Severe iron deficiency is the most common reason of anemia that can cause weakness, tiredness and feeling faint.

A recent study by Swiss researchers, issued in the Canadian Medical Association Journal, revealed that iron pills can also be effective for those women who have moderately low iron levels, too.

The researchers studied 198 women at reproductive age between 18 and 53 years with persistent fatigue. Half of the women were assigned to receive 80mg oral iron tablets every day, while the other half received sugar pills.

The women’s medical fatigue scores were measured before treatment and after 12 weeks after taking the medicine.

Dr Bernard Favrat, one of the researchers from the University of Lausanne in Switzerland, said that after 12 weeks of iron supplementation, the fatigue scores decreased by 50 per cent.

“Iron deficiency may be an under-recognized cause of fatigue in women of child-bearing age,” Favrat said.

“For women with unexplained, prolonged fatigue, iron deficiency should be considered,” he added.

While it was revealed that taking iron supplements will significantly increase energy levels, taking too much iron can also be dangerous.

Rick Miller, a spokesman for the British Dietetic Association, said that using too much iron could cause organ failure. He also stressed that fatigue is multifactorial, exercise, diet and sleep patterns also play a role.