290 likes | 430 Views
Role of Zinc and Vitamin A in Child Health. Emorn Wasantwisut Institute of Nutrition Mahidol University. Millennium Development Goals. Eradicate extreme poverty and hunger Achieve universal primary education Promote gender equality and empower women Reduce child mortality.
E N D
Role of Zinc and Vitamin A in Child Health Emorn Wasantwisut Institute of Nutrition Mahidol University
Millennium Development Goals Eradicate extreme poverty and hunger Achieve universal primary education Promote gender equality and empower women Reduce child mortality Improve maternal health (75% of MMR by 2015) Combat HIV/AIDS, malaria, and other diseases Ensure environmental sustainability Develop a global partnership for development 1 5 6 2 7 3 4 8 Millennium Summit, Sep.2000
Selected major risks to health : Childhood and maternal undernutrition Risk factor Measured adverse outcomes (of exposure) Underweight Mortality and acute morbidity from infectious diarrhoea, malaria, measles, pneumonia and other infectious diseases. Perinatal conditions from maternal underweight Iron deficiency Anaemia, maternal and perinatal causes of death Vitamin A deficiency Diarrhoea, malaria, maternal mortality, vitamin A deficiency disease Zinc deficiency Diarrhoea, pneumonia, malaria Source : World Health Report 2002
Summary of selected risk factors • Risk Factor South - East Asia West-Pacific • Child/Adult Mortality Low High Very Low Low • Under weight 26 46 4 16 • (%< 2 SD W/A) • Iron def 11.0 10.4 12.5 11.0 • (Mean Hb in g/dl) • Vitamin A def. 28 18 0 9 • (% VAD+NB) • Zinc def. 34 73 4 9 • (% inadequate intake) World Health Rep:2002
Leading 10 selected risk factors as percentage causes of disease burden measured in DALYs Developing countries High mortality countries Under weight 14.9% Unsafe sex 10.2% Unsafe water, sanitation and hygiene 5.5% Indoor smoke from solid fuels 3.7% Zinc deficiency 3.2% Iron deficiency 3.1% Vitamin A deficiency 3.0% Blood pressure 2.5% Tobacco 2.0% Cholesterol 1.9% World Health Rep:2002
Burden of Disease - Loss of healthy life years DALYS (million) Underweight138 Iodine Deficiency 2.5 Iron Deficiency 35 Vitamin A Deficiency 22.5 Zinc Deficiency 28
Vitamin A Deficiency • Xerophthalmia blindness • limit growth • Weaken host defenses • infection & risk of death • morbidity & mortality during pregnancy and early post partum • disadvantaged newborn Childhood Women of Reproductive age
Vitamin A Supplementation Prevention Treatment at Diagnosis Age Dosage Frequency < 6 mo 50,000 IU 6, 10,14 wks with DPT/Polio < 6-11 100,000 IU Every 4-6 mo > 1 yr 200,000 IU Every 4-6 mo Women 200,000 IU < 8 wks after (? 400,000 IU) delivery Refs : WHO/UNICEF/IVACG 1997, IVACG 2000
Impact of Vitamin A on child Mortality % Reduction • Indonesia • Aceh 34 • Bogor 45 • Nepal • Sarlahi 30 • Jumla 29 • India • Tamil Nadu (wkly dose) 54 • Hyderabad 6 • Sudan+6 • Ghana19 Source : Sommer & West 1996
Global Prevalence - Maternal VAD (In millions) Serum VA BM-VA Night- <0.70 umol/L <1.05 umol/L Blindness Africa 2.4 5.4 1.1 E. Mediterranean 1.8 3.8 0.5 S/SE Asia 2.2 8.8 3.9 W.Pacific 1.2 2.7 0.5 Americas 0.4 0.8 0.4 Ref: K. West, J Nutr 2002; 132: 2857S-2866S
VA and mortality related to pregnancy 12 wks Post partum Placebo VA -carotene VA or - C b b # Pregnancies 7,241 7,747 7,201 14,948 # Deaths 51 33 26 59 Mortality 704 426 361 395 (per 100,000 pregnancies) RR 1.0 0.60 0.51 0.56 (95%CI) (0.37-0.97) (0.30-0.86) (0.37-0.84) Refs : West et al 1999
Clinical signs of severe zinc deficiency • Reduced appetite, taste acuity • Reduced growth velocity • Skin lesions • Diarrhea, other infections • Delayed sexual maturation, reduced fertility
Mean (± SD) daily per capita absorbable zinc as percent of requirement, and estimated percent of population at risk of low intake, by region
