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Abdullah Almarzouki, Assistant Prof. Internal Medicine Endocrinologist Umm Al Qura University Iodine deficiency 2

Iodine deficiency is a public health problem. Twenty –nine percent of the worlds population,living in approximately 130 countries,is estimated to live in areas of deficiency. 3

Approximately 5% of the world population have goiter,of these about 75% are person dwelling in areas of iodine deficiency. Such areas are found in developing countries, but also in USA and Europe. 4

Prevalent in most of the Middle East countries and a cause of thyromegaly in Sudan, Egypt, Iraq, Jordanian, Lebanon, Syria and Algeria. 5

Sources of Iodine Air, seawater, and dietary iodine. The prediction of iodine intake is difficult,if not impossible because the amount of iodine in individual foods can vary by a factor of

The minimum amount of iodine needed to prevent iodine deficiency goiter is 50µg/daily. 7

8 100 – 150 mcg/d Dietary Iodine The recommended international minimum iodine intake is 150 µg/daily. The normal recommended daily intake:

No test that can reliably diagnose iodine deficiency in individual patients is available. 9

Biochemical markers Most iodine absorbed in the body appears in the urine, so urinary iodine excretion is a good marker of very recent dietary intake. in individuals urinary iodine excretion can vary somewhat from day to day and even within a given day, but this variation tends to damp out in population. 10

Iodine nutrition at the community level is best assessed by measurements of urinary iodine, thyroid size,serum TSH and thyroglobuline. 11

Screening for iodine deficiency A timed urine collection or a 24 hours urine collection, indicates current iodine nutrition. Thyroid size and serum thyroglobulin concentration reflect iodine nutrition over a period of months or years. 12

The standard measure of iodine nutrition in community or country is the median urinary excretion,expressed in micrograms per litre. The values correspond to 70 to 80 percent of the daily iodine intake which often varies widely among people in the same community or country. 13

Iodine deficiencyNoneMildModerateSevere Median urine iodine, mcg/L>10050 – 9920 – 49<20 Goiter prevalence<5%5 – 20%20 – 30%>30% Neonatal thyroid stimulating hormone (TSH), >5 IU/mL whole blood <3%3 – 20%20 – 40%>40% Cretinism Iodine Deficiency Characteristics

Across sectional epidemiological household study in Saudi Arabia (1998) showed the presence of mild to moderate iodine deficiency with provincial differences, more severe in the South. 15

16 Saudi Arabia Total population 2008 (thousand) Annual no. births 2008 (thousand) % households consuming iodized salt Median UIE (ug/L) Proportion of population with low UIE (<100 ug/L;%) 25,

17 Total World Population billions billions billions

Clinical presentation of iodine deficiency disorders depends upon the severity, duration and timing. 18

19 Iodine deficiency disorders Endemic Goiter Hypothyroidism Cretinism Mental retardation Increased infant mortality Decreased fertility rate

Iodine deficiency during pregnancy can results in cretinism and mental retardation. 20

Early maternal iodine deficiency and during early pregnancy may cause a decrease in thyroid hormones. 21

The clinical manifestation is fetal neurological disorders 22 Spasticity Gait disturbance Deafness Mental retardation

Late maternal iodine deficiency in third trimester and after birth 23 Hypothyroidism Myxedematous baby Low IQ Short status

Iodine excretion in 24h urine 24 No deficiency > 100 µg/g Mild deficiency µg/g Moderate deficiency 20 – 49 µg/g Severe deficiency < 20 µg/g

This should be instituted based on the recommendations of the WHO. In an adult, 150 mcg/d is sufficient for normal thyroid function. Not all daily or prenatal multiple vitamins contain iodine. Replacement of iodine is most easily achieved by requesting that the patient use iodized salt in their cooking and at the table. 25 Correction of an iodine deficiency

A need to launch control program to ensure the exclusive availability of iodized salt in Saudi Arabia. A national baseline survey on the prevalence of iodine deficiency disorders is required. 26

Iodine deficiency remains the most modifiable, preventable thyroid disorder and a cause of mental retardation (brain damage). 27

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