Iron absorption is more closely related to iron status than to daily iron intake in 12- to 48-mo-old children

Few studies have evaluated iron absorption in small children after the first year of life. Our objectives were to examine the relations among iron intake, iron absorption, and iron status in a group of healthy children. We studied 28 children, ages 12 to 48 mo, after a 7-d home adaptation to a diet representative of their usual daily mineral intake. A multi-tracer stable isotope study was performed to assess iron absorption both from a meal ( ⁵⁸Fe) and from a reference iron dose (⁵⁷Fe) given with ascorbic acid without a meal. Iron intake was 6.9 ± 2.4 mg, approximately the 35th percentile of typical U.S. intakes. Absorption of ⁵⁸Fe was related to serumferritin (r² = 0.319, P = 0.0018) and more so to reference dose iron absorption (r² = 0.653, P < 0.0001). Iron absorption was negatively correlated with zinc intake (r² = 0.090, P = 0.0049) but was not correlated with iron intake (P = 0.20). However, zinc intake was not correlated with measures of iron status, including reference dose iron absorption and serum ferritin (r² < 0.1, P > 0.25). Total absorbed iron was similar to needs estimated by the Institute of Medicine. We conclude that iron absorption in young children is more closely related to iron status than to iron intake. Reference dose iron absorption may be superior to serum ferritin as a surrogate measure for iron status in this age group. Although zinc intake may affect iron absorption from a meal, it does not appear to have a detectable effect on overall iron status in otherwise well-nourished children.