Summary of findings 2. Intermittent versus daily use of iron supplements in children younger than 12 years of age.

Patient or population: children under 12 years of age Settings: community settings Intervention: intermittent supplementation with iron alone or with other micronutrients Comparison: daily supplementation with iron alone or with other micronutrients
Outcomes	Relative effect (95% CI)	No of Participants (studies)	Quality of the evidence (GRADE)
Anaemia (haemoglobin below a cut‐off defined by trialists, taking into account the age and altitude)	RR 1.23 (1.04–1.47)	980 (6 studies)	⊕⊕⊝⊝ low1,2
Haemoglobin (g/L)	MD –0.60 (–1.54‐0.35)	2851 (19 studies)	⊕⊕⊝⊝ low1,3
Iron deficiency (using ferritin concentrations)	RR 4.00 (1.23–13.05)	76 (1 study)	⊝⊝⊝⊝ very low4
Iron status (ferritin (µg/L)	MD –4.19 (–9.42‐ 1.05)	902 (10 studies)	⊕⊕⊝⊝ low1 3
Iron deficiency anaemia	Not estimable	0 (0 studies)	None of the trials reported on this outcome
Mortality	Not estimable	0 (0 studies)	None of the trials reported on this outcome
CI, confidence interval; RR, risk ratio; MD, mean difference. *GRADE Working Group grades of evidence: High quality: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate quality: We have moderate confidence in the effect estimate. The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low quality: Our confidence in the effect estimate is limited. The true effect may be substantially different from the estimate of the effect. Very low quality: We have very little confidence in the effect estimate. The true effect is likely to be substantially different from the estimate of the effect.
1 Some studies lacked blinding and clear methods of allocation. 2 Wide confidence intervals. 3 High heterogeneity but results were mostly consistent. 4 Only one trial with unclear methods to generate the random sequence and conceal the allocation. Wide confidence intervals. Note: For cluster‐randomised trials the analyses only include the estimated effective sample size, after adjusting the data to account for the clustering effect.