Fortification of maize meal improved the nutritional status of 1-3-year-old African children

Health outcomes associated with micronutrient-fortified complementary foods in infants and young children aged 6–23 months: a systematic review and meta-analysis

Background

Appropriate feeding of infants and young children is essential for healthy growth and the prevention of stunting, wasting, and overweight. We aimed to assess the beneficial versus harmful effects of providing fortified complementary foods to children in the complementary feeding period.

Methods

In this systematic review and meta-analysis, we searched the databases Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, Global Index Medicus, Web of Science, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform from inception to March 9, 2021. We included randomised controlled trials and controlled clinical trials done in infants and children aged 6–23 months with no identified health problems. Consumption of foods fortified centrally (ie, during industrial processing) with one micronutrient or a combination of vitamins, minerals, or both was compared with the same complementary foods, but without micronutrient fortification. Two review authors independently screened studies for eligibility, extracted data, assessed risk of bias, and rated the certainty of the evidence. The main outcomes were growth (measured by Z scores for weight for age, weight for height or length, and height or length for age, or other growth measures), stunting, wasting, nutrient adequacy or excess, anaemia, haemoglobin concentration, iron status, serum zinc concentration, and serum retinol concentration. We used a random-effects meta-analysis for combining data. This study is registered with PROSPERO, CRD42021245876.

Findings

We included 16 studies with 6423 participants, 13 of which were done in malaria-endemic areas. Overall, 12 studies were included in the quantitative syntheses. We identified five further ongoing studies. There was no difference between participants who received fortified complementary foods and those who received non-fortified complementary foods in weight-for-age Z scores (mean difference −0·01, 95% CI −0·07 to 0·06; five trials; 1206 participants; moderate-certainty evidence), weight-for-height or length Z scores (−0·05, −0·19 to 0·10; four trials; 1109 participants; moderate-certainty evidence), and height or length-for-age Z scores (−0·01, −0·21 to 0·20; four trials; 811 participants; low-certainty evidence); stunting and wasting were not assessed in any study as outcomes. Moderate-certainty evidence from six trials with 1209 patients showed that providing fortified complementary foods to children aged 6–23 months reduced the risk of anaemia (risk ratio 0·57, 95% CI 0·39 to 0·82). Those who received fortified complementary foods compared with those who did not had higher haemoglobin concentrations (mean difference 3·44 g/L, 95% CI 1·33 to 5·55; 11 trials; 2175 participants; moderate-certainty evidence) and ferritin concentration (0·43 μg/L on log scale, 0·14 to 0·72; six trials; 903 participants; low-certainty evidence). The intervention led to no effects on serum zinc concentration (−0·13 g/dL, −0·82 to 0·56; two trials; 333 participants; low-certainty evidence) and serum retinol concentration (0·03 μmol/L, −0·02 to 0·08; five trials; 475 participants; moderate-certainty evidence).

Interpretation

Fortified complementary foods are effective strategies to prevent anaemia in infants and young children aged 6–23 months in malaria-endemic regions. Effects of complementary food fortification should be further investigated in low-income and middle-income countries, but should also be assessed in high-income countries, and in regions where malaria is not endemic.

Funding

WHO.

Rice: a potential vehicle for micronutrient fortification

The choices of consumer towards food have been changed. Consumer prefers to eat food which is not only safe but also nutritious. Now a day, they like to eat the food which promote their health and help in minimizing nutrition related health hazards. Rice is a staple food in many countries, but most emerging issue is that rice is deficit in minerals. Rice ranks second among cereals in dietary uses around the world. Rice is deficit in iron (Fe) zinc (Zn) and these are important micronutrients for infants, men and women. Fortification of rice with iron and zinc would help to minimize nutrient deficient disorders among humans. Present study is aimed to introduce nutrients rich rice for consumers and also to encourage food-fortification organizations for diverting their focus on rice fortification. In south Asian countries, micronutrient deficiency especially Fe and Zn deficiency is very common. The rice because of its use as a staple food can be utilized as a carrier medium for transporting micronutrients from plants sources to human beings. Hence, rice fortification with microminerals can prove as a miracle for the virtual eradication of nutrition related diseases in humans.

Food fortification with multiple micronutrients: impact on health outcomes in general population

BACKGROUND

Vitamins and minerals are essential for growth and maintenance of a healthy body, and have a role in the functioning of almost every organ. Multiple interventions have been designed to improve micronutrient deficiency, and food fortification is one of them.

OBJECTIVES

To assess the impact of food fortification with multiple micronutrients on health outcomes in the general population, including men, women and children.

SEARCH METHODS

We searched electronic databases up to 29 August 2018, including the Cochrane Central Register of Controlled Trial (CENTRAL), the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register and Cochrane Public Health Specialised Register; MEDLINE; Embase, and 20 other databases, including clinical trial registries. There were no date or language restrictions. We checked reference lists of included studies and relevant systematic reviews for additional papers to be considered for inclusion.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-RCTs, quasi-randomised trials, controlled before-after (CBA) studies and interrupted time series (ITS) studies that assessed the impact of food fortification with multiple micronutrients (MMNs). Primary outcomes included anaemia, micronutrient deficiencies, anthropometric measures, morbidity, all-cause mortality and cause-specific mortality. Secondary outcomes included potential adverse outcomes, serum concentration of specific micronutrients, serum haemoglobin levels and neurodevelopmental and cognitive outcomes. We included food fortification studies from both high-income and low- and middle-income countries (LMICs).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened, extracted and quality-appraised the data from eligible studies. We carried out statistical analysis using Review Manager 5 software. We used random-effects meta-analysis for combining data, as the characteristics of study participants and interventions differed significantly. We set out the main findings of the review in 'Summary of findings' tables, using the GRADE approach.

