Compare iron supplements

Iron contributes to normal formation of red blood cells and haemoglobin, normal oxygen transport in the body, normal energy-yielding metabolism, normal function of the immune system and the reduction of tiredness and fatigue. Because of menstruation, women of childbearing age have a considerably higher requirement than men, as do pregnant women.

Good sources of iron are meat, pulses, wholegrains, oats, nuts and green leafy vegetables. Iron from plant foods is less well absorbed; vitamin C from fruit and vegetables in the same meal improves absorption, while coffee and black tea inhibit it.

Unlike many vitamins, the body can hardly excrete excess iron. A long-term excessive intake can put a strain on organs. The BfR therefore advises taking iron supplements only when a need has been established by a doctor. Tiredness can have many causes – a blood count including a ferritin value provides clarity.

Iron supplements are dangerous for children if they accidentally swallow larger amounts. So be sure to store them out of children's reach.

Iron can cause gastrointestinal complaints such as nausea or constipation and darken the stools. Iron bisglycinate is considered comparatively well tolerated. Iron is best absorbed on an empty stomach; if you don't tolerate that, take it with a small meal without dairy products. Iron and certain medicines, such as thyroid hormones or some antibiotics, affect each other – leave a time gap and discuss taking it with your doctor or pharmacist.

Food supplements are no substitute for a balanced, varied diet or a healthy lifestyle. If you have a pre-existing condition, are pregnant or breastfeeding, or take medication regularly, ask a doctor or pharmacist for advice before taking them. Do not exceed the recommended daily intake stated on the pack. The information on this page is for general guidance only and is no substitute for individual advice.