Indications for and administration of oral iron supplementation

In most patients with iron deficiency, it is reasonable and appropriate to trial oral iron supplementation. However, patients who do not tolerate or cannot absorb oral iron supplements (eg following gastrectomy) require intravenous iron supplementationKo, 2020.

Many of the iron-containing supplements available from health food stores and pharmacies do not have adequate elemental iron to be an effective treatment for iron deficiency. It is important to ensure that the patient is taking a sufficient dose of elemental iron; Examples of oral iron preparations and their elemental iron content lists iron preparations that contain adequate elemental iron. Vitamin C is often given concurrently to optimise iron absorptionKo, 2020.

For oral iron supplementation, use:

An iron overdose can be fatal for a child; see Iron poisoning for detailed information.

Table 1. Examples of oral iron preparations and their elemental iron content

Brand name

and dose form

Elemental iron content

Iron salt and content

Other active ingredients

Ferro-tab

film-coated tablet

65.7 mg

ferrous fumarate 200 mg

nil

Ferro-grad F, Ferrogen Iron + Folic Acid

modified-release tablet

80 mg

ferrous sulfate 250 mg

folic acid 300 micrograms

Fefol

capsule containing delayed-release pellets

87.4 mg

ferrous sulfate 270 mg

folic acid 300 micrograms

Ferro-F

film-coated tablet

100 mg

ferrous fumarate 310 mg

folic acid 350 micrograms

Maltofer

film-coated tablet

100 mg

iron polymaltose 370 mg

nil

Ferro-grad, Ferrogen, Ferrovance

modified-release tablet

105 mg

ferrous sulfate 325 mg

nil

Ferro-grad C, Ferro-Max C, Ferrogen Iron + Vitamin C, Ferrovance C

modified-release tablet

105 mg

ferrous sulfate 325 mg

ascorbic acid (vitamin C) 500 mg

Ferro-liquid

oral liquid

6 mg/mL

(90 mg/15 mL)

ferrous sulfate heptahydrate 30 mg/mL

(450 mg/15 mL)

nil

Maltofer

syrup

10 mg/mL

(100 mg/10 mL)

iron polymaltose 37 mg/mL

(370 mg/10 mL)

nil

Adverse effects such as nausea, bloating, constipation and diarrhoea are common with oral iron supplementation, particularly during pregnancy. To reduce these adverse effects, the daily dose can be administered in divided doses or every second dayStoffel, 2017Ko, 2020.

Oral absorption of iron is reduced by food, so iron supplements should be taken at least 1 hour before eating; however, if this worsens gastrointestinal adverse effects, iron can be taken with foodKo, 2020. Oral absorption is also reduced by calcium supplements, proton pump inhibitors, H2-receptor antagonists, antacids and tea. Warn patients that oral iron supplements cause black stools.

Check patient adherence because poor adherence is a frequent cause of an inadequate responseKo, 2020.