MAIN RESULTS

We identified 127 studies as relevant through title/abstract screening, and included 43 studies (48 papers) with 19,585 participants (17,878 children) in the review. All the included studies except three compared MMN fortification with placebo/no intervention. Two studies compared MMN fortification versus iodised salt and one study compared MMN fortification versus calcium fortification alone. Thirty-six studies targeted children; 20 studies were conducted in LMICs. Food vehicles used included staple foods, such as rice and flour; dairy products, including milk and yogurt; non-dairy beverages; biscuits; spreads; and salt. Fourteen of the studies were fully commercially funded, 13 had partial-commercial funding, 14 had non-commercial funding and two studies did not specify the source of funding. We rated all the evidence as of low to very low quality due to study limitations, imprecision, high heterogeneity and small sample size. When compared with placebo/no intervention, MMN fortification may reduce anaemia by 32% (risk ratio (RR) 0.68, 95% confidence interval (CI) 0.56 to 0.84; 11 studies, 3746 participants; low-quality evidence), iron deficiency anaemia by 72% (RR 0.28, 95% CI 0.19 to 0.39; 6 studies, 2189 participants; low-quality evidence), iron deficiency by 56% (RR 0.44, 95% CI 0.32 to 0.60; 11 studies, 3289 participants; low-quality evidence); vitamin A deficiency by 58% (RR 0.42, 95% CI 0.28 to 0.62; 6 studies, 1482 participants; low-quality evidence), vitamin B2 deficiency by 64% (RR 0.36, 95% CI 0.19 to 0.68; 1 study, 296 participants; low-quality evidence), vitamin B6 deficiency by 91% (RR 0.09, 95% CI 0.02 to 0.38; 2 studies, 301 participants; low-quality evidence), vitamin B12 deficiency by 58% (RR 0.42, 95% CI 0.25 to 0.71; 3 studies, 728 participants; low-quality evidence), weight-for-age z-scores (WAZ) (mean difference (MD) 0.1, 95% CI 0.02 to 0.17; 8 studies, 2889 participants; low-quality evidence) and weight-for-height/length z-score (WHZ/WLZ) (MD 0.1, 95% CI 0.02 to 0.18; 6 studies, 1758 participants; low-quality evidence). We are uncertain about the effect of MMN fortification on zinc deficiency (RR 0.84, 95% CI 0.65 to 1.08; 5 studies, 1490 participants; low-quality evidence) and height/length-for-age z-score (HAZ/LAZ) (MD 0.09, 95% CI 0.01 to 0.18; 8 studies, 2889 participants; low-quality evidence). Most of the studies in this comparison were conducted in children. Subgroup analyses of funding sources (commercial versus non-commercial) and duration of intervention did not demonstrate any difference in effects, although this was a relatively small number of studies and the possible association between commercial funding and increased effect estimates has been demonstrated in the wider health literature. We could not conduct subgroup analysis by food vehicle and funding; since there were too few studies in each subgroup to draw any meaningful conclusions. When we compared MMNs versus iodised salt, we are uncertain about the effect of MMN fortification on anaemia (R 0.86, 95% CI 0.37 to 2.01; 1 study, 88 participants; very low-quality evidence), iron deficiency anaemia (RR 0.40, 95% CI 0.09 to 1.83; 2 studies, 245 participants; very low-quality evidence), iron deficiency (RR 0.98, 95% CI 0.82 to 1.17; 1 study, 88 participants; very low-quality evidence) and vitamin A deficiency (RR 0.19, 95% CI 0.07 to 0.55; 2 studies, 363 participants; very low-quality evidence). Both of the studies were conducted in children. Only one study conducted in children compared MMN fortification versus calcium fortification. None of the primary outcomes were reported in the study. None of the included studies reported on morbidity, adverse events, all-cause or cause-specific mortality.

AUTHORS' CONCLUSIONS

The evidence from this review suggests that MMN fortification when compared to placebo/no intervention may reduce anaemia, iron deficiency anaemia and micronutrient deficiencies (iron, vitamin A, vitamin B2 and vitamin B6). We are uncertain of the effect of MMN fortification on anthropometric measures (HAZ/LAZ, WAZ and WHZ/WLZ). There are no data to suggest possible adverse effects of MMN fortification, and we could not draw reliable conclusions from various subgroup analyses due to a limited number of studies in each subgroup. We remain cautious about the level of commercial funding in this field, and the possibility that this may be associated with higher effect estimates, although subgroup analysis in this review did not demonstrate any impact of commercial funding. These findings are subject to study limitations, imprecision, high heterogeneity and small sample sizes, and we rated most of the evidence low to very low quality. and hence no concrete conclusions could be drawn from the findings of this review.

