Study Objective
This randomized, double-blinded clinical trial aimed to assess whether daily multivitamin supplements containing iron (10 mg/day) could prevent iron deficiency and anemia in healthy, full-term, low-income infants in an urban U.S. population. The researchers focused on infants considered at high risk due to socioeconomic and nutritional factors.
Methods
- Study Design:
A pragmatic, randomized, double-blind, controlled trial.
Conducted at three urban pediatric clinics serving low-income communities.
Infants were enrolled during their 6-month well-child visit.
- Participants:
Total number enrolled: 284 infants (146 intervention, 138 control).
Inclusion criteria: healthy, full-term infants.
Exclusion criteria: chronic disease, prematurity, low birth weight, etc.
- Intervention:
Intervention group: Daily liquid multivitamin with 10 mg elemental iron.
Control group: Identical multivitamin without added iron.
Supplements were administered daily for 3 months, from 6 to 9 months of age.
Primary Outcomes Measured at 9 Months:
Anemia: Hemoglobin (Hb) < 11.0 g/dL.
Iron Deficiency (ID):
Defined initially by ≥1 abnormal iron-related lab test.
More stringent secondary definition required ≥2 abnormal indicators.
Lab tests included MCV (Mean Corpuscular Volume), RDW (Red Cell Distribution Width), Zinc Protoporphyrin (ZPP), serum ferritin, transferrin saturation, and reticulocyte hemoglobin content.
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Results
1. Anemia and Iron Deficiency Prevalence:
Anemia prevalence at 9 months: 21% (58 out of 284 infants).
Iron deficiency (≥1 abnormal test): 229 infants (81%).
Iron deficiency (≥2 abnormal tests): 139 infants (49%).
2. Comparison Between Groups:
Anemia:
Intervention: 22% of 138 infants.
Control: 19% of 144 infants.
No statistically significant difference (p > 0.05).
Iron Deficiency (1 abnormal test):
Intervention: 78% had ID.
Control: 84% had ID.
No statistically significant difference.
Iron Deficiency (2 abnormal tests):
Intervention: 42%.
Control: 55%.
Not statistically significant after adjusting for adherence and maternal anemia.
3. Adherence Effects:
Adherence did not significantly change the outcomes between the iron and non-iron groups.
However, higher adherence (regardless of group) was associated with lower odds of iron-related abnormality:
Adjusted odds ratio (OR): 0.56; 95% CI: 0.41–0.76.
4. Maternal Anemia Impact:
Infants whose mothers were anemic during pregnancy were 2.15 times more likely to have iron-related lab abnormalities:
OR: 2.15; 95% CI: 1.14–4.07.
Discussion
The study did not find a statistically significant protective effect of giving iron-containing multivitamins to infants between 6 and 9 months in preventing anemia or iron deficiency by 9 months of age. This challenges the presumed benefit of routine iron supplementation in high-risk infants without direct evidence of need or confirmed maternal anemia.
Despite this, the findings highlight:
The high prevalence of iron deficiency (81%) even among healthy, full-term, low-income infants.
The limited effect of iron supplementation alone, suggesting that timing and maternal status may be critical.
Maternal anemia and adherence to supplementation as significant independent predictors of infant iron status.
Conclusions
While this study's iron supplementation strategy was not sufficient to prevent anemia or iron deficiency, it underscores the importance of:
Preventing and treating maternal anemia during pregnancy.
Improving infant adherence to supplementation routines.
Further research into early-life interventions and maternal-child nutrition continuity.
Given the consequences of iron deficiency for neurodevelopment and physical growth, especially in low-income settings, policy and clinical strategies must extend beyond postnatal iron supplementation alone.
For full details, refer to the original article: https://pubmed.ncbi.nlm.nih.gov/15231912/
