The question of how to increase ferritin levels sounds simple — take iron — but the details decide whether supplementation works: whether the deficiency is real, what caused it, how much iron is taken, how often, at what time of day and for how long.
Iron deficiency is one of the leading contributors to the global burden of disease. A 2025 JAMA review estimated that absolute iron deficiency, meaning low iron stores with or without anemia, affects approximately 2 billion people worldwide and 14% of adults in the US.
Estimates of iron deficiency in female athletes reach up to 60%, and in high-level iron-deficient female athletes endurance performance was negatively affected by 3%–4%.
The honest answer is that “normal” depends on the context. Normal iron levels for athletes are not always the same thing as normal iron levels for the general population, because standard laboratory ranges are not specifically built around competitive endurance training.
Iron deficiency is one of the most prevalent nutritional problems in sport — yet many of my patients who diligently take iron supplements are unknowingly undermining their own treatment.
Iron deficiency is common in athletic populations, with higher rates observed in female athletes and endurance disciplines.
Patients often ask me about their iron levels. Most are familiar with ferritin, as it has become something of a “trend” lab test, while others are curious about additional components of the iron panel, such as serum iron.
Interpreting iron status in athletic patients is often more complex than in the general population. Ferritin, in particular, behaves differently in physically active individuals, and the physiological effects of training can significantly complicate its interpretation.
Most athletes who get their blood work done know to look at ferritin and hemoglobin, but fewer understand how to interpret TIBC in athletes.
Ferritin is a laboratory test that measures the body’s iron stores. The lower limit of the standard reference value for ferritin in standard laboratories is typically 15 ng/mL.
From time to time, some of my athletic female patients complain of prolonged fatigue and an unexplained decline in athletic performance.