Improved micronutrient status and health outcomes in low- and middle-income countries following large-scale fortification: evidence from a systematic review and meta-analysis

BACKGROUND

Micronutrient malnutrition is highly prevalent in low- and middle-income countries (LMICs) and disproportionately affects women and children. Although the effectiveness of large-scale food fortification (LSFF) of staple foods to prevent micronutrient deficiencies in high-income settings has been demonstrated, its effectiveness in LMICs is less well characterized. This is important as food consumption patterns, potential food vehicles, and therefore potential for impact may vary substantially in these contexts.

OBJECTIVES

The aim of this study was to determine the real-world impact of LSFF with key micronutrients (vitamin A, iodine, iron, folic acid) on improving micronutrient status and functional health outcomes in LMICs.

METHODS

All applicable published/unpublished evidence was systematically retrieved and analyzed. Studies were not restricted by age or sex. Meta-analyses were performed for quantitative outcomes and results were presented as summary RRs, ORs, or standardized mean differences (SMDs) with 95% CIs.

RESULTS

LSFF increased serum micronutrient concentrations in several populations and demonstrated a positive impact on functional outcomes, including a 34% reduction in anemia (RR: 0.66; 95% CI: 0.59, 0.74), a 74% reduction in the odds of goiter (OR: 0.26; 95% CI: 0.16, 0.43), and a 41% reduction in the odds of neural tube defects (OR: 0.59; 95% CI: 0.49, 0.70). Additionally, we found that LSFF with vitamin A could protect nearly 3 million children per year from vitamin A deficiency. We noted an age-specific effect of fortification, with women (aged >18 y) attaining greater benefit than children, who may consume smaller quantities of fortified staple foods. Several programmatic/implementation factors were also reviewed that may facilitate or limit program potential.

CONCLUSIONS

Measurable improvements in the micronutrient and health status of women and children are possible with LSFF. However, context and implementation factors are important when assessing programmatic sustainability and impact, and data on these are quite limited in LMIC studies.

Fortification of staple foods with vitamin A for vitamin A deficiency

BACKGROUND

Vitamin A deficiency is a significant public health problem in many low- and middle-income countries, especially affecting young children, women of reproductive age, and pregnant women. Fortification of staple foods with vitamin A has been used to increase vitamin A consumption among these groups.

OBJECTIVES

To assess the effects of fortifying staple foods with vitamin A for reducing vitamin A deficiency and improving health-related outcomes in the general population older than two years of age.

SEARCH METHODS

We searched the following international databases with no language or date restrictions: Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 6) in the Cochrane Library; MEDLINE and MEDLINE In Process OVID; Embase OVID; CINAHL Ebsco; Web of Science (ISI) SCI, SSCI, CPCI-exp and CPCI-SSH; BIOSIS (ISI); POPLINE; Bibliomap; TRoPHI; ASSIA (Proquest); IBECS; SCIELO; Global Index Medicus - AFRO and EMRO; LILACS; PAHO; WHOLIS; WPRO; IMSEAR; IndMED; and Native Health Research Database. We also searched clinicaltrials.gov and the International Clinical Trials Registry Platform to identify ongoing and unpublished studies. The date of the last search was 19 July 2018.

SELECTION CRITERIA

We included individually or cluster-randomised controlled trials (RCTs) in this review. The intervention included fortification of staple foods (sugar, edible oils, edible fats, maize flour or corn meal, wheat flour, milk and dairy products, and condiments and seasonings) with vitamin A alone or in combination with other vitamins and minerals. We included the general population older than two years of age (including pregnant and lactating women) from any country.

DATA COLLECTION AND ANALYSIS

Two authors independently screened and assessed eligibility of studies for inclusion, extracted data from included studies and assessed their risk of bias. We used standard Cochrane methodology to carry out the review.

