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NATIONAL INSTITUTE OF NUTRITIONNGUYEN DUC VINH EFFECTIVENESS OF MICRONUTRIENT FOOD FORTIFICATION ON NUTRITIONAL STATUS OF PRIMARY SCHOOL CHILDREN IN NGHIA DAN DISTRICT SPECIALIZATION : N

NATIONAL INSTITUTE OF NUTRITION

NGUYEN DUC VINH

EFFECTIVENESS OF MICRONUTRIENT FOOD FORTIFICATION

ON NUTRITIONAL STATUS OF PRIMARY SCHOOL CHILDREN

IN NGHIA DAN DISTRICT

SPECIALIZATION : NUTRITION

Ph.D THESIS SUMMARY

HA NOI - 2019

THE SCIENTIFIC SUPERVISORS:

1 Prof Dr Le Thi Hop

2 Assoc Prof Dr Bui Thi Nhung

Reviewer 1:

Reviewer 2:

The thesis will be defended in Thesis Committee at Institute level

in National Institute of Nutrition, Ha Noi

BAZ BMI for age Z-score

BMI Body Mass Index

FFQ Food Frequency Questionnaire

HAZ Height for Age Z-score

MOH Ministry of Health

NIN National Institute of Nutrition

SEANUTS The South East Asian Nutrition SurveysRDA Recommended Dietary AllowanceWAZ Weight for Age Z-score

WHO World Health Organization

WHZ Weight for Height Z-score

UNICEF The United Nations Children’s Fund

Child malnutrition has been a public health problem in developing countries,especially Asia nations, including Vietnam Malnutrition problems at pre-school andschool ages include stunting, underweight and micronutrient deficiencies, which arecommon in Vietnam Over the last two decades, nutrition policies and programshave contributed significantly in the improvement of nutritional status of under 5year-old children The underweight prevalence decreased from 19.9% to 14.1%between 2008 and 2015 The period from 2008 to 2015 saw a decline in theproportion of stunting children from 32.6% to 24.6% However, the stuntingprevalence is still quite high compared to several countries in the region Stunting isclosely related to micronutrient deficiencies Results of the South East AsianNutrition Surveys (SEANUTS) investigation on Vietnamese children who hadmicronutrient deficiencies showed that: The proportion of anemia in children aged 6

to 59 months was quite high at 23% and that in primary school age was 11.8% Theprevalence of children with low iron stores (Ferritin<30 µg/L) was high at 28.8%.The percentage of vitamin A deficiency was 7.7% and nearly half of children(48.9%) had vitamin A limitation The main reason of micronutrient deficiencies istheir diet that does not meet recommended dietary requirements Some recentstudies showed that children’s diets, especially school age in rural, mountain areaswith difficult economic conditions, not only lacked of nutrients such as protein andfat but also lacked of essential vitamins and minerals

Nghia Dan district is one of indigent mountainous districts which has a highprevalence of malnutrition in Nghe An province According to statistic data in 2012,Nghe An province had underweight prevalence at 20.2% and stunting prevalence at30.8% that were higher than national figures The district consists of 24 communesand 1 town, with a very high poverty prevalence (21.6%) Using micronutrient-fortified milk for preschool and primary school children to overcome stunting andmicronutrient deficiencies is one of the optimal solutions

Assessing the effectiveness of school milk which is fortified with

micronutrients on improved child nutritional status, the research “Effectiveness of micronutrient food fortification on nutritional status of primary school children in Nghia Dan district” was conducted with 2 objectives:

1. To describe nutritional status of preschool and primary school children in 6communes of Nghia Dan district.

2. To evaluate the effectiveness of using micronutrient-fortified food toimprove nutritional status, anemia, zinc deficiency and vitamin A deficiency

of primary school children in Nghia Dan district after 5 months ofintervention

News contributions of the thesis:

