21. Results of included systematic reviews: infants (aged 6 to 23 months).
| Review | Comparison | Outcome | Number of studies; number of participants | Results | GRADE assessment |
| Supplementation | |||||
|
Abdullah 2013 Efficacy of oral iron therapy in improving the developmental outcome of pre‐school children with non‐anaemic iron deficiency: a systematic review |
Iron supplementation versus no treatment or placebo | Post‐treatment Hb level (g/L) | 2 trials; 68 children | Trial results not combined: MD 11.5, 95% CI 5.1 to 17.9 (P < 0.01); 1 trial, 28 children MD 2.7, 95% CI −1.7 to 7.1; 1 trial, 40 children |
Not assessed |
|
Das 2019a Preventive lipid‐based nutrient supplements given with complementary foods to infants and young children 6 to 23 months of age for health, nutrition, and developmental outcomes |
LNS plus complementary feeding compared with no intervention | Anaemia (Hb < 10 g/dL) | 5 trials: 2332 children | RR 0.79, 95% CI 0.69 to 0.90; significant reduction in anaemia for children receiving LNS plus complementary feeding compared with no intervention | Low |
| Adverse effects Defined as deaths, hospitalisations, congenital abnormalities and life‐threatening conditions requiring an immediate hospital visit | 3 trials: 3382 children | RR 0.86, 95% CI 0.74 to 1.01; no evidence of a difference | Moderate | ||
| LNS plus complementary feeding compared with MNP | Anaemia (Hb < 10 g/dL) | 2 trials: 557 children | RR 0.38, 95% CI 0.21 to 0.68; significant reduction in anaemia for children receiving LNS plus complementary feeding | Low | |
|
Dekker 2010 Zinc supplementation in children is not associated with decreases in hemoglobin concentrations |
Zinc supplementation versus placebo or control | Hb (g/L) | 21 trials; 3869 children | WMD 0.79, 95% CI −0.62 to 2.21; no evidence of a difference | Not assessed |
|
Pasricha 2013 Effect of daily iron supplementation on health in children aged 4‐23 months: a systematic review and meta‐analysis of randomised controlled trials |
Daily oral iron supplements versus control | Hb (g/L) | 26 trials; 5479 children | MD 7.22, 95% CI 4.87 to 9.57 (P < 0.001); significant increase in Hb concentration for children receiving daily iron | Not assessed |
| Anaemia | 17 trials; 4825 children | RR 0.61, 95% CI 0.50 to 0.74 (P < 0.001); significant reduction in anaemia for children receiving daily iron | Not assessed | ||
| IDA | 6 trials; 2145 children | RR 0.14, 95% CI 0.10 to 0.22 (P < 0.001); significant reduction in IDA for children receiving daily iron | Not assessed | ||
| ID | 9 trials; 2464 children | RR 0.30, 95% CI 0.15 to 0.60 (P = 0.001); significant reduction in ID for children receiving daily iron | Not assessed | ||
| Adverse effect: 'any side effect' | 3 trials; 912 children | RR 1.10, 95% CI 0.98 to 1.25; no evidence of a difference | Not assessed | ||
| Adverse effect: 'vomiting' | 3 trials; 1020 children | RR 1.38, 95% CI 1.10 to 1.73 (P = 0.006); significant increase in vomiting for children receiving daily iron | Not assessed | ||
| Adverse effect: 'diarrhoea (prevalence)' | 6 trials; 1697 children | RR 1.03, 95% CI 0.86 to 1.23; no evidence of a difference | Not assessed | ||
| Adverse effect: 'diarrhoea (incidence)' | 5 trials; number of participants: not reported | RR 0.98, 95% CI 0.88 to 1.09; no evidence of a difference | Not assessed | ||
| Adverse effect: 'constipation' | 2 trials; 570 children | RR 0.54, 95% CI 0.05 to 5.83; no evidence of a difference | Not assessed | ||
|
Petry 2016b The effect of low dose iron and zinc intake on child micronutrient status and development during the first 1000 days of life: a systematic review and meta‐analysis |
Children 6 months to 23 months: daily iron administration (≤ 15 mg/day) versus control | Hb (g/L) | 30 trials; 6569 children | MD 4.10,95% CI 2.80 to 5.30 (P < 0.001); significant increase in Hb concentration for children receiving daily iron intervention | Moderate |
| Anaemia | 22 trials; 5647 children | RR 0.59, 95% CI 0.49 to 0.70 (P < 0.001); significant decrease in anaemia for children receiving daily iron intervention | Low | ||
| IDA | 8 trials; 3464 children | RR 0.20, 95% CI 0.11 to 0.37 (P < 0.001); significant decrease in IDA for children receiving daily iron intervention | High | ||
| ID | 13 trials; 3698 children | RR 0.22, 95% CI 0.14 to 0.35 (P < 0.001); significant decrease in ID for children receiving daily iron intervention | High | ||
| Diarrhoea | 8 trials; number of participants: not reported | No beneficial effect of iron on diarrhoea | Not assessed | ||
|