MAIN RESULTS

We included 10 randomised controlled trials involving 4455 participants. All the studies were conducted in low- and upper-middle income countries where vitamin A deficiency was a public health issue. One of the included trials did not contribute data to the outcomes of interest.Three trials compared provision of staple foods fortified with vitamin A versus unfortified staple food, five trials compared provision of staple foods fortified with vitamin A plus other micronutrients versus unfortified staple foods, and two trials compared provision of staple foods fortified with vitamin A plus other micronutrients versus no intervention. No studies compared staple foods fortified with vitamin A alone versus no intervention.The duration of interventions ranged from three to nine months. We assessed six studies at high risk of bias overall. Government organisations, non-governmental organisations, the private sector, and academic institutions funded the included studies; funding source does not appear to have distorted the results.Staple food fortified with vitamin A versus unfortified staple food We are uncertain whether fortifying staple foods with vitamin A alone makes little or no difference for serum retinol concentration (mean difference (MD) 0.03 μmol/L, 95% CI -0.06 to 0.12; 3 studies, 1829 participants; I² = 90%, very low-certainty evidence). It is uncertain whether vitamin A alone reduces the risk of subclinical vitamin A deficiency (risk ratio (RR) 0.45, 95% CI 0.19 to 1.05; 2 studies; 993 participants; I² = 33%, very low-certainty evidence). The certainty of the evidence was mainly affected by risk of bias, imprecision and inconsistency.It is uncertain whether vitamin A fortification reduces clinical vitamin A deficiency, defined as night blindness (RR 0.11, 95% CI 0.01 to 1.98; 1 study, 581 participants, very low-certainty evidence). The certainty of the evidence was mainly affected by imprecision, inconsistency, and risk of bias.Staple foods fortified with vitamin A versus no intervention No studies provided data for this comparison.Staple foods fortified with vitamin A plus other micronutrients versus same unfortified staple foods Fortifying staple foods with vitamin A plus other micronutrients may not increase the serum retinol concentration (MD 0.08 μmol/L, 95% CI -0.06 to 0.22; 4 studies; 1009 participants; I² = 95%, low-certainty evidence). The certainty of the evidence was mainly affected by serious inconsistency and risk of bias.In comparison to unfortified staple foods, fortification with vitamin A plus other micronutrients probably reduces the risk of subclinical vitamin A deficiency (RR 0.27, 95% CI 0.16 to 0.49; 3 studies; 923 participants; I² = 0%; moderate-certainty evidence). The certainty of the evidence was mainly affected by serious risk of bias.Staple foods fortified with vitamin A plus other micronutrients versus no interventionFortification of staple foods with vitamin A plus other micronutrients may increase serum retinol concentration (MD 0.22 μmol/L, 95% CI 0.15 to 0.30; 2 studies; 318 participants; I² = 0%; low-certainty evidence). When compared to no intervention, it is uncertain whether the intervention reduces the risk of subclinical vitamin A deficiency (RR 0.71, 95% CI 0.52 to 0.98; 2 studies; 318 participants; I² = 0%; very low-certainty evidence) . The certainty of the evidence was affected mainly by serious imprecision and risk of bias.No trials reported on the outcomes of all-cause morbidity, all-cause mortality, adverse effects, food intake, congenital anomalies (for pregnant women), or breast milk concentration (for lactating women).

AUTHORS' CONCLUSIONS

Fortifying staple foods with vitamin A alone may make little or no difference to serum retinol concentrations or the risk of subclinical vitamin A deficiency. In comparison with provision of unfortified foods, provision of staple foods fortified with vitamin A plus other micronutrients may not increase serum retinol concentration but probably reduces the risk of subclinical vitamin A deficiency.Compared to no intervention, staple foods fortified with vitamin A plus other micronutrients may increase serum retinol concentration, although it is uncertain whether the intervention reduces the risk of subclinical vitamin A deficiency as the certainty of the evidence has been assessed as very low.It was not possible to estimate the effect of staple food fortification on outcomes such as mortality, morbidity, adverse effects, congenital anomalies, or breast milk vitamin A, as no trials included these outcomes.The type of funding source for the studies did not appear to distort the results from the analysis.

Thiamin deficiency in low- and middle-income countries: Disorders, prevalences, previous interventions and current recommendations

BACKGROUND

Thiamin deficiency is a major public health concern in several low- and middle-income countries (LMICs)-current attention to the problem is lacking.

AIM

This review discusses prevalence of thiamin insufficiency and thiamin-deficiency disorders (TDDs) in LMICs, outlines programmatic experience with thiamin interventions, and offers recommendations to improve public-health and research attention to thiamin in LMICs.

DISCUSSION

Thiamin insufficiency, i.e. low-blood-thiamin status, is endemic among several Southeast Asian countries: Cambodia (70-100% of infants and 27-100% of reproductive-age women); Laos (13% of hospitalized infants); Thailand (16-25% of children and 30% of elderly adults). Thiamin deficiency accounts for up to 45% of under-5 deaths in Cambodia, 34% of infant deaths in Laos, and 17% of infant deaths in Myanmar. Deficiency also exists in Africa, Asia, and the Americas, but these instances have typically been isolated. Exclusively breastfed infants of thiamin-deficient mothers are at highest risk for TDD and related death. Intervention strategies that have been employed to combat thiamin deficiency include food processing, fortification, supplementation, dietary diversification, and dietary behaviors, all of which have shown varying levels of effectiveness.

CONCLUSIONS

We recommend universal thiamin-fortification of context-specific staple-foods in LMICs as a promising solution, as well as thiamin supplementation, particularly for pregnant and lactating women. Food processing regulations, dietary diversification, and modification of dietary behaviors to increase consumption of thiamin-rich foods may provide benefits in some circumstances, especially in countries without universal fortification programs or in populations dependent on food aid.

Fortification of maize flour with iron for controlling anaemia and iron deficiency in populations

BACKGROUND

Approximately 800 million women and children have anaemia, a condition thought to cause almost 9% of the global burden of years lived with disability. Around half this burden could be amenable to interventions that involve the provision of iron. Maize (corn) is one of the world's most important cereal grains and is cultivated across most of the globe. Several programmes around the world have fortified maize flour and other maize-derived foodstuffs with iron and other vitamins and minerals to combat anaemia and iron deficiency.

OBJECTIVES

To assess the effects of iron fortification of maize flour, corn meal and fortified maize flour products for anaemia and iron status in the general population.

