Your guide to iron supplements

Do you feel like you’re lacking in energy? Always tired? Struggling to concentrate and focus? Difficulty exercising?

A common nutritional deficiency, it's these symptoms of low iron that can often get ignored. Let’s take a look at the importance of iron, deficiency signs, and guidance around iron supplementation.

What is iron and what does it do? 

Iron is a mineral that the body needs for physical growth and development, neurological development, and the synthesis of hormones. Your body needs it to make hemoglobin and myoglobin, proteins in the red blood cells that carry oxygen from the lungs to all parts of the body, and in skeletal muscle. 

When it comes to dietary iron, there are two main types; haem and non-haem.

The haem form comes from animal products and is more easily absorbed by the body. These iron rich foods are predominantly red meat, as well as seafood and poultry. 

Comparatively, non-haem from eggs and plant-based sources such as fortified grains, dark leafy greens, cacao, hemp seeds, sundried tomatoes, and cashews is less bioavailable.

Studies have shown that diets excluding meat and seafood, such as vegetarian and vegan diets, have a higher risk of deficiency because the absorption rate of these vegetarian sources of iron is considerably less. 

Enhancing the absorption of non haem iron is, therefore, particularly important. Vitamin C helps the body absorb iron and eating a wide variety of foods such as citrus fruits, kiwi fruit, berries, broccoli, capsicum, and tomato alongside plant-based sources of iron is favourable. 

Caffeine can interfere with the absorption of iron, so it is important to separate any caffeine consumption to ensure optimal absorption. The health of your gut will also determine how well you absorb nutrients, including iron.

Citrus fruits, kiwi fruit, berries, broccoli, capsicum, and tomato are a good source of vitamin C which helps the absorption of non-haem iron.

How much do I need? 

Iron requirements vary from male to female and various life stages.

For males over the age of nine and females over the age of 51, the recommended daily intake is 8mg.

For girls between 14 and 18 years old it's 15mg. This increases to 18mg/day for females during reproductive years (19-50) and again during pregnancy to 27mg/day.

For all babies, under 3 years old the recommended daily intake is 9mg, which increases to 10mg between four and eight years of age. 

Am I getting enough?

A lack of iron is defined as a reduction in the total content of iron in the body, while, iron deficiency anemia is when iron deficiency is so severe that there isn't enough to produce red blood cells.

Signs and symptoms of iron deficiency and anemia include general weakness, tiredness, irritability, poor concentration, headache, and intolerance to exercise.

Because our immune cells require iron for synthesis and functionality, if your levels are low this may impact your immune health. 

Iron is a particularly important mineral for pregnant women, with the fetus and placenta increasing the need for red cell production. Because of this, the amount that women need increases during pregnancy.

Do you need a supplement?

It can be overwhelming when choosing the right supplement, particularly when supplementation can cause unwanted gastrointestinal side effects of discomfort, nausea and constipation.

Unlike other minerals, iron levels in the body are controlled only by absorption, so excessive iron at once, such as a high dose supplement may heighten the chance and severity of these side effects. 

Bis-glycine iron (II) and ferrous sulfate are the most common forms found in supplements. The amount of Iron bis-glycinate is generally around 120mg (equivalent elemental iron of 24mg) per tablet, while ferrous sulfate can be three to five times this amount per tablet.

Due to its form and dose, iron bis-glycinate is more gentle on the stomach and generally better tolerated than ferrous sulfate. 

A hormone synthesized in the liver, hepcidin, regulates the body’s iron absorption. When hepcidin levels are low, this allows for more to be absorbed. When iron levels increase hepcidin starts to slow the rate of iron absorption.

Studies suggest that iron-induced increases in hepcidin influence its absorption and that supplementing with higher doses more frequently may inhibit absorption. Because of this, evidence also suggests that alternate-day supplementation may be an optimal regime in maximizing absorption while minimizing adverse side effects such as gastrointestinal irritation and discomfort.

It is important to note, this supplementation regime may not be beneficial for people with severe anemia or during pregnancy so it is always best to consult with your health professional.

Other considerations 

Hemochromatosis is a common genetic condition that causes the body to absorb too much iron leading to an iron overload. Symptoms of hemochromatosis may be similar to iron deficiency, which is why it is vital that detection and diagnosis of iron deficiency should always be performed using a blood test. 

Mineral supplements should not replace a balanced diet. They can only be of assistance if the dietary intake is inadequate, or in times when requirements are increased, such as pregnancy. If you believe you may be iron deficient, always consult your health professional first. 

Reviewed by the healthylife Advisory Board November 2021.