Lesson 7: Microminerals
7. Microminerals
Also known as trace minerals, iron, zinc, copper, selenium, manganese, iodine, chromium and molybdenum are required by humans in tiny amounts and thus must also be supplied to preterm infants.
Among the microminerals, iron is particularly important for preterm infants. Up to 77% of preterm infants develop iron deficiency (ID) anemia in their first half year of life if they do not receive enough iron from supplements or formula (Domellöf 2014). Adequate iron is also important for cognitive and motor development. Iron deficiency in childhood is associated with lower scores on cognitive and behavioral tests in later life (Domellöf 2014).
Delaying umbilical cord clamping by 30-120 seconds at delivery of a preterm infant can lower the subsequent need for blood transfusions. Additionally, the procedure decreases the risk of intracranial hemorrhage (ICH) and necrotizing enterocolitis (Rabe et al. 2012). The typical VLBW infant loses about 6 mg/kg of iron per week to blood draws. A transfusion provides about 8 mg/kg of iron and erythropoietin treatment increases iron requirements significantly (see Table 4) (Domellöf 2014). These common interventions must be considered when calculating the iron needs of a preterm infant.
Iron intakes are much more often too low than too high in preterm infants. However, iron overload is possible because the body has no way of excreting excess iron. If too much iron is supplied to preterm infants, there may be an increased risk of infections, poor growth, and retinopathy of prematurity (Domellöf 2014).
There is enough scientific evidence to support recommendations for iron supplements. Recommended dosages for supplementation of other microminerals in preterm infants are based largely on expert consensus (Domellöf 2014). Please refer to Table 4 for micronutrients recommended values.
Table 4: Microminerals for preterm infants
ENeA own table. Data from: Domellöf 2014; Koletzko et al. 2014a; Koletzko et al. 2005.
Legend:
ID=iron deficiency; BW=birthweight; ROP=retinopathy of prematurity; CNS=central nervous system; PN= parenteral nutrition
Figure 10. Typical skin rash in an infant with zinc deficiency.
Source: Domellöf 2014, reprinted with kind permission of Nicholas Embleton and S. Karger AG, Switzerland
