Pediatric Micronutrient Deficiencies, Epidemiology and prevention II. Vitamin A and iodine Pediatric...
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Transcript of Pediatric Micronutrient Deficiencies, Epidemiology and prevention II. Vitamin A and iodine Pediatric...
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