Serum ferritin in children and adolescents. Results from population surveys in 1979 and 1986 comprising 1312 individuals.

Iron stores were assessed by measurement of serum ferritin in a population survey comprising 436 randomly selected urban Danish schoolchildren (219 boys, 217 girls) 7 to 17 years old. Median ferritin values were similar in boys and girls 7 to 13 years old, while 14- to 17-year-old boys had significantly higher values than girls of similar age (p < 0.0001). Boys had stable median ferritin values from 7 to 15 years of age, after which a significant rise was found from 16 to 17 years of age (p < 0.01). Girls had unchanged median ferritin values from 7 to 11 years of age, after which a significant decrease was found from 12 to 17 years of age (p < 0.01). The frequencies of low ferritin values < 16 micrograms/l (indicating absent iron stores) were: Children 7 to 11 years, 1.0%. Boys 12 to 15 years, 4.5%; 16 to 17 years, 0%. Girls 12 to 15 years, 7.6%; 16 to 17 years, 16.7%. Ferritin levels in the reported 1986 survey were significantly higher than those obtained in a similar survey in the same area in 1979. The results indicate an overall increase in iron stores in Danish schoolchildren and adolescents during 1979-1986, possibly due to an increase in the consumption of meat, and in the use of vitamin-mineral supplements containing iron.