Randomized double-blind controlled trial on the effects on iron status in the first year between a no added iron and...

Recent research has not only questioned the necessity of iron supplementation in human milk substitutes prior to weaning, but also suggested some potential adverse effects. This study investigated the hypothesis that infant formula need not contain added iron in the first 3 mo. Healthy term infants were recruited into a double-blind controlled trial and randomized to receive either a new no added iron formula (New; <0.1 mg Fe 100 ml(-1)) or a standard formula (Standard; 0.5 mg Fe 100 ml(-1)) for the first 3 mo of life. A breastfed reference group was also studied. Iron status was assessed at 3 and 12 mo from heel-prick capillary blood samples evaluated by full blood-count analysis, including reticulocytes and serum ferritin. In total, 149 infants were entered (51 New, 49 Standard, 49 breastfed) with no differences between the groups in gender distribution, birthweight, gestation or numbers completing the study. There were no significant differences between the principal outcome measures: mean values for haemoglobin, mean cell volume and ferritin, between the two formula-fed groups, and the proportion with a haemoglobin level <11 g dl(-1) or ferritin <10 microg l(-1) did not differ.

The use of a "no added iron" infant formula in place of an iron-fortified formula during the first 3 mo of life did not clinically affect iron status at 3 and 12 mo of age. The universal supplementation of formulae with iron during this initial period needs further consideration.