If you’ve been told you need an iron supplement, it can be quite daunting when you reach the pharmacy aisle and discover the many different iron supplements available. For the purposes of this review, given I am based in Australia, we focus on common iron supplements available in Australia and summarise how they differ, key features and benefits, possible side effects and anything else that is important to know. As always, if you need an iron supplement, please speak to your doctor or pharmacist, or other allied health professional for more advice. And never start taking an iron supplement unless you know you are deficient in iron, based on a blood test or due to your specific dietary pattern which may predispose you to a deficiency (as excess iron in the body can actually be quite toxic). For example, we will see below that animal-based sources of iron are more easily absorbed by the body. For those on a plant-based diet, please ensure you consume enough plant rich iron food sources such as leafy green vegetables, eggs, nuts, wholemeal bread and pasta, dried fruit, beans and lentils. As vitamin C can assist with iron absorption (again more on that below, eating foods that are rich in vitamin C (such as citrus fruits, kiwi fruit, red capsicum and leafy green vegetables) can be beneficial also. 

Other tips include:

• eating iron-rich vegetables along with lysine-rich foods (e.g. quinoa, legumes) to improve absorption
• soak, sprout and ferment grains and legumes to help increase iron absorption
• avoid drinking tea of coffee with meals that are rich in iron, as caffeine may reduce iron absorption.  

Speak to your health professional for individual dietary advice. 

About Iron

Iron is an important mineral in the diet, which plays a role in the production of red blood cells and carries oxygen in the blood around the body (to the body tissues and lungs). This provides the body with an excellent source of energy. When someone has iron deficiency, they have depleted iron stores in the body, which can lead to fatigue, tiredness and decreased immunity.  In some cases, iron deficiency can lead to iron-deficiency anaemia, which is one of the most common nutritional disorders in the world. This type of anaemia is most common in menstruating women, pregnant and lactating women, babies, toddlers, teenage girls and female athletes. 

As mentioned above, different types of dietary iron are absorbed differently by the body. Plant-based foods only contain non-haem iron, whereas animal proteins (meat, poultry and seafood) contain both non-haem and haem iron.  Haem iron is more easily absorbed by the body than non-haem iron.

Iron Supplements

For the purposes of this review, we will only cover over the counter iron supplements which can be purchased from a pharmacy. We will not cover iron injections which can be prescribed by your doctor. 

There are various chemical forms of iron found in iron supplements:

• Ferrous sulphate
• Ferrous fumurate 
• Iron poylmaltose

When reviewing supplements, it is important to note that each of these different chemical forms of iron contain different amounts of free (or elemental) iron for your body to absorb. 

In general, all iron supplements are absorbed best on an empty stomach, about 1-2 hours before meals. However, if the supplements cause stomach upset they can be take with or immediately after food, noting that this may reduce absorption levels. 

Liquid iron supplements may stain the teeth, so are best taken using a dropper that is directed to the back of the throat. 

The dose of the supplement and duration of therapy will vary depending on what the goal of treatment is. In Australia, the usual daily dose for the treatment of iron deficiency anaemeia is 100 -200 mg elemental iron daily in divided doses.

Common side effects of iron supplements are constipation, stomach pain, nausea, darkened urine,  headaches and a metallic taste in the mouth. Gastrointestinal side effects are usually the most common concern with these supplements. This can be minimized by:

• Starting at a lower dose and gradually increasing
• Alternate day dosing
• Taking with meals

The most common supplement brands are listed below, with some details for your review below. 

Ferrous sulphate

Common brands: Ferro-Gradumet (Slow release formulation – 105 mg elemental iron per tablet), Ferro-Grad-C (Slow release, combined with 500 mg vitamin C – 105 mg elemental iron per tablet), FGF (Slow release – 80 mg elemental iron per tablet), Ferro-Liquid ( 30 mg elemental iron per 5 mL dose), Fefol (Slow release – 87.4 mg elemental iron per capsule, combined with 300 mcg folic acid per capsule)

Ferrous fumurate

Common brands: Ferro-tab (Immediate release – 65.7 mg elemental iron per tablet), Ferro-f-tab (Immediate release – 100 mg elemental iron per tablet)

Iron poymaltose

Common brands: Maltofer tablets (100 mg elemental iron per tablet), Maltofer syrup (50 mg elemental iron per 5 mg dose)

Natural Iron 

Spa-Tone liquid iron sachets contain 100% natural iron from mineral water (that is very well absorbed by the body) with each 5 mL containing 5 mg of elemental iron. 

Note: use of iron in pregnancy and breastfeeding will be covered in the pregnancy and breastfeeding multivitamin review that will be published in the coming months.

Food Interactions?

When taking iron supplements, it is best to separate the dose from certain foods, which can pair with the iron and reduce its absorption. Try to avoid the following 1 hour before or 2 hours after iron supplements – dairy foods, eggs, spinach, tea or coffee or wholegrain breads.

It is also important to note that you should not take iron supplements and antacids or calcium supplements at the same time. Space doses 1 to 2 hours apart, to get the full benefit from each. 

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