Prevalence of growth stunting • Percentage of pre-school children with height-for-age < -2 SD with respect to international reference data (data already available for most countries) • Based on prior observations that stunted (but not non-stunted) children respond to zinc supplementation with increased linear growth
Mean + 95% C.I. for effect size of change in height, by mean initial height-for-age z-score Data from Brown KH et al, AJCN, 2002
Risk of zinc deficiency, based on absorbable zinc in food supply and prevalence of growth-stunting Low Inter-mediate High
Preventive Effect of Zinc Supplementation on Diarrheal Prevalence in Continuous Supplementation Trials B.Faso India Mexico PNG Peru Vietnam Ethiopia Guatemala Jamaica Pooled 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 Odds Ratio and 95% CI
Effect of Zinc Supplementation on Duration of Acute Diarrhoea/Time to Recovery *India, 1988 *Bangladesh, 1999 *India, 2000 *Brazil, 2000 *India, 2001 Indonesia, 1998 India, 1995 Bangladesh, 1997 India, 2001 India, 2001 Nepal, 2001 Bangladesh, 2001 Pooled 1 *Difference in mean and 95% CI Relative Hazards and 95% CI
Efficacy of Zinc in Therapy of Severe Pneumonia* • Bangladeshi children <2y old with severe pneumonia • 270 randomized to 20mg zinc/d or placebo along with standard antibiotics (amp./gent.) • Zinc group had shorter duration of severe pneumonia (RH 0.81; 0.67, 0.99) and of chest indrawing, elevated RR and hypoxia * Brooks et al, submitted
Effect of Zinc Supplementation on Malaria in Children Location Reduction in Clinic Visits for Malaria The Gambia 32% (p=0.09) Papua New Guinea 38% (p<0.05) Combined 36% (CI 9-55%, p<0.05)
Trial of Zinc or Vitamin/Iron Supplementation in SGA Infants on Mortality
Prevention Effective Child Survival Interventions Cause of Under 5 death Diarrhea Pneumonia Measles Malaria.. • Exc.BF 6 mo • & Cont.BF 6-11 mo • Comp. feeding ……… • Zinc ? ? ? • Vitamin A Source : Jones et al. Lancet 2003
Treatment Effective Child Survival Interventions Cause of Under 5 death Diarrhea Pneumonia Measles Malaria.. • Oral Dehydration • Antibiotic-Pneumonia • Antimalarials ……… • Zinc • Vitamin A Source : Jones et al. Lancet 2003
Maternal IDD • stillbirth • mild to severe brain damage • fetal damage: subcretins, • neurological cretinism • Childhood and adult hypothyroidism • Neonatal Hypothyroidism: • high TSH in neonates • Cerebral hypothyroidism • Mental torpor and apathy
Iron and its effects Infants Cognition, growth& development Children Cognition/physical Adolescent Cognition/Fe store/ physical Non-pregnant Productivity Iron store Pregnant Pregnancy outcome Lactate Lactation newborns Immunity
SUPPLEMENTATION WHEN ? • 1. Treat Severe or Clinical Deficiencies • 2. Prevention in • endemic areas • high risk groups 3. NOT possible to meet requirements from diet, e.g., pregnancy, lactation
KEY TO CHANGES Form, Dose, Safety Bioavailability, Interaction, SUPPLEMENTATION Delivering System & Compliance Impact on Status Choice of food vehicles & fortification Processing, sensory, shelf-life QA system FORTIFICATION Bioavailability Impact on Status UPSCALE INTERVENTION
Baby - LBW/Undernutrition Child growth failure Early pregnancy Low Wt & Ht teenagers Small adult women Small adult men
Urine I TSH Hb/Hct TfR Bmilk-VA Dark Adapt. Retinol Urine I BLOOD SPOT (Hb/Hct TfR, Retinol) Hct TGR Urine I Monitoring & surveillance: groups & indicators Repro- ductive age women Pre- school age Mothers (P+L) & fetus Neonate & infants (0-2 yr.) School age Adults “Iodized salt” Quality of I- salt Iodine Preventive supplem. & Fd based Food Industry Iron weekly daily weekly weekly Fortified food Food based Periodic vitamin A capsule Vit A Indigenous foods