Iron status in Swedish teenage girls: impact of low dietary iron bioavailability

Abstract

Objective Although it is well known that bioavailability of iron in the diet is important, it has not been fully elucidated in practice. We investigated iron intake and iron absorption in the ordinary diet of free-living individuals in relation to iron status and assessed iron requirements. Methods From a total of 1245 adolescent boys and girls included in the Göteborg Adolescence Study of food habits, 28 adolescent girls registered their food intake during 7 d. Iron intake was assessed on the basis of these 7-d dietary records. Iron absorption was calculated using an algorithm including enhancing and inhibiting dietary factors on iron absorption in relation to individual iron status. Results Available iron intake was 11.5 ± 2.8 mg/d (mean ± SD). The proportion of girls with an iron intake below the Nordic nutrition recommendations was 85% ( n = 24). Calculated iron absorption was 1.09 ± 0.59 mg/d (mean ± SD). Only four girls satisfied their estimated individual iron requirement concerning the absorbed amount of iron. Iron depletion (serum ferritin concentration ≤15 μg/L) was present in 10 girls (36%), 2 of whom were also anemic (hemoglobin concentration ≤120 g/L). Conclusion Swedish adolescent girls seemed to have difficulties satisfying their iron requirement in terms of absorbed amount. The data support the view that iron intake and bioavailability of dietary iron is important when evaluating whether iron requirements have been met.