The thesis provided scientific evidence on the consumption of fortified milk on effectively improved nutritional and micronutrient status ofprimary school children The thesis results assist policy makers to developmicronutrients-fortified milk standards for School Milk Program to improvechildren stature by 2020, following Decision No.1340/QĐ-TTg dated July 8, 2016

micronutrients-by the Prime Minister

Structure of thesis

The thesis has 123 pages, including: Introduction: 2 pages; Literature review:

33 pages; Method: 20 pages; Results: 31 pages; Discussions: 22 pages;Conclusions: 2 pages; Recommendations: 1 page The thesis includes 23 tables; 34figures; 1 diagram; 88 references, in which 23 are in Vietnamese and 65 are inEnglish

CHAPTER 1 LITERATURE REVIEW

1.1. Nutritional status and micronutrient deficiencies of preschool and

primary school children

1.1.1 Nutritional status of children in the world

Malnutrition, especially stunning, is still a burden of disease leading tochildren’s illness and death over the world, especially in developing countries inAfrica, South Asia and Southeast Asia, etc

1.1.2 Nutritional status of Vietnamese children

Vietnam saw a continuous, rapid, and steady decrease of underweightprevalence at 17.5% in 2010, at 15.3% in 2013 and at 13.8% 2016, an averageannual reduction of 0.6% The percentage of stunting of children under 5 years olddeclined from 59.7% in 1985 to 53.4% in 1990 and 36.5% in 2000 Besides, theperiod from 2010 to 2016 saw a continuous fall from 29.3% to 24.3% However,stunting reduction is a challenge which is more difficult than reducing underweight.Stunting situation is also still a public health problem in Vietnam Survey results of

450 children aged 7 to 8 years old at 3 primary schools in Bac Ninh province (2005)showed that the prevalence of stunting was very high about 32-40% Studyoutcomes of nutritional status in 6 provinces in 2011 illustrated the stuntingprevalence of aged 6-9 years old group and aged 9-11 years old group at 13.7% and18.2%, respectively

1.1.3 Micronutrient deficiencies in children

a. Global micronutrient deficiencies in children

It is estimated that 7.3% global burden diseases due to micronutrientdeficiencies with nearly 2 billion people having micronutrient deficiencies Almostpeople who have micronutrition deficiencies are living in the Third world countriesand lacking of many micronutrients at the same time As of UNICEF’s statistics,there were about 750 million children suffering from iron deficiency anaemia.About one-third of children under 5 years old in developing countries is vitamin Adeficient Southeast Asia, including Vietnam is the third most zinc-deficient region

in the world

b Micronutrient deficiencies in Vietnamese children

With the problem of stunting malnutrition, the percentage of children under 5years of age with micronutrient deficiencies is high Recent research results

(Nguyen Van Nhien et al 2008) on preschoolers in rural Vietnam showed that the

prevalence of zinc, selenium, magnesium and copper deficiency was very high at86.9%, 62.3%, 51.9% and 1.7%, respectively The prevalence of anemia in childrenunder 5 years old in the whole country (2008) was 34.1%, especially in the CentralHighland 45.1%, and the South East 43.4% Low serum vitamin A status is stillprevalent in rural and mountainous areas, accounting for 10.8%.

According to the survey results of National Institute of Nutrition (NIN) in2014-2015 on subjects of children under 5 years of age, the prevalence of zincdeficiency was very high: 50.9% of boys and 48.4% of girls in urban areas sufferingfrom zinc deficiency; 73.6% of boys and 69.3% of girls in rural areas suffering fromzinc deficiency; 84.1% of boys and 77.1% of girls in mountainous areas sufferingfrom zinc deficiency

Micronutrient deficiencies in primary school children is also a public healthproblem Results of SEANUTS 2011 survey in 6 provinces showed that theprevalence of deficiencies in primary school students ranged from 46-58% Lowserum vitamin D prevalence ranged from 12-19% The percentage of anemia was11.8%, low iron stores was 28.8% The proportion of vitamin A deficiency was7.7%, and vitamin A limitation was 48.9%

