Iodine is an essential nutrient the body requires to make thyroid hormone. Insufficient iodine intake can result in thyroid diseases and abnormalities in babies born to iodine-deficient mothers. Iodine is present in some prenatal and multivitamin supplements. Children and adults, especially pregnant and nursing women, may need to supplement with iodine if they don't consume sufficient amounts of iodine from dietary sources.
Background
Potassium iodide and sodium iodide are two forms of iodine present in multivitamin supplements. According to the National Institutes of Health Office of Dietary Supplements, potassium iodide is efficiently absorbed in the human body at about 96.4 percent. Iodine supplements containing seaweed, a natural source of iodine, also are available. Not all multivitamin or prenatal supplements contain iodine; the Office of Dietary Supplements notes that in the United States, only about 51 percent of prenatal vitamins available contain iodine.
Iodine in Salt
Some brands of table salt are fortified with iodine to help prevent iodine deficiencies. Salt that contains iodine is called iodized salt, and is available in many countries, including the United States and Canada. In Canada salt is required to be iodized and in the United States, salt iodization is optional. People who consume a teaspoon of iodized table salt on a daily basis likely do not need to take iodine supplements. According to the American Thyroid Association, a teaspoon of iodized salt contains about 400 mcg of iodine.
RDAs
The Food and Nutrition Board provides Recommended Dietary Allowances, or RDAs, to determine healthy and safe amounts for certain vitamin and mineral consumption. According to the Office of Dietary Supplements, iodine RDAs are 150 mcg per day for adults, 220 mcg per day for pregnant women and 290 mcg per day for women who are breastfeeding. The American Thyroid Association urges all Canadian and American pregnant and breastfeeding women to consume prenatal vitamins that contain 150 mcg of iodine.
ULs
Tolerable Upper Intake Levels, or ULs, also are established by the Food and Nutrition Board to help determine the maximum safe amount for vitamin and mineral supplements. The UL for iodine is 1,100 mcg for all adults, including pregnant and breastfeeding women. For pregnant and breastfeeding women, ages 14 to 18, the iodine UL is 900 mcg per day.
Concerns
Excessive iodine intake can be harmful and causes problems, such as thyroid diseases. Iodine supplements may interact with certain thyroid medications, ACE inhibitors and some diuretics. Iodine supplementation should be used with caution for people who consume enough iodine through dietary sources or iodized salt. Although iodine is important during pregnancy and lactation, the Office of Dietary Supplements notes that more research is needed to determine the effects of iodine supplementation during pregnancy.
Member Comments