Home fortification of foods with multiple micronutrient powders for health and nutrition in children under two years of age (Review)

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 methods

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 We also contacted relevant organisations (25 January 2011) for the identification of ongoing and unpublished studies.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.

Plain Language Summary

Use of a powder mix of vitamins and minerals to fortify complementary foods immediately before consumption and improve health and nutrition in children under two years of age

Deficiencies of vitamins and minerals, particularly of iron, vitamin A and zinc, affect approximately half of the infants and young children under two years of age worldwide. Exclusive breastfeeding until six months of age and continued breastfeeding for at least two years are recommended to maintain children's adequate health and nutrition. After six months of age, infants start receiving semi-solid foods but the amount of vitamins and minerals can be insufficient to fulfil all the requirements of the growing baby. Micronutrient powders (MNP) are single-dose packets of powder containing iron, vitamin A, zinc and other vitamins and minerals that can be sprinkled onto any semi-solid food at home or at any other point of use to increase the content of essential nutrients in the infant's diet during this period. This is done without changing the usual baby diet.

This review includes eight good quality trials that involved 3748 infants and young children from low income countries in Asia, Africa and the Caribbean. We found that a variety of MNP formulations containing between five and 15 vitamins and minerals have been given for between two and 12 months to infants and young children aged six to 23 months of age.

The use of MNP containing at least iron, zinc and vitamin A for home fortification of foods was associated with a reduced risk of anaemia and iron deficiency in children under two. The studies did not find any effects on growth. Although the acceptability of this innovative intervention was high, there is no additional benefit to usually recommended iron drops or syrups, however few studies compared these different interventions. No deaths were reported in the trials and information on side effects and morbidity, including malaria, was scarce. The use of MNP was beneficial for male and female infants and young children six to 23 months of age, independent of whether they lived in settings with different anaemia and malaria backgrounds or whether the intervention was provided for two, six or 12 months. The most appropriate arrangements for use (daily or intermittently), the appropriate vitamin and mineral composition of the mix of powders and the way to deliver this intervention effectively in public health programmes to address multiple micronutrient deficiencies remain unclear.