1.2 Vietnamese children’s diets

One of the most important causes of malnutrition of school aged children isdue to the lack of quantity and poor quality of the diet According to the results ofthe General Nutrition Survey (GNS) 2009-2010 of NIN, the iron intake of childrenaged 2-5 reached about 70% of the recommended dietary allowance (RDA), thezinc intake met 69%, iodine intake met about 35 %, zinc and vitamin A diet had abiological activity of only about 32-35% and vitamin C diet post-processingreached 65% RDA

Survey of children’s diet aged 6-11 years in 6 provinces in 2011 showed thatdietary energy intake met 76%, calcium intake in the age group of 6-9 years reached59% and in the age group of 9-11 years at 45% of RDA; iron in diet of 6-9 years oldgroup met 68% and age group 9-11 years old met 54%; The diet of vitamin A in theage group of 6-9 years met 54% and the age group of 9-11 years met 43%, thevitamin D intake of the age group of 6-9 years met only 18% and the age group of9-11 years old met 13% of RDA

Malnutrition and micronutrient deficiencies clearly affect the intellectualdevelopment, children's learning ability, working ability towards adulthood Childmalnutrition often results in very serious consequences

1.3 Solutions for malnutrition prevention and micronutrient deficiencies for children

1.3.1 Micro-nutrient supplementation for children

There have been many studies on micronutrient supplementation for children

in Vietnam In the study on supplementation of multiple micronutrients in oral form

in children from 6 to 12 months of age (Le Thi Hop et al.), the results showed that

the prevalence of stunting significantly decreased in the daily multi-nutrientsupplement group compared with the control group and the weekly multivitaminsupplement group The research on the effect of micronutrient enriched milk andnormal milk on nutritional and micronutrient status of primary school children atYen Phong, Bac Ninh also illustrated that the prevalence of stunting and wastingstatistically reduced in multi-micronutrient fortified and normal milk groups, anddid not decline in the control group The study of Truong Tuyet Mai and NguyenThi Lam (2014) on the effectiveness of a product rich in amino acids andmicronutrients on stunted children showed effective reduction in stuntingprevalence, weight and height improvement, reduction of anemia prevalence, zincdeficiency, iron deficiency in stunted children in Bac Giang

1.3.2 Improvement of school meals

The school meal program for elementary school children has been piloted inHanoi, Da Nang and Hai Phong cities and has been expanding gradually in 63provinces and cities: the initial results showed that 59% of students ate morevegetables

1.3.3 School milk program

School milk program has been implemented in many countries around theworld for many years The most successful in the region is the School Milk Program

of China and Thailand In Vietnam, these was an implementation of the School MilkProgram in Ba Ria - Vung Tau province, phase I at 82/82 communes/wards of theprovince over 5 years As a result, the malnutrition prevalence in children aged 3-5years in the province decreased from 15.6% to 12% in just 5 years

CHAPTER 2 STUDY SUBJECTS AND METHODOLOGY

2.1 Study subjects, duration and venue

2.1.1 Study subjects

* Selecting subjects for assessing nutritional status of preschool children:

Inclusion criteria: Select all children aged 36-71 months enrolling at 6

kindergartens in 6 communes in Nghia Dan district

Exclusion criteria: Children were out of the defined age and did not go to

school; their parents refused to participate in the study

* Selecting subjects for assessing nutritional status of primary school children:

Inclusion criteria: Select all children from 6-11 years old studying at primary

schools of 6 communes in Nghia Dan district

Exclusion criteria: Children were out of the age and did not go to school; their

parents refused to participate in the study

* Selecting subjects for assessing micronutrient status for an intervention school and 2 control schools:

Inclusion criteria: Select all children from 6-11 years old with -3<HAZ ≤ -1

who were studying at the primary schools of 6 communes in Nghia Dan district.Parents and families agreed to allow children to participate in the study

Exclusion criteria: Children are milk intolerant, Children with digestive

disorders when drinking milk; Children with severe anemia: Hb<70 g / L; Childrenwith birth defects; Parents refused to let children to participate in the study

2.1.2 Venue and duration of study

2.2.1 Research design: The study was conducted in 2 stages:

Stage 1: Cross-sectional study, assessing nutritional status of 951 kindergarten

children and 2,425 primary school children studying at preschools and primary

schools in 6 communes of Nghia Dan district Based on the baseline results, 910

primary school children were selected to participate in the intervention.

