Table 7 Summary of results for iron, folate and calcium/vitamin D fortification in women
From: Micronutrient fortification of food and its impact on woman and child health: a systematic review
Iron fortification | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Outcome/quality of evidence | Combined effect | Population | Country | Fortificant type | Food vehicle | |||||
General/healthy population | Deficient population | Low- and lower middle-income countries | Upper middle- and higher-income countries | Ferrous sulfate | NaFeEDTA | Processed food | Staples | Condiments | ||
Hemoglobin levels | SMD: 0.62 (95% CI: 0.36, 0.89) | SMD: 0.66 (95% CI: 0.30, 1.02) | SMD: 0.59 (95% CI: 0.34, 0.83) | SMD: 0.52 (95% CI: -0.12, 1.16) | SMD: 0.66 (95% CI: 0.31, 1.00) | SMD: 0.44 (95% CI: 0.21, 0.67) | SMD: 0.48 (95% CI: 0.22, 0.73) | SMD: 0.50 (95% CI: 0.30, 0.70) | SMD: 0.90 (95% CI: -0.10, 1.90) | SMD: 0.45 (95% CI: 0.22, 0.68) |
Quality of evidence: Moderate | Â | 7 studies 2,819 participants | 4 studies 404 participants | 2 studies 524 participants | 8 studies 2,588 participants | 3 studies 310 participants | 4 studies 1,588 participants | 4 studies 398 participants | 3 studies 1,211 participants | 4 studies 1,614 participants |
Serum ferritin levels | SMD: 0.41 (95% CI: 0.23, 0.60) | SMD: 0.23 (95% CI: 0.08, 0.38) | SMD: 0.75 (95% CI: 0.47, 1.03) | SMD: 0.48 (95% CI: 0.31, 0.66) | SMD: 0.39 (95% CI: 0.17, 0.61) | SMD: 0.42 (95% CI: 0.05, 0.78) | SMD: 0.45 (95% CI: 0.21, 0.69) | SMD: 0.46 (95% CI: 0.10, 0.82) | SMD: 0.17 (95% CI: -0.15, 0.49) | SMD: 0.50 (95% CI: 0.33, 0.68) |
Quality of evidence: Low | Â | 6 studies 2,609 participants | 4 studies 400 participants | 2 studies 525 participants | 8 studies 2,484 participants | 1 study 117 participants | 4 studies 1,559 participants | 5 studies 1,390 participants | to 2 studies 993 participants | 3 studies 626 participants |
Effect on anemia | RR: 0.68 (95% CI: 0.49, 0.93) | RR: 0.65 (95% CI: 0.40, 1.04) | RR: 0.74 (95% CI: 0.61, 0.90) | RR: 0.74 (95% CI: 0.61, 0.90) | RR: 0.67 (95% CI: 0.39, 1.17) | RR: 0.57 (95% CI: 0.34, 0.94) | RR: 0.74 (95% CI: 0.61, 0.90) | RR: 0.51 (95% CI: 0.21, 1.25) | RR: 0.67 (95% CI: 0.39, 1.17) | RR: 0.74 (95% CI: 0.61, 0.90) |
Quality of evidence: Low | Â | 3 studies 1,180 participants | 1 study 136 participants | 1 study 136 participants | 2 studies 1,056 participants | 2 studies 199 participants | 1 study 136 participants | 1 study 124 participants | 2 studies 1,056 participants | 1 study 136 participants |
Folate fortification | ||||||||||
Outcome/quality of evidence | Combined effect | Quantity | Duration | |||||||
40 μg/100 g | More than 100 μg/100 g | Less than 1 year | Greater than 1 year | |||||||
Neural tube defects | RR: 0.57 (95% CI: 0.45, 0.73) | RR: 0.80 (95% CI: 0.75, 0.86) | RR: 0.55 (95% CI: 0.41, 0.75) | RR: 0.52 (95% CI: 0.28, 0.97) | RR: 0.60 (95% CI: 0.50, 0.72) | |||||
Quality of evidence: Moderate | Â | 3 studies | 2 studies | 3 studies | 4 studies | |||||
Spina bifida | RR: 0.64 (95% CI: 0.57, 0.71) | RR: 0.72 (95% CI: 0.65, 0.80) | RR: 0.51 (95% CI: 0.41, 0.65) | RR: 0.72 (95% CI: 0.65, 0.80) | RR: 0.56 (95% CI: 0.49, 0.65) | |||||
Quality of evidence: Moderate | Â | 6 studies | 3 studies | 3 studies | 7 studies | |||||
Anencephaly | RR: 0.76 (95% CI: 0.68, 0.85) | RR: 0.81 (95% CI: 0.74, 0.88) | RR: 0.67 (95% CI: 0.43, 1.04) | RR: 0.85 (95% CI: 0.79, 0.93) | RR: 0.70 (95% CI: 0.59, 0.83) | |||||
Quality of evidence: Moderate | Â | 6 studies | 2 studies | 3 studies | 7 studies | |||||
Serum folate levels | SMD: 1.38 (95% CI: -0.20, 2.95) | No studies identified | No studies identified | SMD: 1.65 (95% CI: -0.51, 3.82) | SMD: 0.45 (95% CI: -0.06, 0.97) | |||||
Quality of evidence: Low | Â | Â | Â | 3 studies | 2 studies | |||||
Iodine fortification | ||||||||||
Outcome/quality of evidence | Combined effect | |||||||||
Effect on hypothyroidism | RR: 1.42 (95% CI: 1.11, 1.82) | |||||||||
Quality of evidence: Low | 2 studies | |||||||||
Urinary iodine concentrations | SMD: 7.16 (95% CI: 1.00, 13.31) | |||||||||
Quality of evidence: Moderate | 4 studies | |||||||||
Calcium and vitamin D fortification | ||||||||||
Outcome/quality of evidence | Women of reproductive age | Post-menopausal women | ||||||||
Vitamin D only | Calcium and vitamin D | Calcium only | Vitamin D only | |||||||
Serum parathyroid hormone levels | SMD: 0.10 (95% CI: -0.28, 0.48) | SMD: -0.23 (95% CI: -0.78, 0.32) | No studies identified | No studies identified | ||||||
Quality of evidence: Low | 2 studies 108 participants | 1 study 52 participants | Â | Â | ||||||
Serum vitamin D levels | SMD: 0.26 (95% CI: -0.22, 0.75) | SMD: -2.50 (95% CI: -3.22, -1.78) | SMD: 0.69 (95% CI: 0.38, 1.00) | No studies identified | ||||||
Quality of evidence: Moderate | 1 study 66 participants | 1 study 55 participants | 3 studies 228 | Â | ||||||