Matern Child Health J. 2019 Sep;23(9):1240-1250. doi: 10.1007/s10995-019-02764-x.

Effect of Infant Iron Deficiency on Children’s Verbal Abilities: The Roles of Child Affect and Parent Unresponsiveness

East P¹, Delker E², Blanco E², Encina P³, Lozoff B⁴, Gahagan S².

^{1 Department of Pediatrics, University of California, San Diego, 9500 Gilman Drive, Mail Code 0927, La Jolla, CA, 92093-0927, USA. peast@ucsd.edu.}

^{2 Department of Pediatrics, University of California, San Diego, 9500 Gilman Drive, Mail Code 0927, La Jolla, CA, 92093-0927, USA.}

^{3 Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile.}

^{4 Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA.}

ABSTRACT

BACKGROUND: Infants who are iron-deficient anemic seek and receive less stimulation from their caregivers, predisposing such children to be functionally isolated.

OBJECTIVES: To test the sequence whereby iron deficiency in infancy contributes to children’s disengagement from the environment, which reduces parent stimulation which, in turn, contributes to children’s poor verbal skills.

METHODS: Chilean children (N = 875, 54% male) were studied, 45% of whom were iron deficient or iron-deficient anemic in infancy. We used structural equation modeling to test the sequence outlined above and to examine the effect of infant iron status on children’s verbal performance at ages 5 and 10 years including the roles of child and parent intermediate variables.

RESULTS: Severity of iron deficiency in infancy was associated with higher levels of children’s dull affect and social reticence at 5 years (β = .10, B = .26, SE = .12, p < .05), and these behaviors were associated with parent unresponsiveness (β = .29, B = .13, SE = .03, p < .001), which related to children’s lower verbal abilities at age 5 (β = - .29, B = - 2.33, SE = .47, p < .001) and age 10 (β = - .22, B = - 3.04, SE = .75, p < .001). An alternate model where poor iron status related directly to children’s verbal ability was tested but not supported.

CONCLUSIONS: Findings support functional isolation processes resulting from a nutritional deficiency, with iron-deficient anemic infants showing affective and behavioral tendencies that limit developmentally stimulating caregiving which, in turn, hinder children’s verbal abilities.

KEYWORDS: Child affect; Iron-deficiency anemia; Parent stimulation; Social reticence; Verbal abilities