Stage 2: Community intervention trial (randomized controlled trial, pre-and

post-evaluation) based on the number of subjects selected for stage 1: Theintervention group consisted of 455 students who received 180 ml of milk fortifiedwith micronutrients in 5 days/week for 5 months The control group consisted of

455 students with normal diets

Figure 2.1 Research diagram 2.2.2 Sample size

2.2.2.1 Sample size for assessing nutritional status of preschool and primary school children

All kindergarten and primary school children of 12 schools participated in thestudy

6 primary schools in 6 communes

4 intervention schools,

2 control schools

Measurement of height and weight all students

910 primary school students of

6 communes

Evaluation before intervention

Evaluation after intervention

Blood test and food survey in

120 Primary school children in Nghia Long and Nghia Thang

Blood test and food survey

in 120 Primary school children in Nghia Dan

Blood test and food survey in

120 Primary school children

Blood test and food survey in

120 Primary school children

455 students of 5 communes intervened

455 students in Nghia Long and Nghia Thang

Measurement of height and weight of 910 primary school children in 6 schools

- Drink 180ml of milk/day

- Period: 5 months

- Normal diets

- Period: 5 months

2.2.2.2 Sample size for evaluating the effectiveness of using micronutrients fortified milk on the anthropometric indices of primary school children

Applying the sample size calculation for two independent groups:

Zαβ = 7.85; ES = (μ1 – μ2)/σ2

In which:

μ1 = -1.52 (average height Z-score of intervention group - after intervention)

μ2 = -1.27 (average height Z-score of control group - after intervention)

σ = 1.11658 (covariance, from 0.79 and 1.56)

The sample size for each study group was 342 students/group, anticipating30% for dropping so 455 children for each group would be recruited

2.2.2.3 Sample size for assessing the effectiveness of using micronutrients fortified milk for the improvement of anemia, zinc deficiency and vitamin A deficiency of primary school children

a Calculate the sample size for assessing zinc status:

Applying the sample size calculation for interventional trial:

2

)(

- n is the required sample size

- C = (Zα +Zβ)2, C = 7.85 with α = 0.05 and β = 0.2 (power 80%)

- Effect Size ES = (µ1-µ2)/σ

- µ1-µ2 = 0.8 µmol/L average difference of zinc concentration between 2groups after intervention of a previous study

- σ = 1.3 is Standard deviation of means

The sample size was 42 children/group

b Calculate sample size for serum Hb assessment:

Applying the sample size calculation for interventional trial:

) (

- n is the required sample size

- C= (Zα +Zβ)2, C = 7.85 with α = 0.05 and β = 0.2 (power 80%)

- Effect size ES = (µ1-µ2)/σ

- µ1-µ2 = 0.4 g/dL average difference of Hb level between 2 groups afterintervention of a previous study

- σ = 0.76 is Standard deviation of means

The sample size was 56 children/group

c Calculation of sample size for serum vitamin A changes:

Applying the sample size calculation for interventional trial:

2

) (

- n is the required sample size

- C= (Zα +Zβ)2, C = 7.85 with α = 0.05 and β = 0.2 (power 80%)

- Effect Size = (µ1-µ2)/σ

- µ1-µ2 = 0.11µg/L average difference of serum retinol level between 2groups after intervention of a previous study

- σ = 0.3 is Standard deviation of means

The sample size was 116 children/group The combination of all three

calculating the sample size results, the intervention study was 120 children/group x

2.2.3.2 Selecting samples for evaluating the effectiveness of using micronutrient fortified milk for the anthropometric indices of primary school children.

