Today, as a sensible consumer, you opt for "iodized table salt". Iodine, a trace mineral, is required by the body to control its rate of metabolism. It is also required for the proper functioning of the thyroid gland (located in the front of your neck, just under your voice box), which stores about 60 percent of the iodine in the body. Iodine prevents the accumulation of excess fat in the body by ensuring optimum utilization of calories.
What are the Functions of Iodine?
- Controlling the Metabolic Rates: Iodine is required by the body for the synthesis of the thyroid hormones, thyroxine (T4 - containing 4 iodone atoms) and triiodothyronine (T3 - containing 3 iodine atoms). These hormones play an important part in the controlling of the basic metabolic rate (BMR). Also, these hormones help regulate the heart rate, blood pressure, temperature and body weight.
- Maintaining the Energy Levels: Iodine aids in the proper utilization of calories and this way it ensures optimum levels of energy in the body. This mechanism also prevents the storage of excess amounts of calories as fats in the body.
- Maintaining the Health of the Reproductive System: Iodine supports the growth and the maturity of the genital organs. Pregnant women need adequate amounts of iodine to lower down the possibilities of stillbirths. Iodine is also important in preventing neurocognitive conditions like cretinism in babies. Iodine is also known for promoting abilities like speech, hearing, motion and growth in babies.
- Treating Fibrocystic Diseases Effectively: Fibrocystic breast disease is caused due to increased estrogen production and is known to most women simply as having "lumpy breasts". Iodine may decrease breast tissue sensitivity to estrogen. It has been found that patients who are treated for low thyroid hormone have decreased breast pain and breast nodules. This suggests that low thyroid hormone or iodine deficiency may be a factor in fibrocystic breast disease.
- Assisting in Programmed Cell Death: Iodine assists in the process of programmed cell death or apoptosis. This process allows the development of new organs apart from ensuring the elimination of cancer cells or diseased cells which might cause harm to the individual. In a study it was found that human lung cells (with genes spliced into them that enhance iodine uptake and utilization) implanted in mice undergo apoptosis and shrink when given iodine. Researchers believe that this anti-cancer function of iodine may well prove to be it's most important benefit apart from thyroidal influence.
What are the Sources of Iodine?
The daily recommended intake of iodine is between 110 and 130 mcg for infants up to 12 months, 90 mcg for children up to eight years, 120 mcg for children up to 13 years, 150 mcg for adults, 220 mcg for pregnant women and 290 mcg for lactating mothers. The thyroid gland needs no more than 70 mcg/day to synthesize the requisite daily amounts of thyroid hormones.
Iodine can be obtained from plant as well as animal sources. The various sources include: iodized table salt, shellfish, sardines, tuna, oyster, salmon, cod, shrimp, sea bass, kelp, and seaweed. Dairy products also contain iodine. Other good sources are plants grown in iodine-rich soil.
What are the Deficiency Symptoms of Iodine?
- Development of Goitre, or enlargement of the thyroid gland, is usually the earliest visible symptom of iodine deficiency. The enlargement of the thyroid results from overstimulation of the thyroid gland by thyroid stimulating hormone (TSH), as the body attempts to produce increased amounts of thyroid hormone. Goiter can occur for many other reasons as well, but iodine deficiency is among the most common causes worldwide.
- Iodine deficiency can lead to the malfunctioning of the thyroid gland, which in turn, can cause an abnormal gain in the body weight due to deposition of excess calories as fats.
- Iodine deficiency can also cause depression, frustration and poor levels of perception.
- Iodine deficiency raises the risk of stillbirth in pregnant women.
- Constipation and fatigue are the other conditions brought about by iodine deficiency.
- In some serious cases, mental retardation often gets associated with cretinism characterized by physical malformations.
In general, even high intakes of iodine from food are well-tolerated by most people. However, in certain circumstances, excessive consumption of iodine can actually inhibit the synthesis of thyroid hormones, thereby leading to the development of goiter (enlargement of the thyroid gland) and hypothyroidism. Excessive iodine intake may also cause hyperthyroidism, thyroid papillary cancer, and/or iodermia (a serious skin reaction). Special precautions need to be taken by expecting and lactating mothers to avoid iodine overdoses.