SEARCH METHODS

We searched the following international and regional sources in December 2017 and January 2018: Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; MEDLINE (R) In Process; Embase; Web of Science (both the Social Science Citation Index and the Science Citation Index); CINAHL Ebsco; POPLINE; AGRICOLA (agricola.nal.usda.gov); BIOSIS (ISI); Bibliomap and TRoPHI; IBECS; Scielo; Global Index Medicus - AFRO (includes African Index Medicus); EMRO (includes Index Medicus for the Eastern Mediterranean Region); LILACS; PAHO (Pan American Health Library); WHOLIS (WHO Library); WPRO (includes Western Pacific Region Index Medicus); IMSEAR, Index Medicus for the South-East Asian Region; IndMED, Indian medical journals; and the Native Health Research Database. We searched clinicaltrials.gov and the International Clinical Trials Registry Platform (ICTRP) for any ongoing or planned studies on 17 January 2018 and contacted authors of such studies to obtain further information or eligible data if available.For assistance in identifying ongoing or unpublished studies, we also contacted relevant international organisations and agencies working in food fortification on 9 August 2016.

SELECTION CRITERIA

We included cluster- or individually randomised controlled trials and observational studies. Interventions included (central/industrial) fortification of maize flour or corn meal with iron alone or with other vitamins and minerals and provided to individuals over 2 years of age (including pregnant and lactating women) from any country.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of studies for inclusion, extracted data from included studies and assessed the risk of bias of the included studies. Trial designs with a comparison group were included to assess the effects of interventions. Trial designs without a control or comparison group (uncontrolled before-and-after studies) were included for completeness but were not considered in assessments of the overall effectiveness of interventions or used to draw conclusions regarding the effects of interventions in the review.

MAIN RESULTS

Our search yielded 4529 records. After initial screening of titles and abstracts, we reviewed the full text of 75 studies (80 records). We included 5 studies and excluded 70. All the included studies assessed the effects of providing maize products fortified with iron plus other vitamins and minerals versus unfortified maize flour. No studies compared this intervention to no intervention or looked at the relative effect of flour and products fortified with iron alone (without other vitamins and minerals). Three were randomised trials involving 2610 participants, and two were uncontrolled before-and-after studies involving 849 participants.Only three studies contributed data for the meta-analysis and included children aged 2 to 11.9 years and women. Compared to unfortified maize flour, it is uncertain whether fortifying maize flour or corn meal with iron and other vitamins and minerals has any effect on anaemia (risk ratio (RR) 0.90, 95% confidence interval (CI) 0.58 to 1.40; 2 studies; 1027 participants; very low-certainty evidence), or on the risk of iron deficiency (RR 0.75, 95% CI 0.49 to 1.15; 2 studies; 1102 participants; very low-certainty evidence), haemoglobin concentration (mean difference (MD) 1.25 g/L, 95% CI -2.36 to 4.86 g/L; 3 studies; 1144 participants; very low-certainty evidence) or ferritin concentrations (MD 0.48 µg/L, 95% CI -0.37 to 1.33 µg/L; 1 study; 584 participants; very low-certainty evidence).None of the studies reported on any adverse effects. We judged the certainty of the evidence to be very low based on GRADE, so we are uncertain whether the results reflect the true effect of the intervention. We downgraded evidence due to high risk of selection bias and unclear risk of performance bias in one of two included studies, high heterogeneity and wide CIs crossing the line of no effect for anaemia prevalence and haemoglobin concentration.

AUTHORS' CONCLUSIONS

It is uncertain whether fortifying maize flour with iron and other vitamins and minerals reduces the risk of anaemia or iron deficiency in children aged over 2 years or in adults. Moreover, the evidence is too uncertain to conclude whether iron-fortified maize flour, corn meal or fortified maize flour products have any effect on reducing the risk of anaemia or on improving haemoglobin concentration in the population.We are uncertain whether fortification of maize flour with iron reduces anaemia among the general population, as the certainty of the evidence is very low. No studies reported on any adverse effects.Public organisations funded three of the five included studies, while the private sector gave grants to universities to perform the other two. The presence of industry funding for some of these trials did not appear to positively influence results from these studies.The reduced number of studies, including only two age groups (children and women of reproductive age), as well as the limited number of comparisons (only one out of the four planned) constitute the main limitations of this review.

Equity in access to fortified maize flour and corn meal

Mass fortification of maize flour and corn meal with a single or multiple micronutrients is a public health intervention that aims to improve vitamin and mineral intake, micronutrient nutritional status, health, and development of the general population. Micronutrient malnutrition is unevenly distributed among population groups and is importantly determined by social factors, such as living conditions, socioeconomic position, gender, cultural norms, health systems, and the socioeconomic and political context in which people access food. Efforts trying to make fortified foods accessible to the population groups that most need them require acknowledgment of the role of these determinants. Using a perspective of social determinants of health, this article presents a conceptual framework to approach equity in access to fortified maize flour and corn meal, and provides nonexhaustive examples that illustrate the different levels included in the framework. Key monitoring areas and issues to consider in order to expand and guarantee a more equitable access to maize flour and corn meal are described.

Micronutrient fortification of food and its impact on woman and child health: a systematic review

BACKGROUND

Vitamins and minerals are essential for growth and metabolism. The World Health Organization estimates that more than 2 billion people are deficient in key vitamins and minerals. Groups most vulnerable to these micronutrient deficiencies are pregnant and lactating women and young children, given their increased demands. Food fortification is one of the strategies that has been used safely and effectively to prevent vitamin and mineral deficiencies.

