Iron requirements in infancy and childhood.

A critical characteristic of iron nutrition in infancy, as compared to adults, is the greater dependency of the infant on external sources of iron for daily red cell production. Dallman et al. (1) have calculated that in a 1-year-old, 10-kg infant, dietary iron must provide 30% of the needs for hemoglobin iron turnover as compared to only 5% in the adult male (Table 1). This imposes disproportionate requirements of iron to the infant. In addition, infants may (a) consume diets with a low iron content or poor iron availability; (b) be born with decreased iron reserves, as is the case with premature infants; (c) grow too rapidly and have excessive demands; or (d) have increased iron losses. The sum of these factors explains the high occurrence of iron deficiency observed at this age. The main factors determining iron requirements in infants and children are the iron endowment at birth, the requirements for growth, and the need to replace losses.