The mineral is therefore needed to control the production of energy, promote growth and development and help burn fat. The best dietary source of iodine is fish and seafood, but bread and dairy foods are the main sources in the British diet. Deficiency Iodine deficiency was once fairly widespread in England, and can still occur in certain communities. Areas such as Derbyshire have very little iodine in the soil, which means that locally grown foods are low in the nutrient. Symptoms of iodine deficiency include tiredness, physical and mental slowness, weight gains, facial puffiness and constipation.
Babies born to iodine-deficient mothers are lethargic and difficult to feed.
Left untreated they develop cretinism. People such as strict vegetarians who eat no seafood or dairy products are most at risk of iodine deficiency. Excessive intake of raw cabbage or nuts can also reduce the uptake of iodine into the thyroid gland and lead to deficiency. Supplements Multivitamin and mineral supplements may provide the RDA of iodine, and it is also is present in kelp-based supplements. Safety Large doses of iodine can be toxic, leading to tachycardia, anxiety, blurred vision and vomiting.