A lack of iron may increase the risk of dangerous blood clots, according to new research.
The findings suggest iron supplements might be a way to prevent Deep Vein Thrombosis (DVT) and other types of potentially life-threatening clot.
Each year, one in 1,000 people in the UK is affected by clots that form in the veins, usually the legs.
DVTs are often associated with long distance air travel and other situations that involve being immobile for extended periods of time.
British scientists looking for new blood clot risk factors studied 609 patients with haemorrhagic telangiectasia (HHT), an inherited disease of the blood vessels. Previous research had shown that HHT patients have a higher risk of blood clots, though the reasons were unclear.
Symptoms of HHT include excessive bleeding from the nose and gut, resulting in a loss of iron.
The study, published in the journal Thorax, showed that many of the patients had low iron levels because of iron loss through bleeding.
They also had a higher risk of blood clots, which disappeared when they took iron supplements.
A blood-iron level of six micromoles per litre compared with the normal mid-range figure of 17 micromoles led to a 2.5-fold increase in venous thrombosis risk.
“Our study shows that in people with HHT, low levels of iron in the blood is a potentially treatable risk factor for blood clots,” said lead researcher Dr Claire Shovlin, from the National Heart and Lung Institute at Imperial College London.