Iron deficiency in adolescent female dancers.

The iron balance of 25 adolescent dancers and 23 control females of the same age were studied. The concentrations of fasting blood haemoglobin, serum iron, serum transferrin and serum ferritin were determined. Iron supplementation (ferrous sulphate corresponding to 100 mg of elemental iron per day) was instigated if body iron stores were low (serum ferritin less than 30 micrograms.l-1). Blood samples were drawn again after ten weeks. Low haemoglobin concentration (blood haemoglobin less than 125 g.l-1) was more prevalent among dancers than among control subjects. Reduced iron stores as well as completely absent iron stores (serum ferritin concentration less than 12 micrograms.l-1) were equally common in both groups (25% of the subjects). Iron supplementation reduced the number of anaemic girls from 16 to 4 and the highly significant difference in haemoglobin level between the treated and untreated groups disappeared. Ten weeks of iron therapy was not, however, long enough to increase iron stores.