Your familiarity with iodine likely stems from seeing the word on salt containers. This mineral was first voluntarily added to salt in the United States in 1924, according to the 2003 book, "Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification." Several medical and public health organizations urged the fortification of salt with iodine to combat the prevalence of goiter. The body's need for this mineral, however, goes beyond just preventing this thyroid condition.
Purpose
Iodine is used throughout the body, including in the blood and muscles. Its primary function is in the thyroid gland. In fact, 70 to 80 percent of this mineral is stored in this gland. Iodine's key function is in the thyroid's hormones. The mineral becomes a vital hormone component when the gland stores circulating iodine. The thyroid's function impacts major body processes, such as reproduction and metabolism. Proper human growth and development cannot occur without normal iodine levels.
Deficiency
Low iodine levels can have substantial impacts on your body, primarily due to its essential role in thyroid function. Iodine deficiency is not as common in the United States and other developed nations because of food fortification and iodine-rich soil used to grow crops. Low levels are, however, a major concern in other places in the world that don't have access to these iodine sources. Deficiency can lead to hypothyroidism, or an underactive thyroid. This causes fatigue, dry skin and weight gain. Abnormal physical and mental development is also a serious consequence, particularly in children. In fact, this deficiency is the leading cause of brain damage in the world.
Daily Needs
The Institute of Medicine's Food and Nutrition Board sets the recommended dietary allowances for iodine and other nutrients. Children ages 1 to 8 need 90 mcg daily, whereas those ages 9 through 13 need 120 mcg. From ages 14 onward, individuals should get 150 mcg a day. The highest RDAs are reserved for pregnant and breastfeeding women, who need 220 mcg and 290 mcg, respectively. An RDA is not established for infants, but the Institute of Medicine does suggest 110 mcg for babies up to 6 months old and 130 mcg for those up to a year old. Getting too much iodine is rare, although certain medical conditions -- such as cystic fibrosis -- might make your body more sensitive to high iodine intake.
Sources
Fortified salt is used in food preparation in a variety of ways, providing a good source of iodine. Just one gram has more than half the RDA for adults, at 77 mcg. Many foods contain no iodine, but seafood can be a good source of the mineral. The Linus Pauling Institute highlights cod, shrimp, tuna and seaweed for their iodine content. Seaweed is a particularly popular source among the Japanese. Many vegetables -- such as spinach and turnip greens -- might contain iodine, but how much depends on the soil in which they grow. Dairy products and eggs are also good sources.
Member Comments