Source: Nutrition  |  Posted 9 years ago

The current definitions for iron deficiency and iron deficiency anaemia in infants are inadequate and need evaluation.

A study of 263 exclusively breast-fed infants in Honduras and Sweden who were randomly assigned to receive iron supplementation or placebo has led researchers in Sweden and the United States to this conclusion.

Blood samples were taken from the children at age 4, 6 and 9 months. Reference ranges were determined using three different approaches for defining iron-replete infants. The researchers evaluated various variables for predicting the haemoglobin response to iron.

Dr M Domellof, from the Department of Clinical Sciences, Pediatrics, Umea University, Umea, Sweden, said, "The haemoglobin response to iron was not a useful definition of iron deficiency anaemia at 4 months of age. Haemoglobin, mean cell volume, and zinc protoporphyrin at 6 months as well as growth variables predicted the haemoglobin response at 6-9 months, but ferritin and soluble transferrin receptors at 6 months did not."

The investigators concluded that there was a need for a re-evaluation of the definitions of iron deficiency and iron deficiency anaemia.

They had set out to establish the cut-off values for the different variables. They found the two standard deviation cut-off values in iron-replete infants to be as follows: haemoglobin <105 g/L at 4-6 months and <100 g/L at 9 months; zinc protoporphyrin >75 micro mol/mol haem at 4.6 months and >90 micro mol/mol haem at 9 months; ferritin <20 micro g/L at 4 mo, <9 micro g/L at 6 mo and <5 micro g/L at 9 mo; and soluble transferrin receptors >11 mg/L at 4-9 months.