Is iron deficiency more widespread than we think?

Having enough iron in the blood, we know, is important. But when should the doctor consider supplements when faced with a tired, depressed or anxious patient? Ontario has just established a new limit for iron, higher than the thresholds set in Quebec and elsewhere in Canada. Explanations.



30 micrograms

In early September, Ontario doctors received a notice from Ontario Health informing them of a change. Now the lower limit for ferritin (the main iron storage protein) in adults increases to 30 micrograms per liter of blood. What does that change, concretely? In blood tests, results below 30 will be flagged as abnormal, prompting doctors to inquire about their patients’ symptoms and – if appropriate – prescribe iron supplements. The pool of Ontarians likely to receive ferritin results considered “low” is growing significantly.

More women

To understand this new limit which separates “normal” results from “low” results, let’s look at the thresholds that were considered in Ontario before September 9 (and which are still those of other Canadian provinces). These minimum thresholds are heterogeneous: they vary from one laboratory to another and from one population to another, but for Canadian women, we are talking about a lower limit of approximately ten to fifteen micrograms of ferritin. These are “reference values”, based on values ​​obtained in healthy populations. According to researchers, these thresholds do not reflect the reality of iron deficiency. Especially among women.

Equity

“We are really happy with this change: we have been working on it for four and a half years! », rejoices the DD Michelle Sholzberg, hematologist, director of hematology at the University of Toronto and researcher at St. Michael’s Hospital. Opinion leader in this movement for change, the DD Sholzberg is concerned about women’s health and equity in hematology, the medical specialty concerned with the elements that make up blood. “Iron deficiency with anemia and iron deficiency without anemia are more common in women of reproductive age,” emphasizes the DD Sholzberg. For what ? Because women are unable to compensate, in their diet, for the loss of iron caused by their periods.

PHOTO PROVIDED BY MICHELLE SHOLZBERG

The DD Michelle Sholzberg, hematologist, director of hematology at the University of Toronto and researcher at St. Michael’s Hospital

Related issues

“Just because it’s really common doesn’t mean it’s normal!” », estimates the DD Sholzberg. Iron deficiency is associated with several consequences, such as fatigue, depressive or anxiety symptoms, restless legs syndrome, difficulties with attention, etc. “When iron deficiency is severe enough, people develop anemia,” she emphasizes. Does this mean that all blood tests below 30 will result in an iron prescription? No: it will be on a case by case basis. “The change at least gives doctors the opportunity to have a conversation with these patients, particularly about menstrual bleeding and gastrointestinal symptoms,” explains the DD Sholzberg. Doctors may also, depending on the symptoms, consider the option of iron supplements. »

Evidence

Are there any studies showing that a woman with a ferritin of 25, for example, will be less tired or less depressed if she takes iron? The scientific literature on this subject is unclear. Last summer, an American task force (the US Preventive Services Task Force) also concluded that there was “insufficient evidence” for testing and treating the iron levels of pregnant women without deficiency symptoms. The DD Sholzberg agrees: yes, there are significant gaps in the literature, and this reality is not unrelated, according to her, to structural sexism in medicine. “But there are a huge number of scientists and doctors who, like me, are convinced that there is enough evidence, considering the risks associated with iron deficiency,” she says. Michelle Sholzberg hopes that the Ontario example will have an influence elsewhere in Canada and globally.

And in Quebec?

President of the Association of Hematologists and Oncologists of Quebec, Dr.r Normand Blais finds the current movement interesting and he is open to hearing the arguments of his peers. “I completely agree with what they say: low ferritin, without anemia, perhaps merits treatment in certain people,” says Dr.r Blais, who also sees the benefit of raising awareness among health professionals about this. But, according to him, we should not “medicalize a ferritin value” and treat any ferritin below 30, even without symptoms. “The more we raise the ferritin value, the more we medicalize women,” he recalls. Iron supplements can cause side effects, such as heartburn and constipation.

Caution at the Quebec Ministry of Health

Will Quebec follow suit? At the Ministry of Health and Social Services of Quebec (MSSS), it is indicated that “this question does not fall directly under the MSSS, since it is up to each cluster of laboratories to define their reference values”. The MSSS also recalls the recent conclusions of the American working group on the lack of conclusive data in pregnant women.In 2015, a similar result was observed for ages 6 to 24 months. No systematic screening (measurement of serum ferritin in healthy people without symptoms) is therefore recommended,” indicates the communications team.

Learn more

  • 38%
    In Ontario, 38% of women aged 15 to 54 who are not pregnant have an iron deficiency (less than 30 µg/L).

    Source: Xin Wen et al.2022


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