Pediatric Micronutrient Deficiencies: Vitamin A and Iodine

1. Pediatric Micronutrient Deficiencies, Epidemiology and prevention II. Vitamin A and iodineDrora Fraser

2. Drora 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.

3. 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

4. Prevalence 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

5. Vitamin 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

6. Risk factors for VAD • Age • Diet • Disease • Seasonality • Culture • Clustering

7. VAD status Death Hepatotoxicity Bone fracture Hemorrhage Eczema Vit A level Night blindness Xerophthalmic keratinization Death Vit A intake µg/kg body weight

8. Public Health indicatorsof VAD and it’s importance

9. Ecological indicatorsof VAD

10. Illness related indicators for 6-71 month old children

11. Preferred approach to prevention of VAD -1

12. Preferred approach to prevention of VAD-2

13. Nutrition 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

14. Dietary 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

15. Dietary 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

16. Fortification 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)

17. Vitamin 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

18. Vitamin 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

19. Cost effectiveness of VAD preventive programs

20. Vitamin A deficiency - summary • 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

21. 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

22. Iodine deficiency: consequences The following are affected by iodine deficiency: • Thyroid size; enlargement (goiter) • Mental and neuromotor abilities • Reproductive results • Physical growth

23. Consequences 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

24. Consequences 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

25. Consequences 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

26. Over- 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.

27. ID prevalenceassessment 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

28. Prevention of ID-fortification • 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

29. ID prevention-supplementation • 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

30. ID 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

31. ID 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

32. ID 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

33. ID 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

34. Iodine 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