Iodine deficiency it’s control and food

fortificationDr.Rakhshinda Ambreen

MSPH

Learning Objectives:By the end of the session students will be able:

• To define iodine deficiency

• To define goitrogens

• To identify sources of iodine

• To list Epidemiological assessment of iodine deficiency

• To Name International Iodine Control Strategies

• To name Iodine Control Program of Pakistan

HOW DO PEOPLE OBTAIN MICRONUTRIENTS?

INTRODUCTION

• Iodine is an essential trace element.

• 80%of the iodine distribution in the body(15 milligrams in adult) is present in the thyroid gland where it is used in the synthesis of several thyroid hormones.

• The remainder is distributed throughout other tissues, particularly in the mammary, salivary, gastric glands and in the kidneys.

• Within the circulation iodine occurs in the form of free iodine ion or as protein-bound iodine.

• Excretion is primarily in urine and small amount in feces

Functions

it is an integral part of thyroid hormones that play a major role in regulating growth and development.

They also have important role in regulation of metabolic rate.

• it is required for early development of nervous system during fetal life.

• it is needed for normal reproductive function.

Synthesis of thyroid hormones

• thyroxine (T4)

• Triiodothyronine (T3)

IODINE DEFICIENCY:

It is the leading cause of preventable intellectual impairment.

It is associated with a variety of clinical disorders called "iodine deficiency disorders".

• IDD is known to be significant health problem in 118 countries, IDD affects 740 million of people(13% of world population),

• 30% of remainder are at risk IDD affect poor pregnant women, preschool children causing serious health problems

DEFICIENCY

• endemic cretinism

• hypothyroidism

• mental retardation

• reproductive failure, abortion & still birth

• endemic goiter

• childhood mortality

• socio-economic retardation

Hypothyroidism

• Some patients develop hypothyroidism, which could be mild (low thyroid hormone level, low BMR, low productivity, slower mental function, low physical growth) or severe (classical myxoedema).

Endemic cretinism

Iodine deficiency during pregnancy can lead to birth of cretinous child. The infant may appear normal at birth but slow to grow & development, small in size, mentally dull, retarded in reaching normal developmental milestones

mental retardation:

Cretinism may be of two types:

1. Nervous cretinism: mental deficiency, deaf, mute, ataxia, Iodine deficiency occur early in fetal life.

2. Myxoedematous cretinism: dwarfism, signs of myxoedema, marked delay in growth & sexual development, mental retardation, neurological examinations are normal, deaf mutism is absent, Iodine deficiency occur late in fetal life & post natal life. In both types neurological damage, mental retardation, dwarfism are not reversible by treatment.

Endemic goiter

Enlargement of thyroid gland, most obvious clinical manifestation of iodine deficiency caused by dietary deficiency of iodine. The minimum amount of iodine required to cover the turnover of the thyroid gland is 50 microgram/day. Below this the thyroid gland will begin to enlarge markedly at puberty particularly in girls. This enlargement is considered as a compensatory mechanism to trap more iodine. In some patients large goiter may cause pressure on the trachea & esophagus which cause difficulty in breathing, irritative cough, voice changes & some time may affect swallowing.

Reproductive failure:

• Women with severe Iodine deficiency have more

• miscarriage,

• still birth ,

• LBW and other problem of pregnancy. Iodine deficiency is considered as one of the causes of de

• creased fertility of women & secondary sterility.

childhood mortality:

mortality rate in iodine deficient children is founded to be higher. Supplementation program of iodine increase in survival rate of those children.

socio-economic retardation: Iodine deficiency affects socioeconomic development of the community in many ways:

• people who are mentally slower are harder to educate, lower in productivity;

• increase in the rate of handicapped & mentally retarded children;

• domestic animals in iodine deficient areas also suffer from Iodine deficiency & produce less meat, egg & have also more abortion.

Assessing the severity of iodine deficiency in the community

The prevalence of goiter: WHO CLASSIFICATION OF GOITER SIZE:

Grade Description

0

1 A

1 B

2

3

no goiter

thyroid lobes more than end of the thumb

thyroid enlarged, visible when the head tilted back

thyroid enlarged, visible when neck in normal position

thyroid greatly enlarged, visible from about 10m

Epidemiological criteria for assessing the severity of IDD

• based on the prevalence of goiter in school-age children. Degree of IDD, expressed as % of the total of the number of children surveyed:

Total goiter rate

• 0.0-4.9% none

• 5.0-19.9% mild

• 20.0-29.9% moderate

• ≥30% severe

Assessment of Iodine deficiency

1. Urine iodine examination of iodine concentration in urine could be done on 24-hour urine samples or on casual urine sample. Median urinary iodine concentration of ≥ 100 microgram/l define population which has no iodine deficiency. urinary iodine concentration is currently the most practical biochemical marker for iodine nutrition.

