From the Guidelines
Low ferritin levels are primarily caused by iron deficiency, which can result from inadequate dietary iron intake, poor iron absorption in the digestive tract, or blood loss. According to the most recent study 1, common sources of blood loss include heavy menstrual periods in women, gastrointestinal bleeding from ulcers or inflammatory bowel disease, and frequent blood donations. Certain medical conditions like celiac disease, Helicobacter pylori infection, or gastric bypass surgery can impair iron absorption, as noted in 1. Pregnancy increases iron requirements and can deplete ferritin stores. Some medications, including proton pump inhibitors and certain antibiotics, may interfere with iron absorption. Chronic inflammatory conditions can also affect iron metabolism, leading to functional iron deficiency despite adequate iron stores, as discussed in 1.
Causes of Low Ferritin
- Inadequate dietary iron intake
- Poor iron absorption in the digestive tract
- Blood loss from heavy menstrual periods, gastrointestinal bleeding, or frequent blood donations
- Medical conditions like celiac disease, Helicobacter pylori infection, or gastric bypass surgery
- Pregnancy
- Certain medications like proton pump inhibitors and antibiotics
- Chronic inflammatory conditions
Diagnosis and Treatment
Treatment typically involves oral iron supplements such as ferrous sulfate 325mg taken 1-3 times daily between meals with vitamin C to enhance absorption. For severe deficiency, intravenous iron may be necessary, as recommended in 1. Dietary changes to include iron-rich foods like red meat, spinach, beans, and fortified cereals can help maintain adequate ferritin levels long-term. It is essential to monitor laboratory parameters, including ferritin and transferrin saturation, to assess the response to treatment and adjust the frequency of administration accordingly, as suggested in 1.
Monitoring and Management
- Laboratory evaluation following IV iron should include a CBC and iron parameters (ferritin, percent transferrin saturation) 4 to 8 weeks after the last infusion
- Hemoglobin concentrations should increase within 1–2 weeks of treatment and should increase by 1 to 2 g/dL within 4–8 weeks of therapy
- The goal ferritin is 50 ng/mL, regardless of sex at birth, in the absence of inflammation, as stated in 1
From the Research
Causes of Low Ferritin
- Iron deficiency anemia is a common cause of low ferritin levels, as ferritin is a protein that stores iron in the body 2
- Chronic diseases, such as chronic kidney disease (CKD), can also lead to low ferritin levels due to inflammation and impaired iron regulation 3, 4
- Insufficient iron intake or poor iron absorption can contribute to low ferritin levels 4
- Certain medical conditions, such as celiac disease or Crohn's disease, can impair iron absorption and lead to low ferritin levels
Diagnosis and Treatment of Iron Deficiency
- Serum ferritin concentration is a commonly used diagnostic test for iron deficiency, with a cutoff of 100 μg/L often used to indicate iron deficiency 4
- Transferrin saturation (TSAT) is also used as a diagnostic test, with a threshold of 20% often used to indicate iron deficiency 4
- Treatment of iron deficiency typically involves iron supplementation, either orally or intravenously, depending on the severity of the deficiency and the presence of underlying medical conditions 3, 4, 5