Pediatric Micronutrient Deficiencies, Epidemiology and prevention II. Vitamin A and iodine Pediatric Micronutrient Deficiencies, Epidemiology and prevention II. Vitamin A and iodine Drora Fraser

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.

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 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: consequences u Night blindness - ancient Egypt, Greek and Assyrian medical literature u Early deaths u High rates of respiratory and diarrheal diseases u Affects immunocompetence u Cured with animal and fish liver or plants with green and yellow pigments

Risk factors for VAD o Age o Diet o Disease o Seasonality o Culture o Clustering

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

Public Health indicators of VAD and it’s importance

Ecological indicatorsof VAD Ecological indicators of VAD

Illness related indicators for 6-71 month old children

Preferred approach to prevention of VAD -1

Preferred approach to prevention of VAD-2

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

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

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

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)

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

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

Cost effectiveness of VAD preventive programs

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

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  g/daily Children require less in total, but more per Kg body weight

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

Consequences of ID l Neuromotor and cognitive impairment are the most important effects of ID l Where ID is severe and mothers have severe ID, endemic cretinism is found l results include: l cognitive impairment l learning, speech deficits l psychomotor problems

Consequences of ID l Reproductive effects l Rates of reproduction may be lower l Fetal and postnatal survival lower l Motor performance in childhood impaired l Iodine correction in a group of Chinese communities doubled the neonatal survival rates l Other effects

Consequences of ID u Economic effects u no clear evidence available u ID results in lowered energy, lowered learning capacity, increase burden of fetal and postnatal mortality probably interfering with social development u Physical growth u Hypo-thyrodism retards growth and development

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.

ID prevalence assessment methods oGoiter rates (*) uClassification of goiters into grades 0, 1 and 2 u ID suspected when >5% of school age children have grade 1 or 2 goiters oUrinary iodine (**) u Can define individual status u Used to define population status u Used to monitor interventions

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 mg iodine/Kg

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

ID National Programs Ecuador 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 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 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 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 - 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