2. determining thyroid size by ultrasonography: safe, non invasive technique, provide more precise measurement of thyroid volume compared with palpation. Need ultrasound equipment, electricity & specially trained personnel.

3. laboratory tests related to thyroid hormones: levels of thyroid stimulating hormone (TSH), thymoglobulin (TG) can serve as surveillance indicators.

Iodine deficiency (Pakistan’s scenario)

Iodine Deficiency

Prevention & control of IDD

• • universal salt iodization: this greatly decreases the goiter in many countries, the amount added should be related to the usual consumption in the community (5-10 g/person/day). It is recommended that iodine concentration in the salt at site of production should be within the range of 20-40mg of iodine/kg of salt (20-40ppm of iodine) in order to provide 150 microgram of iodine/person/day.

2.administration of iodized oil either in form of injection or capsule:

• alternative mean where the use of iodized salt is not possible & when endemic goiter is more severe and accompanied by endemic cretinism. Single injection (1 ml IM) will provide protection for more than 1 year (2-4y), or we give iodized oil capsule every 6-18 months.

3.iodization of water supply:

• in remote village where distribution of iodized salt or injection of iodized oil is impractical. It reduced the prevalence of goiter in some area by about 30-61%.

• dietary modification: to include more of the food known to be good source of iodine (sea food, sea & fresh water fish).

• good medical service & health care: for early diagnosis & treatment of goiter and hypothyroidism.

• direct administration of iodine solution, such as Lugol's iodine, at regular interval (once a month).

Dietary modification

• To include more food known to be good source of iodine(sea food, sea and fresh water fish.

IODINE CONTROL PROGRAME IN PAKISTAN

• • The Iodine Deficiency Project was a joint effort between the government of Pakistan, UNICEF and Population Services International (PSI) in the early nineties. These three groups collaborated to tackle the issue which causes health problems such as goiter, cretinism, stillbirths and deaf, mutism.

• About 20 million people live in iodine-deficient areas of Pakistan. Of these, 8 million show some manifestation of iodine deficiency, and at least a million show some degree of mental retardation

IODINE CONTROL PROGRAME IN PAKISTAN

• Previous efforts to fortify oil with iodide had been met with limited success.

• The next simplest option was to fortify salt with iodine. Successful but still could not reach the rural population.

• laborers at salt processing plants with the technical abilities to iodize the salt. Instead of focusing on the harmful and negative aspects of the disease, the campaign chose to concentrate on positive images.

IODINE CONTROL PROGRAME IN PAKISTAN

“Hand & Pot” logo. The goals of the campaign were to increase iodized salt consumption to combat iodine deficiency, as well as to create demand for iodized salt through social marketing while also increasing production.

Iodine Sources

• sea weeds

• fish

• soil

• iodized salt

• Cranberries

Recommended intake

• Adult (male &female):150 microgram/day

• Pregnant women:175 microgram/day

• Lactating women:200 microgram/day

• Children:40 microgram/day

• UL (upper intake level) of 1100µg/day (toxicity)

Risk Factors of Iodine deficiency:

1. deficient intake (diet & water): in mountain areas, isolated localities depending on well or spring in which iodine content is low;

2. increased requirement: developing fetus, newborn, young child, adolescents especially in female, pregnant & lactating women;

3. intake of goitrogens: substances occur naturally in food, that act by blocking absorption, utilization of iodine. they are found in cabbage, turnips, peanut, Soya beans & cassava. These substances are inactivated by cooking. Other goitrogens include sulfonamide.

4. deficiency of enzymes needed in the metabolism of iodine.

Goitrogens

• Chemical substances which disturb iodine utilization by thyroid gland and cause the goiter.

International Iodine Control Strategies

• 1920’s Switzerland Salt Iodization

• International Council for Control of Iodine Deficiency Disorders

universal consumption of iodized salt using a multidisciplinary approach that involves all relevant partners.

• 1992 Universal Salt Iodization

• NATIONAL STRATEGY on the elimination of iodine deficiency disorders by universal iodization of salt intended for direct human use and for bread baking 2004-2012 Romania

THANK YOU!