- Step 1: After screening, students’ nutritional status was analyzed.

- Step 2: Based on the results, pair the subjects by HAZ.

- Step 3: Make a list of pairs that met the criteria to participate the study.

- Step 4: Invite parents of eligible children to meet and explain the research, if

they agreed, they would sign a consent form to secure 455 pairs

2.2.3.3 Selecting samples for assessing the effectiveness of using micronutrients fortified milk for the improvement of anemia, zinc deficiency and vitamin A deficiency of primary students: Purposive sampling.

- Step 1: After screening, select all children with -3<HAZ ≤ -1 of the

intervention school and 2 control schools

- Step 2: From the list of children in 2 schools, pair by age, gender, nutritional

status (HAZ)

- Step 3: Make a list of pairs that met the criteria to participate in the study.

- Step 4: Invite parents of children who met the criteria to attend a training and

introduction workshop, if the parents agreed, they would sign a consent form tosecure 120 pairs (240 subjects)

2.2.4 Implementation of intervention

2.2.4.1 Grouping of study

- Control group: Have a normal diet.

- Intervention group: Take 180 ml of fortified milk, 5 days/week, drink for 5

months

2.2.4.2 Implementation of intervention

- Training for teachers, health workers, and people in charge of school milkprogram at schools

- Distributing and monitoring drinking milk

- Monitoring the implementation of intervention research: The mainsupervisor in the intervention process was the PhD student Besides, there was thesupport of commune health stations, Department of Health, Department ofEducation and Training, Nghe An Provincial Preventive Medicine Center, NghiaDan District and staff of NIN

* The method of data collection:

Data collection (interviews, dietary surveys, anthropometric measurementsand blood sampling were conducted twice at the time of before intervention and atthe end of the intervention)

* Methods of lab test: Blood analysis was performed at the Department of

Micronutrient, NIN

2.2.6 Result evaluation

2.2.6.1 Nutritional status evaluation

- Assess nutrition status of children aged 0-5 years old: Using reference

population and nutritional status classification according to WHO Growth Standard2006

- Assess the nutritional status of children aged 6-11 years old: Based on WHO

reference population (2007) to assess the nutritional status of children aged 6-11

2.2.6.2 Diets

The child's diet is evaluated by food consumption, nutritional values of thediet (dietary energy, diet balance, protein consumption, animal/plant protein ratioand other nutrients), and the level of dietary response according to RDA for eachage based on the Table of RDA for Vietnamese in 2012

- Vitamin A deficiency cut-off points: serum retinol<0.7 µmol / L Vitamin Alimitation when serum retinol ≥ 0.7 and<1.05 µmol/L

2.2.7 Data analysis

Data collected were cleaned, checked, entered and analyzed by WHO Anthroand SPSS 11.6 Before using statistical tests, variables were tested to bring aboutnormal distribution The statistical tests in medicine were used

- Crude intervention effectiveness ratio was calculated as:

H (%) = A-B/A x 100

In which:

H is the effectiveness (%)

A is the incidence rate at the baseline

B is the incidence rate after 5 months of intervention

- Real intervention effectiveness ratio was calculated as:

Real intervention effectiveness = H1 - H2

In which:

H1 is the effectiveness ratio of intervention group

H2 the effectiveness ratio of control group

2.2.8 Methods to control errors

Anthropometric data: using the same data collectors for each time, with asingle scale and height ruler, at the same time in the morning (7-10 am) Strictlyfollow study protocol for all investigators to avoid errors

Biochemical and hematological tests have complied with the sampling andstorage procedures and the measurements have been analyzed by standardizedmethods

At the end of the investigation, the data were entered into computer Dailyentering has helped reduce errors to the maximum Randomly select 20% of thesamples to re-enter the second time, check the difference with the first time