Iron Deficiency in Childhood: Causes and Consequences for Child Development

Abstract

The main causes of iron deficiency (ID) are briefly discussed, followed by the examination of studies of ID and child cognitive and motor development and behaviour for evidence of a causal link, classifying them by study design. Iron deficiency anaemia (IDA) is associated with many psychosocial and economic disadvantages that can affect child development and could explain the frequently demonstrated relationship between IDA and poor development and behavioural differences. There is evidence of changes to brain function in infants with IDA. Many treatment trials lack statistical power due to small samples, including children without ID in the sampling or iron treatment resulting in little or no differences in iron status between placebo and treated groups. In children with IDA under 3 years, randomized trials indicate that iron supplementation is usually beneficial to motor development, but the effect on mental development is inconsistent. Iron supplementation also has a beneficial effect on cognitive function in school-aged children with IDA. Evidence for a threshold level of ID at which child development is affected is inconsistent, but children with IDA are most likely to benefit from iron supplementation. Possible harmful effects of iron supplementation in iron-replete children on growth and morbidity have to be considered when developing programmes and policy.

Iron Supplementation in Pregnancy or Infancy and Motor Development: A Randomized Controlled Trial

“…Our findings of better motor outcome with iron supplementation in infancy are in agreement with a 2010 expert review of previous RCTs. 13 However, the results did not confirm our prediction of greater benefits with iron supplementation during both pregnancy and infancy. The lack of benefit of iron supplementation during pregnancy on motor development is consistent with the sole relevant RCT in a recent summary.…”

“…[9][10][11][12] Establishing a causal connection between lack of iron and lower developmental test scores in humans largely depends on randomized controlled trials (RCTs) of iron supplementation. In a 2010 expert review that organized RCTs of iron supplementation in infancy according to duration and child age, 13 6 of 8 pertinent RCTs reported benefits on motor development. The investigators considered the evidence sufficient to conclude that long-term (>2 months) iron supplementation during infancy improves motor development.…”

Prévention de la carence en fer chez le nourrisson, l’enfant et l’adolescent

“…Par ailleurs, en pé-riode de menstruation, les adolescentes présentent un risque encore plus élevé avec des besoins en fer plus importants pour couvrir les pertes menstruelles [3] . D'autres facteurs de risque et les conséquences néfastes de la CF et de l'AF sur la santé pendant l'enfance sont décrits dans un autre article de ce présent numéro [6] .…”

Prevention of Iron Deficiency in Infancy, Childhood and Adolescence

“…Menstruating adolescent girls are at further risk as they need additional iron to cover menstrual iron losses [3] . Additional risk factors and negative health consequences of ID and IDA throughout childhood are described in another article in this issue [6] .…”