METHODS

A comprehensive search was done to identify all available evidence for the impact of fortification interventions. Studies were included if food was fortified with a single, dual or multiple micronutrients and impact of fortification was analyzed on the health outcomes and relevant biochemical indicators of women and children. We performed a meta-analysis of outcomes using Review Manager Software version 5.1.

RESULTS

Our systematic review identified 201 studies that we reviewed for outcomes of relevance. Fortification for children showed significant impacts on increasing serum micronutrient concentrations. Hematologic markers also improved, including hemoglobin concentrations, which showed a significant rise when food was fortified with vitamin A, iron and multiple micronutrients. Fortification with zinc had no significant adverse impact on hemoglobin levels. Multiple micronutrient fortification showed non-significant impacts on height for age, weight for age and weight for height Z-scores, although they showed positive trends. The results for fortification in women showed that calcium and vitamin D fortification had significant impacts in the post-menopausal age group. Iron fortification led to a significant increase in serum ferritin and hemoglobin levels in women of reproductive age and pregnant women. Folate fortification significantly reduced the incidence of congenital abnormalities like neural tube defects without increasing the incidence of twinning. The number of studies pooled for zinc and multiple micronutrients for women were few, though the evidence suggested benefit. There was a dearth of evidence for the impact of fortification strategies on morbidity and mortality outcomes in women and children.

CONCLUSION

Fortification is potentially an effective strategy but evidence from the developing world is scarce. Programs need to assess the direct impact of fortification on morbidity and mortality.

Effects of micronutrient fortified milk and cereal food for infants and children: a systematic review

BACKGROUND

Micronutrient deficiency is a common public health problem in developing countries, especially for infants and children in the first two years of life. As this is an important time window for child development, micronutrient fortified complementary feeding after 6 months of age, for example with milk or cereals products, in combination with continued breastfeeding, is recommended. The overall effect of this approach is unclear.

METHODS

We performed a Systematic Review and Meta-analysis to assess the impact of micronutrient fortified milk and cereal food on the health of infants and little children (aged 6 months to 5 years) compared to non-fortified food. We reviewed randomized controlled trials using electronic databases (MEDLINE and Cochrane library searches through FEB 2011), reference list screening and hand searches. Three reviewers assessed 1153 studies for eligibility and extracted data. One reviewer assessed risk of bias using predefined forms.

RESULTS

We included 18 trials in our analysis (n = 5'468 children; range of mean hemoglobin values: 9.0 to 12.6 g/dl). Iron plus multi micronutrient fortification is more effective than single iron fortification for hematologic outcomes. Compared to non-fortified food, iron multi micronutrient fortification increases hemoglobin levels by 0.87 g/dl (95%-CI: 0.57 to 1.16; 8 studies) and reduces risk of anemia by 57% (relative risk 0.43; 95%-CI 0.26 to 0.71; absolute risk reduction 22%; number needed to treat 5 [95%-CI: 4 to 6]; 6 Studies). Compared to non-fortified food, fortification increases serum levels of vitamin A but not of zinc. Information about functional health outcomes (e.g. weight gain) and morbidity was scarce and evidence is inconclusive. Risk of bias is unclear due to underreporting, but high quality studies lead to similar results in a sensitivity analysis.

CONCLUSIONS

Multi micronutrient fortified milk and cereal products can be an effective option to reduce anemia of children up to three years of age in developing countries. On the basis of our data the evidence for functional health outcomes is still inconclusive.

The use and interpretation of serum retinol distributions in evaluating the public health impact of vitamin A programmes

Objective

Developing countries have adopted universal, high-potency vitamin A (VA) supplementation and food fortification as major strategies to control deficiency, prevent nutritional blindness and reduce child mortality. Yet questions persist regarding how best to measure impact and when to phase out supplementation. The present paper provides guidance on the use and interpretation of serum retinol (SROL) distributions as indicators of both programme impact and adequate VA intake in a population.

Design

We reviewed extant data on SROL's response to high-potency VA supplementation and VA-fortified foods in children.

Results

Supplementation virtually eliminates xerophthalmia and reduces child mortality; however, it shifts the SROL distribution only transiently (<2 months). Regular consumption of VA-fortified foods prevents xerophthalmia, lowers mortality and sustainably improves SROL distributions, from which both compliance and public health impact can be inferred.

Conclusions

Given SROL's limited responsiveness to high-potency VA supplementation, target population coverage remains the preferred performance indicator. However, periodic SROL surveys do reflect underlying dietary risk and can guide programming: low or marginal SROL distributions in areas with high supplementation coverage do not signify programme failure, but rather suggest the need to continue supplementation while working to effectively raise dietary VA intakes. We propose that a sustained rise in the SROL distribution, defined as ≤5 % prevalence of SROL < 0·70 μmol/l among vulnerable population groups in at least two consecutive surveys (≥1 year apart), be used as an indicator of stable and adequate dietary VA intake and status in a population, at which point programmes may re-evaluate the need for continued universal supplementation.

Do multiple micronutrient interventions improve child health, growth, and development?

