Iodine - An Essential Nutrient For Thyroid Health

Iodine is a micromineral that helps your body produce the thyroid hormones thyroxine (T4) and triiodothyronine (T3). It is essential for thyroid health and supports a number of functions throughout the body. In this article I will be discussing this nutrient in greater detail and providing you with a summary of its main functions, the best food sources, the recommended daily allowances (RDAs) and the potentially adverse effects of consuming too much or too little.

1) DISCOVERY:

Iodine was discovered and isolated in 1811 by the French chemist Bernard Courtois. He actually made the discovery by accident when he was using sulfuric acid to make compounds of potassium and sodium from seaweed. One day he used too much sulfuric acid which caused violet vapour to rise from the mixture. This violet vapour turned out to be a new element which Courtois named iodine.

2) FUNCTION:

As I mentioned above the main role of iodine in the body is to support good thyroid health and help the body produce two major thyroid hormones; thyroxine (which regulates body heat and the use of oxygen in cells) and triiodothyronine (which affects almost every process in the human body including growth and heart rate). It also helps your body maintain a normal metabolic rate, prevents the development of simple goiter (a condition which enlarges the thyroid gland), keeps your hair, nails, skin and teeth healthy and keeps your immune system strong.

3) RDA:

The RDA for iodine increases with age. Children aged between 0 and 6 months are advised to consume 0.11 milligrams (mg) per day. This requirement increases to 0.12mg for children aged between 9 and 13 years. Adults aged 14 years and older should consume 0.15mg of this nutrient each day. The tolerable upper limit (TUL) for iodine is 1.1mg per day.

4) FOOD SOURCES:

Iodine can be found in a wide variety of foods. Eggs (0.026mg per 100g), iodised salt (3mg per 100g), oysters (0.157mg per 100g) and yogurt (0.034mg per 100g) are all excellent sources of this nutrient.

5) OVERDOSE SYMPTOMS:

Since most foods only contain small amounts of iodine it is very difficult to overdose from natural sources. However, taking too many supplements can cause an overdose for which the symptoms include burning in the mouth, diarrhea, nausea, stomach pain and vomiting.

6) DEFICIENCY SYMPTOMS:

Iodine deficiency is very rare in the UK due to the introduction of iodised salt and also because it is added to animal feed (which increases the iodine content of dairy products and meats). However, in countries where this does not happen deficiency can be a problem. The symptoms of deficiency include depression, fatigue, hyperthyroidism (a condition where your body over produces thyroid hormones), hypothyroidism (a condition where your body under produces thyroid hormones), stunted growth and poor mental development in very young children and weight gain.