Pediatric Micronutrient Pediatric Micronutrient Deficiencies, Deficiencies,

Epidemiology and Epidemiology and prevention II. prevention II.

Vitamin A and iodineVitamin A and iodine

Drora Fraser

Drora FraserDrora Fraser

Director of the S. Daniel Abraham International Center for Health and Nutrition, Ben-Gurion University of the Negev (BGU), Beer-Sheva, Israel.

Member of the Epidemiology and Health Services Evaluation Department, Faculty of Health Sciences, BGU.

Course Objectives:Course Objectives:• To familiarize the students with the extent

of the problems of micronutrient deficiencies worldwide

• To understand the implications of those problems

• Using the models of micronutrient interventions studied, learn the possible methods available and judge their applicability to their own specific situation

Prevalence of Vitamin APrevalence of Vitamin A Around the world

• 250 million children vitamin A deficient (serum retinol <0.70 mol/l)

• 3 million children have xerophthalmia (“dry eyes”)

• Areas with high rates of night blindness in children also have high rates of night blindness in mothers

Vitamin A deficiency: consequencesVitamin A deficiency: consequences

Night blindness - ancient Egypt, Greek and Assyrian medical literature

Early deaths High rates of respiratory and diarrheal

diseases Affects immunocompetence Cured with animal and fish liver or

plants with green and yellow pigments

Risk factors for VADRisk factors for VAD

Age Diet Disease Seasonality Culture Clustering

VAD statusVAD status

0 0 10 100 1000 10000 100000

Vit A

level

Vit A intake µg/kg body weight

Night blindnessXerophthalmic keratinizationDeath

DeathHepatotoxicityBone fractureHemorrhageEczema

Public Health indicatorsPublic Health indicators of of VAD and it’s importanceVAD and it’s importance

Public health importance Prevalence, percent

Indicators Mild Moderate Severe

Night blindnessat 27-71M

>0 to <1 >1 to <5 >5

Serun retinol<0.70 mol/l

>0 to <10 >10 to <20 >20

Breast milkretinol <1.05mol/l

<10 >10 to <25 >25

Ecological indicatorsEcological indicators of VADof VAD

Indicators of area and population risk

Breast feeding (BF) Prevalence %At < 6 M >50% not BF

At 7-18 M * <75% getting Vit ANutritional status $

Stunting < 3 Y >30%Wasting < 5 Y >30%LBW # <2.5 Kg >30%

Dietary pattern Vit A foods *

Illness related indicators for Illness related indicators for 6-71 month old children6-71 month old children

Indicator

Immunization <50% fully imm.

Measles casefatality rate

> 1%

Diarrhea disease (1) > 20%

Fever rates (2) > 20%

Worm infections (3) > 50%

Preferred approach to Preferred approach to prevention of VAD -1prevention of VAD -1

Preferred initial approach by importance ofthe vitamin A deficiency in the population

Severe Moderate Mild

Supplementation:Target groups + + + + +Universal ++++ + -

Fortification:Target foods +++ - -Universal - ++ ++

Preferred approach to Preferred approach to prevention of VAD-2prevention of VAD-2

Severe Mod. Mild

Food based #:Nutrition education ++ +++ ++++Food production

Food mixing+++

++++ ++ +

- -

Public health meas.Immunization ++++ ++++ ++++Parasite control ++ + -Other

Nutrition intervention programsNutrition intervention programs

Critical elements for successful programs are:

• Political commitments• Community mobilization &

participation• Human resources development• Targeting• Monitoring, evaluation &

management information systems• Replicability and sustainability

Dietary modification for VADDietary modification for VAD Ex. Where food sources of vitamin A

are underutilized:

• Thailand: VAD in preschool children, pre-clinical levels,

• Animal foods expensive

• Fruits are seasonal

• Ivy gourd-underutilized, low esteem

Dietary modification for VADDietary modification for VAD

Ex. Home and community provision of vitamin A rich foods

• Bangladesh: gardening projects-women

• High night blindness despite bi-annual supplementation programs

• Low cost gardening techniques

• Innovative resources, locally adapted

Fortification of VADFortification of VAD EX. Guatemala; sugar fortification

• Low serum retinol levels

• Low dietary intake of vitamin A

• Sugar usually refined

• Sugar consumed within a narrow range of daily intake across age groups

• In 1970, sugar was fortified with vitamin A, program very successful (Arroyave, 1979 PAHO publication)

