What does it do?
Iodine is needed to make thyroid hormones, which are necessary for
maintaining normal metabolism in all cells of the body. Reports suggest
that iodine may have a number of important functions in the body unrelated
to thyroid function that might help people with a wide variety of
these other uses for iodine are only supported by minimal
Where is it found?
Seafood, iodized salt, and sea vegetables—for example, kelp—are
high in iodine. Processed food may contain added iodized salt. Iodine is
frequently found in dairy products. Vegetables grown in iodine-rich soil
also contain this mineral.
likely to be deficient? People who avoid dairy, seafood, processed
food, and iodized salt can become deficient. Iodine deficiency can cause
low thyroid function, goiter, and cretinism; however, iodine deficiencies
are now uncommon in Western societies.
How much is usually
taken? Since the introduction of iodized salt, iodine supplements are
unnecessary and not recommended for most people. For strict vegetarians
who avoid salt and sea vegetables, 150 mcg per day is more than adequate.
Are there any side effects or interactions? High doses
(several milligrams per day) can interfere with normal thyroid function
and should not be taken without consulting a nutritionally oriented
The average diet provides about four times the recommended amount of
iodine, which may result in health problems.3 In fact, goiter, traditionally a
disease of iodine deficiency, is now linked sometimes to high iodine
Also, speculations of an iodine link to thyroid cancer have been
Some people react to supplemental iodine, the first symptom of which is
usually an acnelike rash.