Introduction

Iron deficiency is one of the most common nutritional deficiencies worldwide with potentially dangerous consequences. In Western European countries and the USA, it is found in 3-5% of children, while in developing countries it is found in almost 75% of ^children1. It has been suggested that iron deficiency can impair a child's motor and intellectual development, and these impairments may be irreversible. This article summarises the current positions of the Nutrition Committee of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHTN N⁾², the Nutrition Committee of the American Academy of ^Pediatrics3 and the Centers for Disease Control and ^Prevention1 on the role of iron in infant nutrition, with a particular focus on recommendations for GPs on how to prevent iron deficiency.

Iron

Iron is an essential element for the proper functioning of the body, present in almost all cells, including, among others, the two most important ferroproteins - haemoglobin, involved in oxygen transport, and myoglobin, found in muscles and playing a role in oxygen storage. Other ferroproteins, such as cytochromes, catalases and peroxidases, play a role in cellular metabolism^.2

Iron requirement

Although iron is an essential element for life, its exact requirement is not known^.2 Research findings suggest that healthy, term-born, normal-weight infants have iron stores that cover their requirements for the first six months of life^{.4 5} During this period, the need for exogenous iron, if any, is minimal. In the second half of the first year of life, iron requirements increase rapidly and are estimated to be around 1 mg/kg/d^.3 Compared to infants born at term, with normal or high birth weight, preterm or low-for-gestational-age inf ants are born with lower iron stores, which are depleted around 2-3 months of age. It is estimated that the daily iron requirement of a newborn born prematurely is approximately 4 mg/kg/d^{.6 7}

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Iron absorption

The absorption of iron supplied with food takes place mainly in the duodenum and upper part of the jejunum. The divalent form of iron is best absorbed. Two transport mechanisms coupled to an enzyme that alters the oxidation state of iron are involved in the transport of iron across the intestinal mucosa. To date, only one of these, Divalent Metal Transporter I (DMTI^{)8 9} located in the apical membrane of the enterocyte, has been identified; however, no transporter has been identified in the basolateral membrane. Inside the enterocyte, iron is stored as ferritin. Iron absorption depends on the amount of iron in the body, the rate of red blood cell production, the amount and type of iron in the diet, and the consumption of substances that enhance or inhibit iron absorption^{.2 1}