Essential Iodine
Iodine is a trace mineral and an essential nutrient found in seafood, iodized salt and some vegetables. Iodine is important for hormonal development in the human body, and needed for the normal metabolism of cells. Inadequate intake of dietary iodine can lead to an enlarged thyroid gland or other iodine deficiency disorders. Iodine deficiency is the world’s leading cause of mental retardation in children.
Food sources of iodine
Iodized salt is the primary food source of iodine. Seafood is naturally rich in iodine. Cod, sea bass, haddock, and perch are excellent sources, and the common sea vegetable, Kelp, is a rich source of iodine. Most dairy products also contain iodine. Other good sources are vegetables grown in iodine-rich soil.
Iodine deficiency
The thyroid hormones regulate the body’s metabolic rate and promote growth and development throughout the body, including the brain. If there isn’t enough thyroid hormone circulating in the blood stream, the brain sends a chemical message to the thyroid gland, which then releases a measured dose of thyroid hormones. If a person’s diet is too low in iodine, the brain sends repeated chemical messages to the thyroid, which attempts to make more thyroid hormone, and the gland grows larger and larger. This abnormal enlargement of the thyroid gland is called a goiter. Other symptoms of iodine deficiency may include dry skin, hair loss, fatigue and slowed reflexes.
Cretinism
Deficiency occurs more often in women than in men, and is more common in pregnant women. Chronic lack of iodine in the diet may lead to a physical and mental aberration called cretinism. Cretinism results from inadequate secretion of thyroid hormones during fetal life or early infancy. The brain and skeleton fail to develop properly, resulting in mental retardation and dwarfism. Cretinism is rare in the U.S. because iodine deficiency is generally not a problem. Lack of iodine is a major problem, however, in developing countries and is considered to be the world’s number one cause of preventable intellectual disability in children.
Vegetarians at risk
Vegetarians may also be at risk of iodine deficiency if they do not eat seafood. Ideally, they can get their iodine from iodized table salt or seaweed. But a study published in Sep-Oct 2003 Annals of Nutrition and Metabolism showed that 25% of the vegetarians, 80% of the vegans and 9% of those eating a mixed diet had low iodine status, so there is cause for concern.
References
Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. National Academy Press, Washington, DC, 2001.
© 2011, Self Health Resource Center (SHRC) and www.DrClarkStore.com