Micronutrient deficiencies are common and often co-occur in many developing countries. Several studies have examined the benefits of providing multiple micronutrient (MMN) interventions during pregnancy and childhood, but the implications for programs remain unclear. The key objective of this review is to summarize what is known about the efficacy of MMN interventions during early childhood on functional outcomes, namely, child health, survival, growth, and development, to guide policy and identify gaps for future research. We identified review articles including meta-analyses and intervention studies that evaluated the benefits of MMN interventions (3 or more micronutrients) in children (<5 y of age) using Pubmed and EMBASE. Several controlled trials (n = 45) and meta-analyses (n = 6) have evaluated the effects of MMN interventions primarily for child morbidity, anemia, and growth. Two studies found no effects on child mortality. The findings for respiratory illness and diarrhea are mixed, although suggestive of benefit when provided as fortified foods. There is evidence from several controlled trials (>25) and 2 meta-analyses that MMN interventions improve hemoglobin concentrations and reduce anemia, but the effects were small compared to providing only iron or iron with folic acid. Two recent meta-analyses and several intervention trials also indicated that MMN interventions improve linear growth compared to providing a placebo or single nutrients. Much less is known about the effects on MMN interventions during early childhood on motor and mental development. In summary, MMN interventions may result in improved outcomes for children in settings where micronutrient deficiencies are widespread.

Provision of multiple rather than two or fewer micronutrients more effectively improves growth and other outcomes in micronutrient-deficient children and adults

Deficiencies of multiple micronutrients (MMN) usually coexist in developing countries, but supplements have usually provided only 1 or 2 micronutrients (MN). To inform policy, in this article we compared the relative benefits of supplying MMN vs. a placebo or 1 or 2 MN on the following: children's growth, health, and development; pregnancy outcome; nutritional status; and HIV/AIDS mortality and morbidity in adults. Sufficient data were available to perform random-effects meta-analyses of randomized controlled trials (RCT) for the effects of MMN on child growth and nutritional status. Results for other outcomes are presented as effect sizes (ES) when available. In children, MMN interventions resulted in small but significantly greater improvements in length or height (ES = 0.13; 95% CI: 0.055, 0.21) and weight (ES = 0.14; 95% CI: 0.029, 0.25), hemoglobin (ES = 0.39; 95% CI: 0.25, 0.53), serum zinc (ES = 0.23; 95% CI: 0.18, 0.43), serum retinol (ES = 0.33; 95% CI: 0.050, 0.61), and motor development. A Cochrane review reported that compared with no supplementation or a placebo, MMN supplementation during pregnancy reduced the relative risk of low birth weight (0.83), small-for-gestational age (0.92), and anemia (0.61); however, MMN were not more effective than iron + folic acid alone. There is some evidence that MMN supplementation improves CD4 counts and HIV-related morbidity and mortality in adults. The efficacy of MMN varies across trials, but overall there is evidence that outcomes are better than when providing < or =2 MN. The policy implications of these studies are discussed.

Effects of micronutrients on growth of children under 5 y of age: meta-analyses of single and multiple nutrient interventions

BACKGROUND

Micronutrient interventions have received much attention as a cost-effective and promising strategy to improve child health, but their roles in improving child growth remain unclear.

OBJECTIVE

Meta-analyses of randomized controlled trials were conducted to evaluate the effect of micronutrient interventions on the growth of children aged <5 y old.

DESIGN

Eligible studies were identified by PubMed database searches and other methods. Weighted mean effect sizes and 95% CIs were calculated for changes in height, weight, and weight-for-height z scores (WHZ) by using random-effect models. Tests for publication bias were done by using funnel plots, heterogeneity, and stratified analyses by predefined characteristics.

RESULTS

Interventions including iron (n = 27) or vitamin A (n = 17) only had no significant effects on growth. Interventions including zinc only (n = 43) had a small positive effect (effect size = 0.06; 95% CI: 0.006, 0.11) on change in WHZ but no significant effect on height or weight gain. Multiple micronutrient interventions (n = 20) improved linear growth (0.09; 95% CI: 0.008, 0.17).

CONCLUSIONS

Our findings confirm earlier results of no benefits for interventions including iron and vitamin A only but differ from the earlier meta-analysis that found improvements in linear growth for zinc only interventions. This may be due to the improved nutritional status of children in the more recent studies. Multiple micronutrient interventions improve linear growth, but the benefits are small. Other strategies are needed to prevent stunting.

Maternal and child nutrition in Sub-Saharan Africa: challenges and interventions

Women of child-bearing age (especially pregnant and lactating women), infants and young children are in the most nutritionally-vulnerable stages of the life cycle. Maternal malnutrition is a major predisposing factor for morbidity and mortality among African women. The causes include inadequate food intake, poor nutritional quality of diets, frequent infections and short inter-pregnancy intervals. Evidence for maternal malnutrition is provided by the fact that between 5 and 20% of African women have a low BMI as a result of chronic hunger. Across the continent the prevalence of anaemia ranges from 21 to 80%, with similarly high values for both vitamin A and Zn deficiency levels. Another challenge is the high rates of HIV infection, which compromise maternal nutritional status. The consequences of poor maternal nutritional status are reflected in low pregnancy weight gain and high infant and maternal morbidity and mortality. Suboptimal infant feeding practices, poor quality of complementary foods, frequent infections and micronutrient deficiencies have largely contributed to the high mortality among infants and young children in the region. Feeding children whose mothers are infected with HIV continues to remain an issue requiring urgent attention. There are successful interventions to improve the nutrition of mothers, infants and young children, which will be addressed. Interventions to improve the nutrition of infants and young children, particularly in relation to the improvement of micronutrient intakes of young children, will be discussed. The recent release by WHO of new international growth standards for assessing the growth and nutritional status of children provides the tool for early detection of growth faltering and for appropriate intervention.

