells that allows them to carry oxygen, notes Mayo Clinic. This leads to iron deficiency anemia.

Iron deficiency anemia can occur when the body loses more blood cells and iron than can be replaced, according to MedlinePlus. It may also occur when the body is unable to absorb iron or if a person's diet lacks iron-rich foods.

Treatment involves supplementation with iron, notes MedlinePlus, and eating an iron-rich diet. Some doctors also advise increasing intake of vitamin C to increase iron absorption, says Mayo Clinic.