Table 3.

Risk of bias summary for randomized iron-containing intervention studies assessing academic outcomes or dimensions of learning.

Study	Randomization	Intervention Deviations	Missing Data	Outcome Measurement	Selection of Reported Results	Overall
Food-based interventions
Kalaichelvi (2016) [43]	L	H	L	H	L	H
Karkada et al. (2019) [12]	L	H	L	U	H	H
Khan et al. (2004) [44]	L	L	L	L	U	S
Muthayya et al. (2012) [45]	L	L	L	L	L	L
Scott et al. (2018) [46]	L	L	L	L	L	L
Solon et al. (2003) [47]	L	L	L	L	L	L
Sorensen et al. (2015) [14]	L	L	L	L	L	L
Vazir et al. (2006) [15]	L	L	L	L	L	L
Vinodkumar et al. (2009) [48]	L	L	L	L	L	L
Iron-only supplementation interventions
Ballin et al. (1992) [49]	H	H	H	H	U	H
Bruner et al. (1996) [50]	L	L	L	U	U	S
Chellappa and Karunanidhi (2012) [51]	L	L	U	L	U	S
Lambert et al. (2002) [52]	L	U	L	L	U	S
Rezaeian et al. (2014) [53]	L	U	L	L	U	S
Soemantri et al. (1989) [54]	L	H	L	H	U	H
Soemantri et al. (1985) [55]	U	U	U	H	U	H
Umamaheswari et al. (2011) [56]	H	H	U	L	H	H
Iron plus additional micronutrients supplementation interventions
Haskell et al. (2008) [57]	L	L	L	L	L	L
Lynn and Harland (1998) [58]	L	L	L	U	H	H
Nelson et al. (1990) [59]	L	U	L	L	U	S
Schoenthaler et al. (1991) [60]	L	U	H	L	U	H
Sen and Kanani (2009) [13]	L	U	U	L	U	S
Southon et al. (1994) [61]	H	U	L	L	L	H

H—high risk of bias; L—low risk of bias; S—some concerns; U—unclear risk of bias Risk of bias domains: bias arising from the randomization process, bias due to deviations from intended interventions, bias due to missing outcome data, bias in measurement of the outcome, and bias in selection of the reported result.