Urinary Iodine Analysis - Overview

• Iodine is an element required for the production of thyroid hormone. The body does not make iodine, so it is essential to derive this mineral from dietary sources. Iodine is found in some soils (insufficient in most Australian soils) and seawater. A deficiency of iodine can lead to underproduction of the thyroid hormone (thyroxine), which can result in enlargement of the thyroid (goitre), hypothyroidism and to mental retardation in infants and children whose mothers were iodine deficient during pregnancy.
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  In a normally functioning body, the thyroid makes just the right amounts of the hormones, T4 and T3, which have important actions throughout the body. These hormones regulate many aspects of our metabolism, determining how many calories we burn, our body temperature (heat and cold tolerance), and our weight. In other words, our thyroid gland controls our metabolism.
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  Hyperthyroidism – overproduction of hormones T4 and T3 acting on the cardiac and nervous systems, often presenting as palpitations and tremors caused by excess of these hormones.
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  Hypothyroidism – underproduction of hormones T4 and T4. The thyroid gland is underactive and fails to secrete sufficient hormones into the bloodstream, which causes the metabolism to slow. The early symptoms may include: weight gain, joint or muscle pain, thin brittle hair or fingernails, fatigue, depression and a greater sensitivity to cold.
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  Goitre – enlargement of the thyroid gland, which can range from a small lump to a large mass. The goitre may, if large enough, press on the oesophagus, causing difficulty swallowing and breathing as it presses on the trachea. A goitre can be the result of either hyperthyroidism or hypothyroidism.
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  Pregnancy-related problems – thyroid hormone production increases significantly during pregnancy, requiring a greater intake of iodine. Risks to the foetus are: spontaneous abortion, stillbirth, congenital abnormalities or perinatal mortality. Infants and children may suffer from impaired mental function, hypothyroidism, or delayed physical development.
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  Urinary Iodine Testing is used to assess the urinary iodine concentration in the urine. 90% of dietary iodine is eventually released into the urine.

MEDIAN URINARY IODINE CONCENTRATION (µg/L)	RELATIVE IODINE NUTRITION
< 20	Major deficiency
20-49	Moderate deficiency
50-99	Mild deficiency
100-199	Optimal
200-299	More than adequate
>299	Possible excess

Test Procedure

• First void of the day – early morning only
• To be collected Monday to Wednesday (major centres) or Monday to Tuesday (regional areas) to ensure testing within 72 hour timeframe
Discontinue all supplements and foods containing iodine 72 hours prior to sample collection
• Water only to be consumed after 9pm on the night prior to sample collection

Test Kit

• On application, a test kit will be forwarded to you from Safe Analytical Laboratories. The kit contains:
• Collection beaker
• Sample container
• Sealable plastic bag
• Disposable hand towel
• Overnight return satchel
• Client request form