Background: Vitamin and mineral deficiencies, particularly those of iron, vitamin A and zinc, affect more than two billion people worldwide. Young children are highly vulnerable because of rapid growth and inadequate dietary practices. Micronutrient powders (MNP) are single-dose packets containing multiple vitamins and minerals in powder form that can be sprinkled onto any semi-solid food.The use of MNP for home or point-of-use fortification of complementary foods has been proposed as an intervention for improving micronutrient intake in children under two years of age.
Objectives: To assess the effects and safety of home (point-of-use) fortification of foods with multiple micronutrient powders on nutritional, health and developmental outcomes in children under two years of age.
Search strategy: We searched the following databases in February 2011: Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (1948 to week 2 February 2011), EMBASE (1980 to Week 6 2011), CINAHL (1937 to current), CPCI-S (1990 to 19 February 2011), Science Citation Index (1970 to 19 February 2011), African Index Medicus (searched 23 February 2011), POPLINE (searched 21 February 2011), ClinicalTrials.gov (searched 23 February 2011), mRCT (searched 23 February 2011), and World Health Organization International Clinical Trials Registry Platform (ICTRP) (searched 23 February 2011). We also contacted relevant organisations (25 January 2011) for the identification of ongoing and unpublished studies.
Selection criteria: We included randomised and quasi-randomised trials with either individual or cluster randomisation. Participants were children under the age of two years at the time of intervention, with no specific health problems. The intervention was consumption of food fortified at the point of use with multiple micronutrient powders formulated with at least iron, zinc and vitamin A compared with placebo, no intervention or the use of iron containing supplements, which is the standard practice.
Data collection and analysis: Two review authors independently assessed the eligibility of studies against the inclusion criteria, extracted data from included studies and assessed the risk of bias of the included studies.
Main results: We included eight trials (3748 participants) conducted in low income countries in Asia, Africa and the Caribbean, where anaemia is a public health problem. The interventions lasted between two and 12 months and the powder formulations contained between five and 15 nutrients. Six trials compared the use of MNP versus no intervention or a placebo and the other two compared the use of MNP versus daily iron drops. Most of the included trials were assessed as at low risk of bias.Home fortification with MNP reduced anaemia by 31% (six trials, RR 0.69; 95% CI 0.60 to 0.78) and iron deficiency by 51% (four trials, RR 0.49; 95% CI 0.35 to 0.67) in infants and young children when compared with no intervention or placebo, but we did not find an effect on growth.In comparison with daily iron supplementation, the use of MNP produced similar results on anaemia (one trial, RR 0.89; 95% CI 0.58 to 1.39) and haemoglobin concentrations (two trials, MD -2.36 g/L; 95% CI -10.30 to 5.58); however, given the limited amount of data these results should be interpreted cautiously.No deaths were reported in the trials and information on side effects and morbidity, including malaria, was scarce.It seems that the use of MNP is efficacious among infants and young children six to 23 months of age living in settings with different prevalences of anaemia and malaria endemicity, regardless of whether the intervention lasts two, six or 12 months or whether recipients are male or female.
Authors' conclusions: Home fortification of foods with multiple micronutrient powders is an effective intervention to reduce anaemia and iron deficiency in children six months to 23 months of age. The provision of MNP is better than no intervention or placebo and possibly comparable to commonly used daily iron supplementation. The benefits of this intervention as a child survival strategy or on developmental outcomes are unclear. Data on effects on malaria outcomes are lacking and further investigation of morbidity outcomes is needed. The micronutrient powders containing multiple nutrients are well accepted but adherence is variable and in some cases comparable to that achieved in infants and young children receiving standard iron supplements as drops or syrups.