Pratt 2015 A review of the strategies used to reduce the prevalence of iron deficiency and iron deficiency anaemia in infants aged 6‐36 months |
Iron supplementation versus control | Hb (g/L) | 1 trial; 391 children | A statistically significant difference in mean Hb levels for children receiving daily 12.5 mg iron (P = 0.046), but not for the group receiving weekly supplements | Not assessed |
| Anaemia prevalence | 2 trials; 675 children | Trial 1: at 9 months, 21% of infants were anaemic, but no differences between groups for occurrence of anaemia Trial 2: dose–response effect in the group given daily, but not weekly supplements |
Not assessed | ||
| ID | 1 trial; 284 children | At 9 months, 81% of infants had ID, but no differences between groups for occurrence of ID | Not assessed | ||
| Iron‐fortified milk versus control | Hb (g/L) | 1 trial; 115 children | Hb was positively associated with treatment (P < 0.001) | Not assessed | |
| Anaemia prevalence | 2 trials; 910 children | Trial 1: decline from 41.4% to 12.1% in intervention group and no decline in control group Trial 2: decline in intervention group from 44.5% to 12.7% to 4.0%, and in control group from 42.6% to 19.7% to 9.4%, from baseline, to 6 and to 12 months |
Not assessed | ||
| Micronutrient sprinkles versus control | Hb (g/L) | 2 trials; 3633 children | Trial 1: + 6.1 g/L in intervention group compared with + 2.2 g/L in control group, from baseline to 12 and to 18 months, P < 0.001 Trial 2: + 7 g/L in intervention group compared with + 2 g/L in control group, from baseline to 2 months, P < 0.001 |
Not assessed | |
| Anaemia prevalence | 2 trials; 3633 children | Trial 1: reduction of 20.6% in the intervention group (reduction of moderate anaemia by 27.1%), from baseline to 6 months, P < 0.001 Trial 2: reduction from 72% to 52% in the intervention group, increase from 72% to 75% in the control group, from baseline to 2 months, P < 0.001 |
Not assessed | ||
| Food‐based strategies: red meat, fortified cow's milk versus control |
Hb (g/L) | 1 trial; 225 children | No evidence of intervention effects on haemoglobin | Not assessed | |
| Efficacy of different strategies: iron supplement, iron and folic acid supplement, multiple micronutrient supplements, fortified complementary food or fortified water |
Hb (g/L) | 1 trial; 2666 children | All treatments: significant increase in Hb | Not assessed | |
| Anaemia prevalence | 1 trial; 2666 children | Anaemia prevalence significantly more reduced in multiple micronutrient supplement (72%) and iron and folic acid supplementation (69%) groups than fortified complementary food (45%) group | Not assessed | ||
| Fortification | |||||
|
Dewey 2009 Systematic review and meta‐analysis of home fortification of complementary foods |
Home fortification treatment versus iron drops (treatment) | Hb (g/L) | 3 trials; 1263 children | MD −0.91, 95% CI −11.96 to 10.14; no evidence of a difference | Not assessed |
| Anaemia | 3 trials; 1263 children | RR 1.04, 95% CI 0.76 to 1.41; no evidence of a difference | Not assessed | ||
| Diarrhoea | 2 trials; 808 children | SMD −0.34, 95% CI −0.71 to 0.03; no evidence of a difference | Not assessed | ||
| Home fortification versus no intervention or placebo (prevention) | Hb (g/L) | 8 trials; 2649 children | MD 5.06, 95% CI 2.29 to 7.83; significant increase in Hb concentration for children receiving home fortification | Not assessed | |
| Anaemia | 8 trials; 4331 children | RR 0.54, 95% CI 0.46 to 0.64; significant reduction in anaemia for children receiving home fortification | Not assessed | ||
| ID | 3 trials; 1210 children | RR 0.44, 95% CI 0.22 to 0.86; significant reduction in ID for children receiving home fortification | Not assessed | ||
| Diarrhoea | 5 trials; 1195 children | RR 1.07, 95% CI 0.78 to 1.47; no evidence of a difference | Not assessed | ||
|
Eichler 2012 Effects of micronutrient fortified milk and cereal food for infants and children: a systematic review |
Iron fortification of milk and cereals versus non‐fortified food | Hb (g/L) | 13 trials; 2274 children | MD 6.20, 95% CI 3.40 to 8.90; significant increase in Hb concentration for children receiving iron‐fortified milk and cereals | Not assessed |
| Anaemia | 11 trials; 3100 children | RR 0.50, 95% CI 0.33 to 0.75; significant reduction in anaemia for children receiving iron‐fortified milk and cereals | Not assessed | ||
|
Matsuyama 2017 Effect of fortified milk on growth and nutritional status in young children: a systematic review and meta‐analysis |
