Am Fam Physician. 2004;70(9):1762-1764
Clinical Question: Does prophylactic administration of iron prevent the development of anemia in infants?
Setting: Outpatient (primary care)
Study Design: Randomized controlled trial (double-blinded)
Synopsis: Investigators enrolled 376 healthy, full-term infants at their six-month well-child visit. Approximately 90 percent of the mothers received supplemental nutrition vouchers through the Special Supplemental Nutrition Program for Women, Infants, and Children, and 43 percent of the mothers were anemic during pregnancy. Iron status of the infants was not determined at the initial visit. The children were randomized (allocation concealed) to receive a multivitamin with or without 10 mg of elemental iron for three months.
Approximately 74 percent of the children were available three to six months later for follow-up. At this visit, 84 percent of the children were anemic (21 percent of total) or possibly iron deficient (defined by the number of indices, other than hemoglobin levels, that were abnormal). The proportion of the children in either group who developed anemia was not statistically different, nor were there any differences in any specific measure of anemia. The presence of anemia at nine to 12 months of age correlated with maternal anemia during pregnancy. The results were similar when including all patients, whether or not they were fully adherent to therapy (intention-to-treat analysis), or when analyzing only children who received iron daily. Because the children may have been anemic at the start of the study, another interpretation may be that 10 mg of iron is not sufficient to replete iron levels in children with anemia.
Bottom Line: Routine iron supplementation in infants, starting at six months of age, does not affect the prevalence of anemia when evaluated at the nine-month visit. In this study, anemia in infants was related to maternal anemia during pregnancy, which was present in 43 percent of the mothers in this sample. Therefore, the children were likely to have been anemic since birth. (Level of Evidence: 1b)