A longitudinal study of serum ferritin in 319 adolescent Danish boys and girls examined in 1986 and 1992

This study examined trends in iron status in adolescents. Serum ferritin was measured in 1986 and 1992 in 319 Danes (161 males) stratified into 5 groups: I. median age 9 yr in 1986 vs. 15 yr in 1992; II. 11 vs. 17 yr; III. 13 vs. 19 yr; IV. 15 vs. 21 yr; V. 17 vs. 23 yr. Males in group I demonstrated no change in ferritin or estimated iron stores in mg/kg; groups II-V displayed an increase in iron status parameters. All groups showed an increase in estimated total iron stores. Changes in iron status parameters were inversely correlated with height velocity in group III, and positively correlated with height velocity in group V. Females in age groups I and II demonstrated a fall in ferritin and estimated iron stores in mg/kg in association with menarche; values were unchanged in groups III and IV, and increased in group V. All groups showed an increase in estimated total iron stores. Changes in iron status parameters were inversely correlated with height velocity in groups I and II. In conclusion, ferritin levels in adolescents display great variation during growth spurt and at menarche. Changes in ferritin showed no consistent association with growth velocity. In both genders, estimated total iron stores increased with age.