Iron balance and iron supplements in female athletes
What it found
Iron deficiency is common in female athletes, especially those with heavy periods, and can hurt endurance performance.
Iron injections and oral supplements both work for iron deficiency anaemia, but whether treating milder iron deficiency helps is still unclear.
What they found
Studies in people
Heavy periods and iron loss
Menstruating women lose about 1 mg of iron a day when bleeding. In heavy menstrual bleeding, blood loss is estimated to be 5 to 6 times greater, and this affects 1 in 3 athletes at all levels.
Iron deficiency and performance
Female rowers with iron deficiency without anaemia had 21 second slower 2 km time trial times than those with normal iron. They also trained less each week.
Iron treatment for anaemia
In athletes with iron deficiency anaemia, iron treatment raised iron stores, total haemoglobin mass and red cell measures, and improved aerobic power. A mean rise in total haemoglobin mass of 11% was seen after 12 weeks of oral supplements.
Milder iron deficiency
Studies in female athletes with iron deficiency but no anaemia have been mixed. Some found no change in aerobic power after iron treatment, while one study found a likely improvement in VO2max after iron injections but not oral supplements.
Animal and lab studies
Iron overload in animals
In animal studies of iron overload, signs of damaging free radical activity rose in the liver, kidney and plasma after iron was given. A link between iron overload and diseases including cancer has also been reported.
Other findings
Testing iron status
Haemoglobin and serum ferritin are used together to spot iron deficiency, but each can be misleading in athletes. Training, altitude, inflammation and individual differences can all affect the readings.
What the authors conclude
“Questions remain over the impact of IDNA and whether or not iron treatment is appropriate for this condition.”
Also in their conclusions
- They say iron deficiency anaemia reduces endurance performance by harming oxygen transport and should be treated by a doctor.
- They advise that iron injections and oral supplements are effective treatments for iron deficiency anaemia.
- They call for controlled studies on dietary iron in female athletes that account for hormones, menstrual blood loss, training and environment.
How it was done
Iron deficiency is one of the most common deficiencies in sport, and female athletes are at particular risk because of menstruation. The authors wanted to give practical advice on spotting and correcting iron deficiency in these athletes.
The authors reviewed existing research on iron balance and iron supplementation in female athletes. They looked at studies covering training, diet, altitude, menstruation, pregnancy, blood tests and iron treatments.
What it can’t tell you
- This is a review of other studies, not a new experiment, so it cannot prove cause and effect.
- The studies it covers used different doses, tests and groups of athletes, which makes them hard to compare.
- The long-term effects of taking iron supplements are not known.
Who paid
- Authors work at
- St Mary's University, UK; Massachusetts General Hospital, USA; Boston Children's Hospital, USA
The paper
- Title
- Iron balance and iron supplementation for the female athlete: A practical approach
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Pedlar CR, Brugnara C, Bruinvels G, Burden R (2018). Iron balance and iron supplementation for the female athlete: A practical approach. European journal of sport science. doi:10.1080/17461391.2017.1416178Free full textPubMed 29280410DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error