Haemoglobin levels in Cardiff children of nursery school age.

A study of 1074 apparently healthy children aged 2 to 5 years revealed a wide range of haemoglobin, extending from 6·8 g/100 ml to 15·6 g/100 ml. The mean Hb was 12·3 g/100 ml, with only minor variations for age, sex, and season. A significant increase in the Hb followed iron administration if the initial Hb was less than 10·5 g/100 ml, but there was no rise in the mean value if the initial level exceeded 12·5 g/100 ml. Taking 10·5 g/100 ml as the level below which anaemia is deemed to exist, 5·2% of the total study population were anaemic, compared with 0·3% in private nurseries, 3·7% in local authority nurseries, and 15% of infants on admission into the care of residential nurseries.