Iron deficiency is defined as a state where iron concentrations are insufficient to maintain the body's normal physiological functions. It often results from inadequate iron intake during phases of high iron demand like growth phases (pregnancy/ gestation) or blood loss and can be measured through several clinical indicators listed in the table 575-0.3-01 (Baker & Greer, 2010). In severe cases, patients with iron deficiency can develop iron deficiency anaemia. Iron deficiency anaemia is characterised by a decrease in red blood cells to such an extent that the capacity of blood to transport oxygen is impaired. The change can be measured by evaluating the haemoglobin concentration and can also be accompanied by a change in the shape or size of red blood cells (WHO, 2016).
Iron deficiency is considered the most common micronutrient deficiency worldwide, affecting about 5 ‑ 10% of European children aged 1 ‑ 3 years. About 25% of preschool children worldwide actually suffer from iron deficiency anaemia (Domellöf et al., 2014).
Young children in particular are at risk of developing a nutrient deficiency due to their rapid growth. Further risk factors include low-birth weight (LBW), high intake of cow's milk and low intake of iron-rich complementary foods, but also low socioeconomic and immigrant status. The iron stores of healthy term infants are usually high enough at birth to permit doubling of birth weight before being depleted. Thereafter, at the age of around 4 ‑ 6 months, an external iron supply through iron-rich complementary food or supplementation becomes necessary to prevent deficiencies. The consequences of iron deficiency in early life stages are severe and include poor neurodevelopment, growth retardation and impaired immune response (Lonnerdal et al., 2015, Domellöf et al., 2014, Agostoni et al., 2008, Fewtrell et al., 2017).
Pregnancy represents a period of increased iron requirements due to maternal changes and the foetoplacental development. Iron demands amount to around 1000 mg in total during pregnancy, women often enter this phase with insufficient iron stores to meet these demands (Fisher & Nemeth, 2017). This increases the risk of iron deficiency and iron deficiency anaemia, which can severly affect maternal and infant health by increasing the risk of premature birth, low birth weight, impairment of the infants neurological development and maternal mortality. Pregnant women with iron deficiency anaemia often show reduced physical and mental performance, such as cardiovascular strain and an increased risk of complications. The WHO therefore recommends iron supplementation for all pregnant women with 100 mg of iron/day in non-aenemic women during the second half of pregnancy (Fisher & Nemeth, 2017, WHO/ FAO, 2004).
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