According to Dr Jonathan Baird-Gunning and Dr Jonathan Bromley of Canberra Hospital, writing in the latest edition of Australian Prescriber. State other at-risk groups include the very young and the very old, and people with restrictive dietary patterns such as vegetarians and vegans.
They point out that detecting iron deficiency remains a challenge, even when assessing serum ferritin, which is is the most sensitive and specific test for evaluating a patient’s iron stores
“Diagnosing iron deficiency can be challenging as ferritin is also an acute-phase protein, which can be elevated in the presence of infections, autoimmunity, chronic kidney disease and certain malignancies. In these scenarios ferritin can potentially overestimate the patient’s iron stores.
“Serum ferritin up to 300 microgram/L can still be compatible with iron deficiency in the presence of inflammation and needs to be interpreted with other parameters measured in the iron profile and supportive red-cell indices such as mean corpuscular volume and a blood film.”
Signs of untreated iron deficiency can include fatigue, the worsening of some symptoms like angina, disorders like restless leg syndrome, and memory and mental processing problems in children.
In addition to dietary changes, the authors state that oral iron therapy via supplementation should correct anaemia and replenish iron stores.
“Therapeutic Guidelines suggests ferrous sulfate at a dose of 325–650 mg daily (equivalent to 105–210 mg elemental iron), however other guidelines recommend higher doses.10 There are no comparative trials evaluating effectiveness or tolerability. Ferrous fumarate and gluconate salts are equally effective in practice. Vitamin C enhances iron absorption and is compounded with several iron preparations,” they state.
However, they add patients should be advised to take oral iron supplementation on an empty stomach as phosphates, phytates and tannates in food bind iron and impair absorption.
They also warn that while there are obvious advantages to oral iron supplements such as cost, safety and ease of access, there are also several limitations.
“Adverse effects such as constipation, dysgeusia and nausea reduce adherence,12 and hence effectiveness, particularly when the recommended duration of therapy is 3–6 months. Poor adherence is a common cause for failure to respond to oral iron therapy, however other causes should also be considered. Liquid iron replacement can be trialled in patients intolerant of iron tablets. It can be taken in divided daily doses reducing gastrointestinal adverse effects, however it can discolour teeth,” they add.