Fortified milk versus control milk | Hb (g/L) | 9 trials; number of participants: not reported | MD 5.89, 95% CI −0.24 to 12.02; no evidence of a difference | Not assessed |
| Anaemia | 9 trials; number of participants: not reported | OR 0.32, 95% CI 0.15 to 0.66 (P = 0.000); significant reduction in anaemia for children receiving fortified milk | Not assessed | ||
|
Salam 2013 Effectiveness of micronutrient powders (MNP) in women and children |
MNP versus control or no intervention | Hb (g/L) | 14 trials; 9132 children | SMD 0.98, 95% 0.55 to 1.40 (P < 0.001); significant improvement in Hb for children receiving MNP | Moderate |
| Anaemia | 11 trials; 2524 children | RR 0.66, 95% CI 0.57 to 0.77 (P < 0.001); significant reduction in anaemia for children receiving MNP | Moderate | ||
| IDA | 7 trials; 1390 children | RR 0.43, 95% CI 0.35 to 0.52, significant reduction in IDA for children receiving MNP | Moderate | ||
| Diarrhoea | 4 trials; 3371 children | RR 1.04, 95% CI 1.01 to 1.06 (P = 0.002); significant increase in diarrhoea for children receiving MNP | Moderate | ||
| Recurrent diarrhoea | 1 trial; number of participants: not reported | RR 2.86, 95% Cl 0.12 to 69.0; no evidence of a difference | Moderate | ||
|
Suchdev 2020 Home fortification of foods with multiple micronutrient powders for health and nutrition in children under two years of age |
Home (point‐of‐use) fortification of foods with MNP versus no intervention or placebo | Hb (g/L) | 20 trials; 1,050,947 children | MD 2.74, 95% CI 1.95 to 3.53 (P < 0.001); significant increase in Hb concentration for children receiving MNP | Low |
| Anaemia | 16 trials; 9927 children | RR 0.82, 95% CI 0.76 to 0.90 (P < 0.001); significant reduction in anaemia for children receiving MNP | Moderate | ||
| ID | 7 trials; 1634 children | RR 0.47, 95% CI 0.39 to 0.567 (P < 0.001); significant reduction in ID for children receiving MNP | High | ||
| Diarrhoea | 5 trial; 5579 children | OR 1.05, 95% CI 0.82 to 1.35; no evidence of a difference | Not assessed | ||
| Home (point‐of‐use) fortification of foods with MNP versus an iron‐only supplement | Hb (g/L) | 2 trials; 278 children | MD −2.81, 95% CI −10.84 to 5.22; no evidence of a difference | Very low | |
| Anaemia | 1 trial; 145 children | RR 0.89, 95% CI 0.58 to 1.39; no evidence of a difference | Low | ||
| Diarrhoea | 1 trial; 262 children | RR 0.52, 95% CI 0.38 to 0.72 (P < 0.001); significant reduction in diarrhoea for children receiving MNP | Not assessed | ||
| Vomiting | 1 trial; 262 children | RR 0.58, 95% CI 0.35 to 0.95 (P = 0.029); significant reduction in vomiting for children receiving MNP | Not assessed | ||
| Staining of teeth | 2 trials; 395 children | RR 0.37, 95% CI 0.16 to 0.82 (P = 0.02); significant reduction in teeth staining for children receiving MNP | Not assessed | ||
| Stool discolouration | 2 trials; 395 children | RR 0.80, 95% CI 0.66 to 0.98 (P = 0.04); significant reduction in stool discolouration for children receiving MNP | Not assessed | ||
| Improving dietary diversity and quality | |||||
|
Kristjansson 2015 Food supplementation for improving the physical and psychosocial health of socio‐economically disadvantaged children aged three months to five years |
Supplementary feeding versus control | Change in Hb (g/L) | 5 trials; 300 children | SMD 0.49, 95% CI 0.07 to 0.91 (P = 0.002); significant increase in Hb concentration for children receiving supplementary feeding | Not assessed |
|
Shapiro 2019 A systematic review investigating the relation between animal‐source food consumption and stunting in children aged 6‐60 months in low and middle‐income countries |
Caterpillar cereal versus usual diet | Hb (g/dL) | 1 trial; 175 children | Mean (SD) caterpillar cereal: 10.7 (1.6), usual diet: 10.1 (1.8) (P < 0.05) | Not assessed |
| IDA prevalence | 1 trial; 175 children | Caterpillar cereal: 26%, usual diet control: 50% (P < 0.01) | Not assessed | ||
| Beef versus fortified rice‐soy cereal | Hb (g/dL) | 1 trial; 1602 children | No significant difference in Hb levels between intervention and control group | Not assessed | |
| Food fortified with fish powder versus food with or without vitamins and minerals | Hb (g/dL) | 1 trial; 190 children | No significant difference in Hb levels between intervention and control group | Not assessed | |
CI: confidence interval; Hb: haemoglobin; ID: iron deficiency; IDA: iron deficiency anaemia; LNS: lipid‐based nutrient supplements; MD: mean difference; MNP: micronutrient powders; OR: odds ratio; RR: risk ratio; SMD: standard mean difference; WMD: weighted mean difference.