Vitamin A supplementationVitamin A supplementation

High dose vitamin A supplementation has been used in various countries

• Need high coverage >65% of population

• Repeat delivery every 4-6 M required

• Repeat delivery difficult to maintain

• Easiest to integrate with other health care delivery

Vitamin A supplementationVitamin A supplementation High dose vitamin A supplementation

EX: Brazil

• North Eastern Brazil

• High rates of malnutrition

• Animal food sources rare & expensive

• Cultural aversion to use of green leafy vegetables

• Require: volunteers, community involvement

Cost effectiveness of VAD Cost effectiveness of VAD preventive programspreventive programs

Nutrient Place

Costa Protectb

Fortifiedsugar 1

A 0.17 0.17

Capsule2 B 0.24-0.41 0.55-0.81

Capsule2 C 0.25 0.50

Gardening andnutrition educ3.

D 2.71-4.16 na

Vitamin A deficiency - Vitamin A deficiency - summarysummary

• Vitamin A deficiency is highly prevalent

• It has severe consequences especially in the young

• Supplementation, fortification and dietary changes have all been used successfully to reduce it’s prevalence

• The cost of the programs is not high if integrated into existing child care services

Iodine deficiency (ID)Iodine deficiency (ID)

• Iodine must be obtained from the environment

• Thyroid hormones, thyroxin and triiodothyronine (T4 &T3) contain 4 and 3 iodine atoms, respectively.

• Adults need 100-150 g/daily

• Children require less in total, but more per Kg body weight

Iodine deficiency: consequencesIodine deficiency: consequences

The following are affected by iodine deficiency:

• Thyroid size; enlargement (goiter)

• Mental and neuromotor abilities

• Reproductive results

• Physical growth

Consequences of IDConsequences of ID Neuromotor and cognitive impairment

are the most important effects of ID Where ID is severe and mothers have

severe ID, endemic cretinism is found results include:

cognitive impairment learning, speech deficits psychomotor problems

Consequences of IDConsequences of ID Reproductive effects

Rates of reproduction may be lower Fetal and postnatal survival lower Motor performance in childhood impaired

Iodine correction in a group of Chinese communities doubled the neonatal survival rates

Other effects

Consequences of IDConsequences of ID Economic effects

no clear evidence available ID results in lowered energy, lowered

learning capacity, increase burden of fetal and postnatal mortality probably interfering with social development

Physical growth Hypo-thyrodism retards growth and

development

Over- correction of IDOver- correction of ID

When ID is severe and there are are thyroid nodules in ID persons, and when iodine treatment is introduced without appropriate control and monitoring, a fraction of the population will develop thyrotoxicosis.

ID prevalenceID prevalenceassessment methodsassessment methods

Goiter rates (*) Classification of goiters into grades 0, 1 and

2 ID suspected when >5% of school age

children have grade 1 or 2 goiters

Urinary iodine (**) Can define individual status Used to define population status Used to monitor interventions

Prevention of IDPrevention of ID -- fortificationfortification

• Salt fortification

– Unique in micronutrient supplementation as no dietary changes required

– Fortified product more expensive

• Social marketing to create demand

• Mass media campaigns

• Universal salt iodization is the goal

• Level of fortification 25-50 mg iodine/Kg

ID prevention-ID prevention-supplementasupplementationtion• Drops and tablets

– Original study showing that iodine prevents goiter used sodium iodide tablets given to school children twice per year

– Lugol’s solution also used in classrooms

• Iodinated oil– Iodinated poppy seed oil - New Guinea– Intra-muscular or oral routes – Well accepted– Costly due to delivery teams required

ID National ProgramsID National Programs

Ecuador• 1957-58 National survey showed

high prevalence rates of goiter and cretinism

• 1984 joint enterprise between government and Belgium government agencies started

• Local trained teams• Data collection systems

ID National ProgramsID National Programs

Nigeria• Moderate deficiency• All salt imported, 3 companies • The largest company reported

that by 1995, 97% of salt was iodized

• The company promoted the iodized salt sale

ID National ProgramsID National Programs Bolivia

• Landlocked country • 1981 survey showed goiter

prevalence of 68.1% • National program started with the

formation of a government agency in early 1980’s

• Help provided by the Italian govt.• Iodinated oil used to reach >1.4

million persons

ID National ProgramsID National Programs Europe and North America

• Iodized salt universally available

• Mass media campaign• Medical education• Nutrition education• Cooperation of industry• Iodine deficiency nearly non

existent

Iodine deficiency - summaryIodine deficiency - summary

• Iodine deficiency occurs in geographic clusters

• It results in severe mental and physical disability

• It can be virtually eliminated by national supplementation programs

• Correction of ID should be performed with close monitoring to prevent adverse reactions