Iodine is a trace mineral. This means that while it is an important component of many bodily functions, large quantities are not needed to achieve these crucial effects. In fact, iodine is thought to be such an important mineral that the US government came up with an ingenious way to ensure Americans get an adequate supply: Legislation recommending that iodine be added into table salt was passed. The first iodized salt was sold in the U.S. in the 1920's.
As the trace mineral iodine is ingested, 75% of it makes its way to the thyroid gland.
Once there, iodine joins up with two important hormones that are produced by the thyroid gland: triiodothyronine and thyroxine. Every part of the body requires these hormones. Most importantly, they play a role in the body's ability to produce energy. These hormones control and regulate basal metabolic rates. In other words, they determine how fast and how efficiently the body is able to burn calories.
Thyroid hormones, produced by a healthy thyroid are also what helps control a child's mental development and overall growth rate. Pregnant women who do not get enough iodine increase the risk that their newborn babies will develop some degree of mental retardation.
If you ever had a scratch or cut, as a child, it's likely that your parents put iodine on it. That's because iodine is an effective antiseptic. In addition to helping clean and heal wounds, it will discolor the skin.
At times when secretions build up in the lungs, iodine is used to thin them, making these secretions much easier to expel.
Unfortunately, individuals with iodine sensitivity may experience skin problems such as a rash or ulcers of the mucous membrane. They also may develop a fever and neck swelling.
Sources of Iodine
These days, iodine is added to some brands of table salt, so, people generally get the required amount from just one teaspoon of iodized salt. Iodine is also widely present in seafood, and sea plants, such as kelp and seaweed. Fruits and vegetables grown in coastal regions are other good sources of iodine. Processed foods are not a good source of iodine as they typically are not made with iodized salt.
The recommended daily allowance of iodine for adults is 150 mg/day. Women who are pregnant or who are breast feeding require more: 157 mg/day and 200 mg/day respectively.
Symptoms of Iodine Deficiency
Since iodine plays a role in producing energy, the most notable symptoms of a deficiency include lethargy, slowed reflexes and a slowed metabolic rate. Skin can become dry and hoarseness can develop in the throat. The amount of fat in the blood supply can increase which is why obesity is one of the symptoms of an iodine deficiency.
If an iodine deficiency continues for a long time, the thyroid gland can become enlarged. An enlarged thyroid gland is called a goiter. A goiter develops when the thyroid gland is forced to work extra hard to produce adequate levels of thyroxine. Goiters usually protrude from the side of the neck. In children, a deficiency of iodine may cause mental retardation. In fact, not getting adequate iodine is believed to be the leading preventable sources of mental retardation.
Despite the dire potential consequences of iodine deficiency, it is fortunate that this type of deficiency is rare in developed countries.
While iodine deficiency is rare, due primarily to the wide use of iodized salt, it is still also often provided in almost every daily multivitamin supplement, often at an amount equal to 100% of the daily requirement.