Iron is necessary not only to make red blood cells that carry oxygen but iron is also in the muscle fibres to enable oxygen to be converted to energy by aerobic metabolism. So iron is vital to general energy and power as well as aerobic fitness. Iron deficiency is the commonest nutritional disorder worldwide. Iron deficiency cause fatigue, tiredness, muscle aches as well as reduced mental and physical performance. Iron Deficiency leads to under performance in both mental and physical activities. In our work we showed a 15% improvement in performance once iron deficiency was treated in athletes.

The most common cause of iron deficiency in women is the menstrual cycle

The most common cause of iron deficiency in women is the menstrual cycle

The female vegan athlete is at high risk of iron deficiency for four reasons: -

Iron is absorbed from the gut (the duodenum just after the stomach) by two mechanisms. There is a specific Haem (meat iron) carrier protein and also a more general metal transporter. The latter requires iron to be in the correct form (ferrous not ferric) and absorption is aided by vitamin C. To put this in perspective you need about 1kg of spinach (a bin bag full) to gain the same amount of iron as a small hamburger (100g).

The commonest cause of iron deficiency in women is the menstrual cycle, particularly those with heavy periods. In a study of over 1000 women undertaking the London Marathon we found that one third of athletes had heavy menstrual bleeding, this was just as common in elite runner as the Sunday jogger. Indeed when we tested athletes iron levels 28% of those with heavy period had iron deficiency and anaemia as opposed to 10% who did not. A three-fold difference.

The Skin is very rich in iron. Indeed iron deficiency is a common reason for poor hair of hair loss. Iron is lost in the sweat so athletes need about 60% more iron to make up for these losses.

Finally, after exercise the muscles are tired and can be inflamed, this is why your legs hurt! The body regards this inflammation in a similar manner to illness. The key protein responsible for iron metabolism, Hepcidin, reduces iron. This is why rest days are so very important.

Becoming a vegan is an individual's choice. For an Athlete they need to be very careful and if iron deficient then an iron infusion will enable the above pathways to be bypassed, delivering the iron direct to the bone marrow and muscles enabling a return to performance in a couple of weeks.


Dr Andrew Klein is a Consultant Anaesthetist at Spire Cambridge Lea Hospital. He has a long interest in anaemia management and was one of the first clinicians to highlight the problems of anaemia in patients undergoing surgery.  He has lead ground breaking work into the diagnosis of iron deficiency in patients with anaemia highlighting the need for intravenous iron therapy.

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