Table 3.
Summary of results for iron fortification in children
| Outcome/quality of evidence | Combined effect |
Population |
Age groups |
Country |
Fortificant type |
Food vehicle |
||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| General/healthy population (studies/ participants) | Deficient population | Infants | Preschool and school- going children | Low- and lower middle income countries | Upper middle- and higher-income countries | Ferrous sulfate | NaFeEDTA | Processed food | Staples | Condiments | ||
|
Hemoglobin levels |
SMD: 0.55 (95% CI: 0.34, 0.76) |
SMD: 0.50 (95% CI: 0.28, 0.71) |
SMD: 0.79 (95% CI: 0.19, 1.38) |
SMD: 0.81 (95% CI: 0.31, 1.31) |
SMD: 0.46 (95% CI: 0.24, 0.67) |
SMD: 0.32 (95% CI: 0.14, 0.50) |
SMD: 0.67 (95% CI: 0.36, 0.97) |
SMD: 0.50 (95% CI: 0.14, 0.86) |
SMD: 0.76 (95% CI: 0.06, 1.47) |
SMD: 0.55 (95% CI: 0.29, 0.82) |
SMD: 0.44 (95% CI: 0.10, 0.79) |
SMD: 1.14 (95% CI: -0.09, 2.37) |
|
Quality of evidence: Moderate |
|
25 studies 5,083 participants |
6 studies 1,184 participants |
12 studies 1,834 participants |
16 studies 3,832 participants |
10 studies 1,937 participants |
20 studies 4,176 participants |
9 studies 1,076 participants |
6 studies 1,172 participants |
18 studies 3,317 participants |
8 studies 1,941 participants |
3 studies 705 participants |
|
Serum ferritin levels |
SMD: 0.91 (95% CI: 0.38, 1.44) |
SMD: 0.63 (95% CI: 0.28, 0.98) |
SMD: 1.37 (95% CI: 0.01, 2.74) |
SMD: 0.63 (95% CI: 0.28, 0.98) |
SMD: 1.37 (95% CI: 0.01, 2.74) |
SMD: 1.37 (95% CI: 0.01, 2.74) |
SMD: 0.68 (95% CI: 0.49, 0.87) |
SMD: 0.84 (95% CI: 0.60, 1.09) |
SMD: 1.83 (95% CI: -0.08, 3.73) |
SMD: 0.66 (95% CI: 0.36, 0.97) |
SMD: 0.48 (95% CI: 0.17, 0.78) |
SMD: 2.80 (95% CI: 2.43, 3.17) |
|
Quality of evidence: Moderate |
|
4 studies 952 participants |
3 studies 555 participants |
4 studies 952 participants |
3 studies 555 participants |
3 studies 555 participants |
3 studies 547 participants |
3 studies 539 participants |
2 studies 385 participants |
5 studies 1,097 participants |
1 study 170 participants |
1 study 240 participants |
|
Effect on anemia |
RR: 0.55 (95% CI: 0.42, 0.72) |
RR: 0.64 (95% CI: 0.50, 0.82) |
RR: 0.23 (95% CI: 0.04, 1.25) |
RR: 0.42 (95% CI: 0.24, 0.72) |
RR: 0.60 (95% CI: 0.43, 0.84) |
RR: 0.91 (95% CI: 0.72, 1.14) |
RR: 0.41 (95% CI: 0.28, 0.61) |
RR: 0.52 (95% CI: 0.34, 0.79) |
RR: 0.46 (95% CI: 0.17, 1.23) |
RR: 0.46 (95% CI: 0.28, 0.76) |
RR: 0.81 (95% CI: 0.60, 1.10) |
RR: 0.12 (95% CI: 0.01, 2.16) |
| Quality of evidence: Moderate | 15 studies 3,096 participants | 3 studies 555 participants | 6 studies 1,234 participants | 10 studies 2,013 participants | 6 studies 1,171 participants | 11 studies 2,396 participants | 4 studies 630 participants | 4 studies 800 participants | 10 studies 1,617 participants | 5 studies 1,312 participants | 2 studies 568 participants | |
Estimates in bold show significant impacts. CI, confidence interval; NaFeEDTA, sodium iron ethylenediaminetetraacetate RR: relative risk; SMD: standard mean difference.