Experts push for higher ferritin threshold to catch iron deficiency

Iron deficiency may be going undetected because current ferritin thresholds are too low, experts say, as Yle reports on calls to identify the common and treatable condition earlier.

The American Society of Hematology recommends that adults be considered iron deficient when their ferritin level is 30 micrograms per litre or lower. The recommendation also applies to people who menstruate or are pregnant. For people with heavy menstrual bleeding and those with anaemia during pregnancy, the society recommends a threshold of 50 micrograms per litre.

Low ferritin indicates that the body’s iron stores are depleted. Iron deficiency can lead to anaemia because iron is needed to produce haemoglobin in red blood cells, but deficiency can also occur without anaemia. Inconsistent reference ranges and testing practices have made the condition harder to identify, the society says.

Finnish doctors favour higher cutoffs

In Finland, the lower end of laboratory reference ranges for ferritin is generally around 13 to 15 micrograms per litre for women and 20 to 30 for men, depending on the laboratory.

Tuija Männistö, a professor of clinical chemistry at the University of Eastern Finland and chief physician in clinical chemistry at ISLAB, cautiously supports adopting the American recommendations in Finland. She says research supports using a level of 30 as an indicator of iron deficiency in adults, but says the implications for Finland’s healthcare system would need to be discussed, including what further tests patients would need.

Gabriele Sved, a neurologist at Terveystalo, would set the threshold as high as 50 for adults, people who menstruate and those who are pregnant. She says it should be higher still for groups at increased risk of iron deficiency.

Männistö says Finnish laboratories generally treat a ferritin level of 20 as an indication of iron deficiency and that there may be room to raise the cutoff. Guidance published in Patient’s Medical Journal says iron deficiency should be suspected when ferritin falls below 15 to 30 micrograms per litre, the person has symptoms and they belong to a risk group, such as people with heavy periods.

Terveyskirjasto, a Finnish health information service, says a ferritin level of 30 has been considered an indicator of iron deficiency in adults. Sved says she has repeatedly seen people seeking help for fatigue told that their results are normal because their ferritin is 20. Raising the lower reference limit could help them get treatment, she says.

A common and treatable condition

The American Society of Hematology describes iron deficiency as a widespread condition that particularly affects women. Patient’s Medical Journal estimates that as many as 20 per cent of women worldwide have iron deficiency.

According to Terveyskirjasto, the most common cause is blood loss, including through menstruation. Pregnancy, coeliac disease and other conditions that affect nutrient absorption, as well as a limited diet, can also lead to iron deficiency.

Iron deficiency and iron-deficiency anaemia can be treated with iron supplements. If medication is insufficient or unsuitable, iron can be given intravenously.