Effects of prenatal and postnatal maternal multiple micronutrient supplementation on child growth and morbidity in Tanzania: a double-blind, randomized-controlled trial

Systematic review on supplementation, fortification, and food-based interventions for preventing iron deficiency anemia in low- and middle-income countries

BACKGROUND AND OBJECTIVES

Prioritizing key preventive and therapeutic interventions is one of the actions to accelerate the reduction of anemia. This study aimed to examine interventions designed to prevent anemia.

METHODS AND STUDY DESIGN

A systematic search was conducted in PubMed, Web of Science, Scopus, and Cochrane Library. Analysis of publication bias was done using The Joanna-Briggs Institute critical appraisal tool. Data collected from articles included author, year of publication, setting and location of the study, study type, participant of the study, intervention and control given, main outcome, main findings, and risk of bias.

RESULTS

Three nutrition-specific interventions aimed at preventing iron deficiency anemia in low- and middle-income countries used various types and dosages of iron. While most studies showed success, some indicated a worsening trend in anemia, even with standard dosages and the same form of iron. Determining effective interventions requires consideration of factors such as other micronutrient composition, compliance rate, availability of educational intervention, and dietary backgrounds in those countries.

CONCLUSIONS

Supplementation, fortification, and food-based interventions generally lead to higher hemoglobin levels and a lower prevalence of anemia. However, it is important to consider several factors before deciding on an approach.

The effects of prenatal and postnatal high-dose vitamin B-12 supplementation on human milk vitamin B-12: a randomized, double-blind, placebo-controlled trial in Tanzania

BACKGROUND

Vitamin B-12 status in human milk (HM) has critical implications for infant growth and development. Few studies have separately evaluated the effects of prenatal and postnatal maternal high-dose vitamin B-12 supplementation on HM vitamin B-12 concentration.

OBJECTIVES

This randomized controlled trial aimed to assess the effects of prenatal and postnatal vitamin B-12 supplementation on HM vitamin B-12 at 6 wk and 7 mo postpartum.

METHODS

Pregnant women were enrolled in Dar es Salaam, Tanzania, between 2001 and 2004. From recruitment (12-27 weeks of gestation) through 6 wk postpartum, participants were randomly assigned to daily oral multiple micronutrient supplementation or placebo. From 6 wk to 18 mo postpartum, a subset of participants was randomly assigned to a postnatal supplement or placebo. The supplement included 50 μg/d of vitamin B-12 and various other vitamins. HM vitamin B-12 concentrations were analyzed at 6 wk and 7 mo postpartum for 412 participants.

RESULTS

The prevalence of HM vitamin B-12 of <310 pmol/L was 73.3% and 68.4% at 6 wk and 7 mo postpartum, respectively. Prenatal supplementation increased HM vitamin B-12 concentration (percent difference: 34.4; 95% CI: 17.0, 54.5; P < 0.001) at 6 wk; this effect was not present at 7 mo. Postnatal supplementation increased HM vitamin B-12 concentration (percent difference: 15.9; 95% CI: 1.91, 31.9; P = 0.025) at 7 mo. Effect modification between prenatal and postnatal supplementation on HM vitamin B-12 status at 7 mo was found, with the effects of prenatal and postnatal supplements more pronounced among those receiving control during the other period; the prenatal supplement had a greater effect with postnatal control, and the postnatal supplement had a greater effect with prenatal control.

CONCLUSIONS

Prenatal maternal vitamin B-12 supplementation has benefits on short-term HM status, and postnatal maternal vitamin B-12 supplementation has benefits on long-term HM status. This trial was registered at clinicaltrials.gov as NCT00197548. https://clinicaltrials.gov/ct2/show/NCT00197548.

The effect of nutrition-specific and nutrition-sensitive interventions on the double burden of malnutrition in low-income and middle-income countries: a systematic review

BACKGROUND

Low-income and middle-income countries (LMICs) experiencing nutrition transition face an increasing double burden of malnutrition (DBM). WHO has urged the identification of risks and opportunities in nutrition interventions to mitigate the DBM, but robust evidence is missing. This review summarises the effect of nutrition-specific and nutrition-sensitive interventions on undernutrition and overnutrition in LMICs.

METHODS

We searched four major databases and grey literature for publications in English, French, Portuguese, and Spanish from Jan 1, 2000, to Aug 14, 2023. Eligible studies evaluated nutrition-specific or nutrition-sensitive interventions on both undernutrition and overnutrition, employing robust study designs (individually randomised, cluster randomised, and non-randomised trials; interrupted time series; controlled before-after; and prospective cohort studies). Studies were synthesised narratively, and classified as DBM-beneficial, potentially DBM-beneficial, DBM-neutral, potentially DBM-harmful, and DBM-harmful, using vote counting. This review is registered with PROSPERO (CRD42022320131).

FINDINGS

We identified 26 studies evaluating 20 nutrition-specific (maternal and child health [MCH] and school-based programmes) and six nutrition-sensitive (conditional cash transfers and other social policies) interventions. Seven of eight MCH interventions providing food-based or nutritional supplements indicated possible DBM-harmful effects, associated with increased maternal or child overweight. Most school-based programmes and MCH interventions that target behavioural change were considered potentially DBM-beneficial. Two studies of conditional cash transfers suggested DBM-beneficial effects in children, whereas one indicated potentially harmful effects on maternal overweight. A study on a family planning service and one on an education reform revealed possible long-term harmful effects on obesity.

INTERPRETATION

There is considerable scope to repurpose existing nutrition interventions to reduce the growing burden of the DBM in LMICs. In settings undergoing rapid nutrition transition, specific policy attention is required to ensure that food-based or supplement-based MCH programmes do not unintentionally increase maternal or child overweight. Consistent reporting of undernutrition and overnutrition outcomes in all nutrition interventions is essential to expand the evidence base to identify and promote interventions maximising benefits and minimising harms on the DBM.

FUNDING

President's Scholarship (Imperial College London) and National Institute for Health and Care Research.

TRANSLATIONS

For the Portuguese, Spanish and French translations of the abstract see Supplementary Materials section.