Glossary Detail

Detailview for term

name of the term: Iron

Short introduction

  • Iron is a trace-element with the symbol Fe. Minerals are divided into 2 groups: (macro) minerals and trace-elements. Different from minerals, trace-elements are only required in very small amounts.
  • Most of the body’s iron is found in red blood cells (in haemoglobin). It gives blood its red colour.

Main natural sources

  • Food contains 2 types of iron: haem and non-haem iron. Haem iron is a part of haemoglobin and myoglobin so found only in animal tissue.
  • Meat, poultry and fish contain 40 percent haem iron and 60 percent non-haem iron.
  • Non-haem iron is found primarily in plant sources: dried beans, peas, lentils, vegetables (spinach) and (fortified) grain products. In animal sources as egg yolk and dairy products.
  • The body better absorbs haem iron than non-haem iron.
  • Enhancers and inhibitors present in the same meal influence absorption of non-haem iron. Enhancers: e.g. vitamin C and red meat, poultry and seafood. Inhibitors e.g.: phytic acid/phytate (legumes, grains, rice), egg protein, soy protein, coffee and tea. Particular minerals, e.g. calcium and magnesium can inhibit the absorption of both haem and non-haem iron. However, the effects of enhancers and inhibitors of iron absorption are reduced by a typical mixed western diet, having little effect on most people’s iron status.
  • Breast milk is low in iron, yet, it is well absorbed and after birth iron stores are sufficient for the first 4 to 6 months of life.

Main function

  • Essential component of hundreds of proteins and enzymes.
  • Component of haemoglobin, a protein that transfers oxygen from the lungs to the tissues.
  • Component of myoglobin, a protein that provides oxygen to the muscles.
  • Found in proteins involved in brain development and function. Involved in e.g. synthesis of myelin (proper conduction of nerve impulses) and neurotransmitters (brain chemicals that communicate information throughout brain and body).
  • Needed for e.g.: growth and development, normal cell functioning and synthesis of some hormones.

Deficiency disease

  • The terms iron deficiency (ID), iron deficiency anaemia (IDA) and anaemia are often used interchangeably. It ranges from depleted iron stores (without health impairment) to iron deficiency with anaemia (inadequate iron to support red blood cell formation affecting the functioning of several organ systems). When iron reserves in the body are depleted, anaemia develops.
  • It is considered a nutritional deficiency of public health significance: all over the world and with serious consequences.
  • It can result from loss of blood in adults (including bleeding from menstrual periods) and from an inadequate diet (infants, children, adolescent girls and pregnant women).
  • It develops gradually. In the beginning there may be no symptoms or signs may be mild. Symptoms e.g.: paleness, weakness, headache, low body temperature, irritability and fatigue. It can affect growth and may lead to long-term, altered behavioural and neural development. Studies in infants suggest that some of these effects may be irreversible.

Recommended daily intake

Latest Dietary Reference Intakes  (DRIs) 
Institute of Medicine (IOM)

Age categoraPer day

Pregnancy27 mg (RDA)
Lactation
14 – 18 years
19 – 50 years
10 mg (RDA)
9 mg (RDA)
Infants 6 – 12 months11 mg (RDA)
Children
 1 – 3 years
 4 – 8 years
7 mg (RDA)
10 mg (RDA)
Males
 9 – 13 years
14 – 18 years
19 – 30 years
31 – 50 years
50 – 70 years
> 70 years
8 mg (RDA)
11 mg (RDA)
8 mg (RDA)
8 mg (RDA)
8 mg (RDA)
8 mg (RDA)
Females
 9 – 13 years
14 – 18 years
19 – 30 years
31 – 50 years
50 – 70 years
> 70 years
8 mg (RDA)
15 mg (RDA)
18 mg (RDA)
18 mg (RDA)
8 mg (RDA)
8 mg (RDA)

 

RDA = Recommended Dietary Allowance.

Synonyms: Iron

Back to list