Effect of micronutrient powder supplementation for two and four months on hemoglobin level of children 6–23 months old in a slum in Dhaka: a community based observational study
© Mahfuz et al. 2016
Received: 26 November 2015
Accepted: 23 March 2016
Published: 12 April 2016
Anemia is pervasive among children under the age of two years in Bangladesh. This study aimed to assess the effect of daily supplementation of multiple micronutrient powder (MNP) for 2 months and 4 months primarily on hemoglobin status of children aged 6–23 months living in a slum of Dhaka, Bangladesh.
It was a community-based observational study where a total of 402 children and 578 children were enrolled for 2 months and 4 months MNP supplementation respectively. Venous blood was collected at enrollment and 5 months later. Hemoglobin level was measured and morbidity episodes recorded from twice weekly home visits.
At enrollment, hemoglobin levels were 10.57 ± 1.28 g/dl and 10.78 ± 1.35 g/dl across 2 months and 4 months MNP supplementation groups respectively, compared to 10.65 ± 1.36 g/dl and 11.14 ± 1.11 g/dl at the end-line after MNP supplementation. Plasma hemoglobin increased only after 4 months supplementation in difference-in-difference analysis and this was significantly more in younger children after adjusting the confounding variables (p = 0.03). Prevalence of anemia had improved for both at 2 months (p = 0.015) and 4 months (p = 0.004) of MNP supplementation. Incidence rate ratios (IRR) for diarrhea, cough and fever were comparable across the groups during the supplementation periods and IRR for acute lower respiratory tract infection was significantly lower in 4 months supplementation group with a IRR of 0.30 (95 % CI; 0.22, 0.42).
Four months MNP supplementation was relatively more effective in improving hemoglobin level in children 6–24 months.
KeywordsAnemia Micronutrient powder Hemoglobin Children Bangladesh
Globally 270 million children under the age of 5 years are affected by anemia with highest prevalence in developing countries . Anemia is prevalent among all age groups in Bangladesh especially among 6–23 month old children (62.5 %–78.7 %) . According to World Health Organization (WHO), anemia prevalence of 40 % or more in any population is considered as a severe public health problem . The alarmingly high prevalence of anemia among children, coupled with its associated adverse health, development and economic consequences highlights the need for intensified actions to address this ongoing public health problem. Iron deficiency, as defined by specific biochemical tests, is the most common cause of anemia in most parts of the world .
In developing countries, only a small fraction of the recommended daily iron requirement comes from complementary foods, and most of the consumed iron is of plant origin which absorbs less in the body than animal source iron, which together with the lack of any additional supplementation causes a large number of children to suffer from iron deficiency [5–8]. However, in recent years, home fortification of complementary foods with multiple micronutrient powders (MNP) has been proven to be the most effective and cost-efficient strategy to reduce iron deficiency and hence combat anemia in comparison to other interventions [9–12]. Two systematic reviews have concluded that MNP is as effective as iron drops in improving hemoglobin status and reduction of anemia. MNP supplementation also had better acceptance than iron drops among children and exhibits fewer side effects [9, 10]. The latest Cochrane review on the effects and safety of home fortification of foods with MNP in children under 2 implies that the use of MNP in home fortification of food resulted in reduction of anemia by 31 % . Regarding the frequency and duration of MNP supplementation, the home fortification technical advisory group of WHO recommended that 60–180 sachets of MNP sachets should be made available to target groups (children 6–23 months) over a period of 6 months . However, data on optimum duration for MNP supplementation is still uncertain for countries like Bangladesh, particularly in slum settings.
This current analysis took the opportunity of Malnutrition-Enteric disease (MAL-ED) study , where children were provided with daily MNP supplementation in a slum setting of Dhaka city . The primary aim of this study was to evaluate the relative efficacy of MNP served for two and four months period on improving plasma hemoglobin level among 6–24 months old children. This study also investigated the morbidity episodes during the MNP supplementation period and also compared the morbidity episodes with a group of children of same age from the same community without MNP supplementation.
