From the Guidelines
Low ferritin levels with normal iron saturation and no anemia indicate early iron deficiency, and I strongly recommend addressing this condition to prevent progression to iron deficiency anemia and improve overall health and performance. According to the latest evidence from the British Journal of Sports Medicine 1, iron deficiency, even without anemia, can have negative implications for aerobic performance, particularly in athletes.
Key Points to Consider
- Low serum ferritin (<35 μg/L) is a marker for iron deficiency, even if blood hemoglobin values are normal 1.
- Iron deficiency can cause symptoms like lethargy, reduced performance, fatigue, hair loss, or reduced exercise tolerance, despite normal hemoglobin levels 1.
- A diet rich in iron, particularly red meat, is recommended to avoid the development of overt anemia and maintain sufficient levels of other hem-containing proteins/enzymes 1.
- Iron supplementation may be considered at levels above the RDA after consultation with qualified medical and dietetic practitioners, especially in cases of inadequate dietary intake or increased iron loss 1.
Recommendations
- Take an oral iron supplement, such as ferrous sulfate 325 mg once daily or ferrous gluconate 300 mg once daily, preferably on an empty stomach with vitamin C (like orange juice) to enhance absorption.
- Identify and address the underlying cause of iron depletion, which may include menstrual blood loss, dietary insufficiency, malabsorption, or occult bleeding 1.
- Continue supplementation for 3-6 months to replenish iron stores, then recheck ferritin levels to assess the effectiveness of treatment 1.
From the Research
Significance of Low Ferritin Levels
- Low ferritin levels with normal iron saturation and no anemia can be an indicator of iron deficiency without anemia, which is a common condition 2.
- Iron deficiency without anemia can cause non-specific symptoms and compromise immune response, physical capacity, and intellectual functions 3.
- The diagnosis of iron deficiency is typically based on serum ferritin levels and transferrin saturation (TSAT), but the criteria for defining iron deficiency are not universally agreed upon 4.
Diagnostic Criteria
- Current guidelines define iron deficiency as a serum ferritin level <100 ng/ml or a TSAT <20% if the serum ferritin level is 100-299 μg/L, but these criteria may not be supported by clinical evidence 4.
- A low TSAT, rather than serum ferritin level, may be a more reliable indicator of iron deficiency in certain populations, such as patients with heart failure 4.
- Reticulocyte hemoglobin content (CHr) is a promising marker for diagnosing iron deficiency and monitoring iron therapy, but its use is limited by the lack of standardized cutoff points 5.
Clinical Implications
- Iron deficiency without anemia can have significant clinical consequences, including impaired physical and cognitive function, and increased risk of cardiovascular events 3, 4.
- Oral iron supplements are often effective in correcting iron deficiency, but intravenous iron may be necessary in some cases, such as patients with chronic heart failure or inflammatory bowel disease 2, 6.
- Routine surveillance of serum ferritin and TSAT is advisable in at-risk populations, such as patients with inflammatory conditions, to detect and manage iron deficiency 6.