From the Guidelines
Iron supplementation is recommended for female athletes with iron deficiency or those at high risk, with a typical dosage of ferrous sulfate 325mg once daily for iron deficiency without anemia and 325mg twice daily for iron deficiency anemia, as supported by recent guidelines 1, 2.
Key Considerations
- Female athletes are at a higher risk of iron deficiency due to menstrual blood loss, inadequate dietary iron intake, and increased iron losses through sweat and hemolysis during intense exercise 3.
- Iron deficiency can lead to fatigue, decreased performance, and impaired recovery, making it essential for athletes to maintain adequate iron levels 1.
- Dietary sources of iron, particularly heme iron from meat and seafood, should be emphasized alongside supplementation when needed, with vitamin C co-ingested to enhance absorption and avoidance of foods that inhibit absorption like tea and coffee 3.
Monitoring and Treatment
- Regular monitoring of iron status through blood tests is crucial, with a reasonable time frame for assessment being once per year in male players and twice per year in female players 3.
- Treatment strategies depend on the severity of disease, with conservative therapy involving increased dietary intake and oral supplementation of iron, and parenteral supplementation reserved for special cases like severe deficiency or enteral absorption disruption 2.
Side Effects and Management
- Side effects of iron supplementation may include constipation, nausea, and dark stools, which can be managed by taking supplements with food or adjusting dosage 3.
- Athletes should be aware of the potential for pseudoanemia, where iron studies indicate anemia but laboratory values are a result of expanded plasma volume, and consult a sports dietitian to optimize their daily nutrition plans for iron intake 1.
From the Research
Iron Supplementation in Female Athletes
- Iron deficiency is a prevalent issue among female athletes, particularly those participating in endurance sports, due to increased iron losses through menstruation and exercise-induced mechanisms 4, 5, 6.
- Iron status can be assessed using indicators such as hemoglobin and serum ferritin, but clinical cut-offs for active populations remain controversial 4, 7.
- Randomized, placebo-controlled supplementation trials have shown that oral iron supplementation in doses of 100-mg FeSO4·d (approximately 20 mg elemental iron) can improve iron status and physical performance in iron-depleted female athletes 4, 8.
- Dietary modification, such as consuming an iron-rich diet or haem iron-based diet, can also assist in maintaining iron status in female athletes, especially during intensive training and competition 5, 7.
Effects of Iron Deficiency on Sports Performance
- Iron deficiency can negatively affect endurance performance in female athletes, with declines in physical performance ranging from 3-4% 8.
- Iron deficiency can also impede isokinetic strength and anaerobic power performance, with effects ranging from -23% to +4% 8.
- Supplementation with 100 mg/day of elemental iron can improve endurance performance by 2-20% and maximal aerobic capacity by 6-15% in iron-deficient female athletes 8.
Supplementation Recommendations
- Female athletes at risk of iron deficiency should be screened at the beginning of and during the training season using hemoglobin and serum ferritin, and appropriate dietary and/or supplementation recommendations should be made 4, 7.
- Supplementation with 100 mg/day of elemental iron is recommended for iron-deficient female athletes, with improvements in endurance performance and maximal aerobic capacity observed after 16-126 days of supplementation 8.