This observational study was performed within the ongoing study of Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health (MAL-ED). The MAL-ED study is a multi-country study focused on gaining a better understanding of the risk factors contributing to malnutrition and enteric diseases and their associated health consequences in children of developing countries . In Bangladesh, the study is being conducted among residents of an under-privileged urban community in Bauniabad slum in Mirpur, Dhaka . As per the icddr,b institutional review board approved protocol of MAL-ED study in Dhaka, MNP was provided to all study children for 2 months considering the high prevalence of childhood anemia in Bangladesh. However, interim results showed that the anemia reduction was less than it was previously anticipated. Considering the success stories of longer duration MNP supplementation in Ghana and Cambodian MNP trials [17, 18], we decided to continue to provide MNP supplementation for an additional 2 months for the rest of the children. MNP was provided in sachets, with daily allowance of one sachet per child, 6 days a week for either 2 months or 4 months to all participating children. The first child was enrolled on November 15, 2009 and the last child on December 18, 2012.
Each sachet of MNP contained: 12.5 mg iron, 5 mg zinc, 300 μg vitamin A, 150 μg folic acid, and 50 mg of vitamin C. MNP sachets were distributed among the children when they attended 6 days a week one of the four feeding outposts established for the study within the slum. The caregivers (mother, grandmother or an older sibling) were asked to feed the children MNP by sprinkling the sachet contents over their first one or two servings of offered food, during the feeding sessions at the outposts. The research staff directly observed and recorded consumption of MNP by the children.
Biological sample collection and laboratory testing
Five ml of venous blood was collected from enrolled children at enrollment and 5 months. Hemoglobin (Hb) level was tested. Hb was measured by direct cyanmethemoglobin method  at the Nutritional Biochemistry Laboratory of icddr,b.
Collection of morbidity data
Morbidity episodes of the participants during the study period were collected through active surveillance where health workers recorded all morbidity episodes by visiting each home twice a week for 5 months from enrollment.
Study participants included in analysis
All data were entered into the computer after carefully cross-checked and used double data entry method. Statistical analyses were done using STATA (Version 13.1; StataCorp, College Station, Texas, USA). Statistical significance was defined as p < 0.05. The distributions of data were checked for normality by using histogram, QQ plot and kurtosis & skewness. We compared baseline characteristics between MNP groups using Student’s t tests, Pearson chi-square tests and Mann–Whitney U test. Both parametric and nonparametric approaches were used for analyses and reported as medians and interquartile ranges, or mean and standard division.
To explore the effect of 4 months MNP supplementation (TE) on hemoglobin level, we carried out the following analysis:
Calculation of crude % enhancement in hemoglobin level
TE: [(B − A) − (D − C)]
Where, A = baseline mean value for the 4 months MNP supplementation group; B = endline mean value for the 4 months MNP supplementation group; C = baseline mean value for the 2 months MNP supplementation group; D = endline mean value for the 2 months MNP supplementation group.
[(TE/A) * 100]
Yit = β0 + β1 Time + β2 Group + δ (Time × Group) + β3 X + ε
Yit = Outcome variable of interest for individual i at time t
Time = (1) if endline and (0) if baseline
Group = (1) if 4 months MNP supplementation and (0) if 2 months MNP supplementation
δ = The effect of the 4 months MNP supplementation
X = Other covariates
ε = Error term
Anemia was defined as hemoglobin less than 11 g/dl. To compare morbidity episodes between the groups we used Incidence rate ratio (IRR) with generalized linear models with a Poisson distribution. We also compared these morbidity episodes with the similar data from MAL-ED birth cohort children of the same community who were followed since birth and not provided with MNP supplementation. This comparison group was categorized in different age groups to match with 2 months and 4 months supplementation groups and IRRs were calculated after adjusting all possible confounders and compared over a period of 4 months.
Ethics, consent and permissions
The research protocol was approved by the Research Review Committee and the Ethical Review Committee of International Centre for Diarrhoeal Disease Research, Bangladesh (protocol number: PR-2008–020). Eligible children were enrolled in the study after collecting informed written consent from their parent/guardian.
