Effects of nutritional intervention on anemia and cognitive development among pre-school children: Field experiments in India

Last registered on April 24, 2026

Pre-Trial

General Information

Title

RCT ID

AEARCTR-0018371

Initial registration date

April 19, 2026

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published

April 24, 2026, 8:47 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

Country

India

Region

Bihar

Primary Investigator

Name

Santosh Gautam

Affiliation

University of Notre Dame

Contact Primary Investigator

Other Primary Investigator(s)

PI Name

Alessandro Tarozzi

PI Affiliation

Universitat Pompeu Fabra

Contact Investigator

PI Name

Bhavya Sinha

PI Affiliation

University of Notre Dame

Contact Investigator

PI Name

Pratap Mohanty

PI Affiliation

Indian Institute of Technology, Roorkee

Contact Investigator

Additional Trial Information

Status

On going

Start date

2026-02-25

End date

2027-07-01

Keywords

Education, Health

Additional Keywords

Anemia, Micronutrient supplementation, Cognitive development, Pre-school children, Bihar, India.

JEL code(s)

12, I15, I18, I25, O12, C93

Secondary IDs

Prior work

This trial does not extend or rely on any prior RCTs.

Abstract

This study evaluates the causal impact of a preschool-based micronutrient fortification intervention on anemia and early cognitive development among children\ aged 3–5 years in rural Bihar, India. Iron-deficiency anemia remains highly prevalent in this setting and is a major constraint on early-life human capital formation. We implement a cluster-randomized controlled trial across 130 Anganwadi centers
(AWCs). The treated AWCs receive a fortified lunch intervention in which multiple micronutrient powder (MNP) is mixed into children’s daily meals for 12 months. The study follows approximately 2,600 children and collects baseline and endline data on hemoglobin concentration, anthropometric outcomes, morbidity, preschool attendance, learning outcomes, and cognitive and executive functioning. Impacts will be estimated using an intent-to-treat difference-in-differences framework with cluster-robust standard errors at the AWC level. Pre-specified heterogeneity analyses will examine differential effects by baseline anemia status, gender, household socioeconomic status, and AWC quality.

External Link(s)

Registration Citation

Citation

Gautam, Santosh et al. 2026. "Effects of nutritional intervention on anemia and cognitive development among pre-school children: Field experiments in India." AEA RCT Registry. April 24. https://doi.org/10.1257/rct.18371-1.0

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Experimental Details

Interventions

Intervention(s)

The study evaluates a school-based nutritional intervention delivered through Anganwadi Centers (AWCs) in rural Bihar, India. The intervention consists of providing multiple micronutrient powders (MNP), including iron, to preschool children aged 3–5 years. In treatment centers, trained AWC staff mix a fixed dose of MNP into a portion of the standard daily meal served to children. This supplementation is administered regularly as part of the midday feeding program over a 12-month period. AWCs are randomly assigned at the cluster (center) level into treatment and control groups. Treatment AWCs receive the MNP supplementation, while control AWCs continue with the standard government-provided meals without fortification. The intervention is implemented within existing service delivery systems, with AWC workers trained to ensure proper dosage and consumption. The intervention is complemented by baseline and endline data collection, including hemoglobin measurement (via finger-prick), anthropometric measures, and assessments of cognitive and learning outcomes.

Intervention Start Date

2026-06-01

Intervention End Date

2027-07-01

Primary Outcomes

Primary Outcomes (end points)

Hemoglobin level (Hb), Anemia, Height, Weight, Stunting, Cognitive functionings

Primary Outcomes (explanation)

These outcomes directly correspond to the main objectives of the study: reducing iron-deficiency anemia and improving early childhood cognitive development. Hemoglobin levels provide a continuous measure of iron status, while anemia prevalence captures whether children cross clinically relevant thresholds. Cognitive and executive function measures assess whether improved nutrition translates into gains in learning and developmental outcomes. All primary outcomes are measured at baseline and after 12 months of intervention exposure.

Secondary Outcomes

Secondary Outcomes (end points)

Anthropometric measures (height, weight, mid-upper arm circumference), Morbidity indicators (e.g., recent illness episodes), Household socio-economic characteristics, and food security measures

Secondary Outcomes (explanation)

These outcomes provide complementary evidence on broader health impacts and mechanisms. Anthropometric measures capture longer-term nutritional status, while morbidity indicators reflect general health improvements associated with better nutrition. Household characteristics and food security measures are used to understand contextual factors and heterogeneity in treatment effects. These outcomes are measured at baseline and endline and are not the primary focus of hypothesis testing.

Experimental Design

This study is a cluster-randomized controlled trial conducted among preschool children (ages 3–5) enrolled in Anganwadi Centers (AWCs) in rural Bihar, India. A total of 130 AWCs are randomly assigned to either a treatment group or a control group. In treatment AWCs, children receive a daily micronutrient supplementation intervention in which multiple micronutrient powder (MNP), including iron, is mixed into a portion of the standard midday meal provided at the center. Control AWCs continue to provide the standard government meal without fortification. Randomization is conducted at the AWC (center) level to minimize contamination across participants within the same center. The intervention is implemented over a 12-month period using existing service delivery systems and trained AWC staff. Data are collected at baseline and at endline (12 months later), including measures of hemoglobin, cognitive outcomes, and other child health indicators. The primary analysis follows an intent-to-treat framework comparing outcomes across treatment and control groups over time.

Experimental Design Details

Not available

Randomization Method

Randomization will be conducted in-office by the research team using a computer-based random number generator. Eligible Anganwadi Centers (AWCs) will be first listed, and each center will be assigned a random number. Centers will then be sorted based on these random numbers and assigned to treatment or control groups in equal proportion (65 treatment, 65 control). Randomization was implemented at the AWC (cluster) level prior to the start of the intervention to ensure balance across groups and to minimize contamination across participants within centers.

Randomization Unit

The unit of randomization is the Anganwadi Center (AWC). Treatment assignment is conducted at the cluster (center) level, with all eligible children within a given AWC receiving the same treatment status. There is no additional level of randomization.

Was the treatment clustered?

Yes

Experiment Characteristics

Sample size: planned number of clusters

Approximately 130-140 clusters

Sample size: planned number of observations

2000-3000 children

Sample size (or number of clusters) by treatment arms

65 treatment AWCs, 65 control AWCs

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Supporting Documents and Materials

IRB

Institutional Review Boards (IRBs)

IRB Name

University of Notre Dame

IRB Approval Date

2024-04-01

IRB Approval Number

23-08-8046

IRB Name

Institute Human Ethics Committee (IHEC), Indian Institute of Technology Roorkee

IRB Approval Date

2025-12-02

IRB Approval Number

IITR/IIC/25/68

Analysis Plan