Effect of combining multiple micronutrients with iron supplementation on Hb response in children: systematic review of randomized controlled trials

OBJECTIVES

To study the effect of combining multiple (two or more) micronutrients with Fe supplementation on Hb response, when compared with placebo and with Fe supplementation, in children.

DATA SOURCES

Electronic databases, personal files, hand search of reviews, bibliographies of books, and abstracts and proceedings of international conferences.

REVIEW METHODS

Randomized controlled trials evaluating change in Hb levels with interventions that included Fe and multiple-micronutrient supplementation in comparison to placebo alone or Fe alone were analysed in two systematic reviews.

RESULTS

Twenty-five trials were included in the review comparing Fe and micronutrient supplementation with placebo. The pooled estimate (random effects model) for change in Hb with Fe and micronutrient supplementation (weighted mean difference) was 0.65 g/dl (95 % CI 0.50, 0.80, P < 0.001). Lower baseline Hb, lower height-for-age Z score, non-intake of 'other micronutrients' and malarial non-hyperendemic region were significant predictors of greater Hb response and heterogeneity. Thirteen trials were included in the review comparing Fe and micronutrient supplementation with Fe alone. The pooled estimate for change in Hb with Fe and micronutrient supplementation (weighted mean difference) was 0.14 g/dl (95 % CI 0.00, 0.28, P = 0.04). None of the variables were found to be significant predictors of Hb response.

CONCLUSIONS

Synthesized evidence indicates that addition of multiple micronutrients to Fe supplementation may only marginally improve Hb response compared with Fe supplementation alone. However, addition of 'other micronutrients' may have a negative effect. Routine addition of unselected multiple micronutrients to Fe therefore appears unjustified for nutritional anaemia control programmes.

Maize meal fortification is associated with improved vitamin A and iron status in adolescents and reduced childhood anaemia in a food aid-dependent refugee population

OBJECTIVE

To assess changes in the Fe and vitamin A status of the population of Nangweshi refugee camp associated with the introduction of maize meal fortification.

DESIGN

Pre- and post-intervention study using a longitudinal cohort.

SETTING

Nangweshi refugee camp, Zambia.

SUBJECTS

Two hundred and twelve adolescents (10-19 years), 157 children (6-59 months) and 118 women (20-49 years) were selected at random by household survey in July 2003 and followed up after 12 months.

RESULTS

Maize grain was milled and fortified in two custom-designed mills installed at a central location in the camp and a daily ration of 400 g per person was distributed twice monthly to households as part of the routine food aid ration. During the intervention period mean Hb increased in children (0.87 g/dl; P < 0.001) and adolescents (0.24 g/dl; P = 0.043) but did not increase in women. Anaemia decreased in children by 23.4% (P < 0.001) but there was no significant change in adolescents or women. Serum transferrin receptor (log10-transformed) decreased by -0.082 microg/ml (P = 0.036) indicating an improvement in the Fe status of adolescents but there was no significant decrease in the prevalence of deficiency (-8.5%; P = 0.079). In adolescents, serum retinol increased by 0.16 micromol/l (P < 0.001) and vitamin A deficiency decreased by 26.1% (P < 0.001).

CONCLUSIONS

The introduction of fortified maize meal led to a decrease in anaemia in children and a decrease in vitamin A deficiency in adolescents. Centralised, camp-level milling and fortification of maize meal is a feasible and pertinent intervention in food aid operations.

Addressing malnutrition in young children in South Africa. Setting the national context for paediatric food-based dietary guidelines

Despite various national nutrition and primary healthcare programmes being initiated in South Africa over the last decade, child health has deteriorated. This is seen by the rise in infant and child mortality rates, the high prevalence of preventable childhood diseases, e.g. diarrhoea and lower respiratory tract infections, and the coexistence of under-nutrition along with HIV/AIDS. Poor dietary intake, food insecurity and poor quality of basic services prevail within this precarious causal web. The national Integrated Nutrition Programme is a comprehensive nutrition strategy that focuses on children below 6 years old, at-risk pregnant and lactating women, and those affected by communicable and non-communicable diseases. Focus areas relevant to pre-school children include disease-specific nutrition treatment, support and counselling; growth monitoring and promotion (GMP); micronutrient malnutrition control; breastfeeding promotion, protection and support; contributions to household food security; nutrition interventions among HIV-infected children; and nutrition promotion, education and advocacy. Progress towards this includes the Baby-Friendly Hospital Initiative; mandatory fortification of maize meal and wheat flour with multiple micronutrients; vitamin A supplementation coverage and mandatory iodization of salt by legislation; the provision of free road-to-health charts for GMP; and the National School Nutrition Programme. Since 2003, the basis of the nutrition education strategy has been the locally developed food-based dietary guidelines (FBDGs), directed at adults and school-going children. This review sketches the backdrop to and motivation for the introduction of specifically targeted paediatric FBDGs, for mothers and caregivers of children from birth to age 7 years, as a national initiative.