Blood selenium content and glutathione peroxidase activity in children with cystic fibrosis, coeliac disease, asthma, and epilepsy.

Long-term selenium status in children from the North-East of Scotland was estimated using whole blood selenium content (BSe) and glutathione peroxidase activity (BGSH-Px). BSe was significantly lower than the reference range in children with cystic fibrosis, coeliac disease and in older patients with phenylketonuria. Whereas BGSH-Px of all the children with coeliac disease and those with cystic fibrosis aged over 6 years matched the reference range, it was reduced in younger patients with cystic fibrosis and in children with dietetically treated phenylketonuria. No child had clinical features of selenium deficiency. BSe in treated epileptics and asthmatics conformed to the reference range, but BGSH-Px in both groups was increased significantly; this was most evident in those receiving corticosteroid preparations.