Summary: Iron deficient anaemia is treated with iron supplementation. Testing is usually completed as a response to a variety of symptoms.
Who’s it for: Pharmacists & Prescribers
What is iron deficiency anaemia?
Iron deficiency occurs as result of a long-term negative iron balance. There is a spectrum from iron depletion to iron deficiency anaemia.
- Anaemia, in this instance, is diminished red blood cell production due to low iron stores
- The cause is often multi-factorial, and may be broadly attributed to: dietary deficiency, malabsorption, increased loss or increased requirements
In all cases, the underlying cause of the iron deficiency should be determined and treated.
Anaemia Thresholds
(Defined as haemoglobin -2SD below the normal)
Patient Group | Hb Below (g/L) |
Men >15 | 130 |
Non-pregnant Women > 15 | 120 |
Children 12-14 | 120 |
Pregnant Women | 110 (Through Pregnancy)
105 (Adequate in 2nd/3rd Trimesters) |
Postpartum | 100 |
- Serum ferritin level is the biochemical test, which most reliably correlates with relative total body iron stores. In all people, a serum ferritin level of less than 30 micrograms/L confirms the diagnosis of iron deficiency. However:
- Ferritin levels are difficult to interpret if infection or inflammation is present, as levels can be high even in the presence of iron deficiency
- Ferritin levels may be less reliable in pregnancy
Prescribing supplements
After addressing the underlying causes, the aim of treatment is to restore haemoglobin levels and red cell indices to normal, and to replenish iron stores.
- A dose of 65 mg elemental iron (ferrous sulfate 200 mg) once daily (on an empty stomach) is needed to treat iron deficiency anaemia
- Dose-related adverse effects (gastrointestinal disturbance) from taking an iron supplement are commonly experienced
Newly diagnosed anaemia:
- Prescribe iron for 3 months (e.g. ferrous sulfate 200mg OD)
- Recheck haemoglobin levels (FBC) after 4 weeks of iron supplement to assess response. The haemoglobin concentration should rise by about 20 g/L over 3–4 weeks
- if levels are improving continue iron and repeat bloods after 2-4 months to ensure levels have returned to normal
- if levels are not improving - refer to GP
- Once haemoglobin concentration and red cell indices are normal:
- Continue iron treatment for 3 months to aid replenishment of iron stores, then STOP, no need to retest before stopping
- Monitor FBC periodically e.g. 3 monthly for 12 months then 6-monthly for 2-3 years
Ongoing iron supplementation
- An ongoing prophylactic dose of iron (200 mg ferrous sulfate daily) may be beneficial in some people who have:
- Recurring anaemia (such as in an elderly person) and further investigations are not indicated or appropriate
- An iron-poor diet — for example, vegans
- Malabsorption — for example, coeliac disease
- Menorrhagia
- Women who are pregnant
- People undergoing haemodialysis