Baseline characteristics of the participating children in each supplementation group
2 month MNP (n = 439)
4 month MNP (n = 379)
14 · 11 ± 5 · 25
12 · 20 ± 5 · 24
0 · 000
Feeding history (%)
Initiation of breast feeding <1 h
415 (94 · 53)
356 (93 · 93)
Introduction of soft and semisolid food
< 3 months
45 (10 · 30)
32 (8 · 44)
279 (63 · 84)
> 7 months
26 (5 · 95)
Vitamin A in the last six month
0 · 001
Weight for height z score
−1 · 07 ± 1 · 17
−0 · 70 ± 1 · 16
Height for age z score
−1 · 74 ± 1 · 25
−1 · 58 ± 1 · 18
Weight for age z score
−1 · 70 ± 1 · 28
−1 · 38 ± 1 · 28
Mother’s age (Year)a
24 · 87 ± 5 · 41
24 · 75 ± 4 · 73
Mother’s education (%)
69 (18 · 21)
Food security status
Mild food insecurity
Moderate food insecurity
Severe food insecurity
Monthly income US$ (1 US$ = 78 BDT)
Biochemical characteristic of children
10.57 ± 1.28
10.78 ± 1.35
Change of hemoglobin level after MNP supplementation
% enhancement by 4 months MNP supplementation
2 months MNP (A)
4 months MNP (B)
2 months MNP (C)
4 months MNP (D)
Mean (95 % CI)
Mean (95 % CI)
Mean (95 % CI)
Mean (95 % CI)
10.64 (10.47, 10.80)
10.78 (10.62, 10.95)
10.46 (10.17, 10.74)
11.02 (10.87, 11.17)
0.41 (0.03, 0.79)
10.53 (10.36, 10.70)
10.78 (10.55, 11.01)
10.77 (10.56, 10.98)
11.29 (11.04, 11.53)
0.27 (–0.16, 0.70)
Comparison of incidence rate ratios (IRRs) of morbidities for 4 months between the MNP supplementation groups and children without MNP supplementation
Multiple micronutrient powder
IRR (95 % CI)
IRR (95 % CI)
IRR (95 % CI)
IRR (95 % CI)
Age 6–11 months
1.28 (1.08, 1.51)
2.22 (1.30, 3.80)
1.08 (0.97, 1.21)
1.04 (0.92, 1.17)
1.26 (1.08, 1.46)
0.94 (0.52, 1.69)
1.11 (1.01, 1.23)
1.03 (0.92, 1.15)
Age 12–17 months
1.00 (081, 1.22)
1.75 (1.15, 2.64)
1.05 (0.92, 1.19)
0.97 (0.84, 1.12)
0.94 (0.76, 1.17)
0.62 (0.35, 1.09)
0.98 (0.85, 1.11)
0.95 (0.81, 1.10)
Age 18–24 months
0.81 (0.61, 1.01)
4.20 (2.32, 7.62)
0.92 (0.80, 1.07)
0.87 (0.75, 1.01)
0.83 (0.65, 1.07)
0.76 (0.28, 2.08)
0.83 (0.70, 0.98)
0.70 (0.58, 0.84)
This study examined the effect of daily dosage of 2 months and 4 months of multiple micronutrient powder supplementations on hemoglobin status of children 6–23 months in a slum of Dhaka. The results of this study had clearly shown the relative improvement of hemoglobin level in the 4 months group but not in the 2 months group, but significant reduction in prevalence of anemia in both MNP supplementation groups.
There are limited numbers of published studies that assessed the effect of MNP on anemia beyond 2 months of daily supplementation . The reduction in the prevalence of anemia in this study is in concordance with a recently completed study which compared 2 months of daily MNP supplementation with 3 months and 4 months of flexible MNP supplementation in children under the age of 24 months from Bangladesh  and observed significant reduction in the prevalence of anemia across all three intervention groups when compared to baseline prevalence. In a cluster randomized study at rural Nepal observed a significant improvement of hemoglobin status after providing MNP to children 6–9 months old over a period of 11 months in flexible doses . Moreover, in a community-based randomized trial in Ghana, significant effect on reduction of anemia prevalence was observed from daily dosage of MNP for 6 months among children from 6 to 12 months of age . The anemia prevalence decreased from 30 % at 6 months to 18 % at 12 months which is consistent with the current study. In another study, Giovannini et al. assessed the effectiveness of daily MNP supplementation on anemia and iron deficiency status in Cambodian infants over a period of one year . At the end of the study period, MNP was found to be comparable to iron drop in preventing and treating anemia as well as stabilizing plasma ferritin level. The Cochrane review also found significant reduction of anemia after both 2 months and more than 2 months of MNP supplementation and the risk reduction was higher after longer duration of MNP supplementation (44 % vs 31 %) . In multivariate analysis, when we stratified the children in two age groups as 6–11 months and 12–23 months; after adjustment of the confounders, we observed that 4 months supplementation worked better than 2 months in younger children. There has been paucity of evidence to support this finding . In Haiti, Menon et al. 2007 observed the similar phenomena. They provided MNP supplementation to 6–24 months age children for 2 months and observed that older children did not benefit from MNP to the same degree as younger children did . It could be due to the fact that older children had low iron requirement and more consumption of phytate containing cereals that reduced iron absorption .
