| Micronutrient supplementation/fortification compared with placebo/no supplementation/fortification for health and nutritional status | ||||||
|---|---|---|---|---|---|---|
| Patient or population: Adolescents | ||||||
| Settings: School settings | ||||||
| Intervention: Micronutrient supplementation/fortification | ||||||
| Comparison: Placebo/no supplementation/fortification | ||||||
| Illustrative comparative risks* (95% CI) | ||||||
| Assumed risk | Corresponding risk | |||||
| Outcomes | Placebo/No supplementation/fortification | Micronutrient supplementation/fortification | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments |
| Daily Iron supplementation with or without folic acid: Anaemia | 206 of 579 | 216 of 581 | RR: 1.06 [0.95, 1.18] | 1,160 participants (one study) | ⊕⊕⊝⊝ | |
| Low a , b | ||||||
| Weekly Iron supplementation with or without folic acid: Anaemia | 206 of 579 | 265 of 695 | RR: 1.07 [0.93, 1.24] | 1,274 participants (one study) | ⊕⊕⊝⊝ | |
| Low a , b | ||||||
| Calcium/vitamin D supplementation/fortification: BMI | The mean BMI in the control group ranged between 18.15 and 18.5 | The mean BMI in the intervention group ranged between 17.05 and 19.1 | MD: −0.01 kg/m2 [−1.20, 1.17] | 730 participants (two studies) | ⊕⊝⊝⊝ | |
| Very Low a , b , c | ||||||
| Iron supplementation with or without folic acid: BMI | The mean BMI in the control group ranged between 15.78 and 16.23 | The mean BMI in the intervention group ranged between 15.67 and 17.25 | MD: 0.29 kg/m2 [−0.25, 0.83] | 652 participants (two studies) | ⊕⊝⊝⊝ | |
| Very Low a , b , c | ||||||
| Zinc supplementation: BMI | The mean BMI in the control group ranged was 16.23 | The mean BMI in the intervention group was 16.58 | MD: 0.35 kg/m2 [−0.15, 0.85] | 382 participants (one study) | ⊕⊝⊝⊝ | |
| Very Low a , b , c | ||||||
| MMN fortification: BMI | The mean BMI in the control group ranged between 15.27 and 16.5 | The mean BMI in the intervention group ranged between 15.42 and 17.1 | MD: 0.23 kg/m2 [−0.11, 0.57] | 943 participants (two studies) | ⊕⊝⊝⊝ | |
| Very Low a , b , c | ||||||
GRADE Working Group grades of evidence: High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate.
Abbreviations: BMI, body mass index; CI, confidence interval; MD, mean difference; MMN, multiple micronutrient; RR, risk ratio.
The basis for the assumed risk (e.g., the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
Downgraded due to very serious study limitations.
Downgraded by one level due to imprecision.
Downgraded by one level due to high heterogeneity.