Finally, it should be noted that the relationship between increased infection and iron supplementation is ambiguous and debatable . During infection, micro-organisms require iron for their proliferation . On the other hand, iron is essential for host immunity which combats infection . A systematic review of 28 randomized controlled studies showed no obvious harmful effect on the overall incidence of infectious illnesses in children after iron supplementation . In this study we observed significantly fewer episodes of infectious morbidity in children with 4 months MNP supplementation when compared to 2 months MNP supplementation. This finding is in contrast to a study conducted in Zanzibar  and Pakistan  where they found significantly increased number of morbidity episodes after MNP consumption. However, it should be noted that the Zanzibar study did not find any significant adverse events associated with MNP consumption in the 6–11 months group and in the Pakistan trial, incidence of febrile illness or admission to hospital for diarrhea and respiratory problems did not differ between the MNP and control groups. When we compared the IRR of morbidity with the comparison group (MAL-ED cohort), the result was mixed and inconclusive. For younger children (6-11months), comparison group was better and 4 months supplementation group was middle in terms of fewer numbers of episodes. Morbidity episodes were similar for 12–17 months children across all three comparators. And for older children (18–24 months), 4 months MNP group was better, comparison MAL-ED cohort was middle and 2 months MNP group was worse. Relatively fewer episodes of morbidity among the comparison children at younger age could be explained by the fact that the MAL-ED children were recruited as healthy newborns, so better immunity, hence fewer chances of infectious morbidities . Moreover, continuous interaction with the mothers and the research staff from the rigorous data collection in MAL-ED cohort study might responsible for “Hawthrone effect” resulted in reduced morbidity episodes [16, 21].
There are several limitations in this study. The study was not a randomized controlled trial because the original study was not designed to assess the efficacy of MNP supplementation at different duration. Moreover, the duration between the baseline and endline blood collection for the supplementation groups were also different.
Prevalence of anemia improved after both 2 months and 4 months MNP supplementation. However, 4 months MNP supplementation was more effective in improving hemoglobin status. Additionally, no additional infectious morbidities were observed after 4 months supplementation. In areas with high burden of anemia, MNP supplementation for a period for 4 months would most likely be beneficial to combat the existing high prevalence of childhood anemia.
Availability of data
Due to restriction in icddr,b’s data access policy in regard to participants identifying information, data are available upon request from the Research & Clinical Administration and Strategy (RCAS) of icddr,b (http://www.icddrb.org/component/content/article/10003-data-policies/1893-data-policies) for researchers who meet the criteria for access to confidential data.
acute lower respiratory tract infection
International Centre for Diarrhoeal Disease Research, Bangladesh
incidence rate ratios
study of Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health
multiple micronutrient powder
World Health Organization
icddr,b acknowledges with gratitude the commitment of UVA, FNIH, FIC and BMGF to its research efforts. icddr,b also gratefully acknowledges the following donors which provide unrestricted support: Government of the People’s Republic of Bangladesh, the Department of Foreign Affairs, Trade and Development (DFATD), Canada; Swedish International Development Cooperation Agency (Sida) and the Department for International Development, (UKAid).
This research protocol is funded by University of Virginia (UVA) with support from MAL-ED Network Investigators in the Foundation of National Institute of Health (FNIH), Fogarty International Centre (FIC) with overall support from the Bill & Melinda Gates Foundation (BMGF).
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
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