Why Iodized Salt Is Important for You and Your Thyroid

Elizabeth Pearce, MD

Does your table salt contain added iodine? If not, maybe you should switch. For almost 100 years, iodized salt has been the mainstay of iodine deficiency disorders (IDD) prevention efforts in the much of the world.

Over the past 20 years, there has been a decline in the US population's consumption of iodine owing to an emphasis on low-sodium diets, an increased reliance on processed foods, and greater use of sea or kosher salts, which predominantly don't contain iodine. This shift has led to an increase in iodine deficiency, particularly in vulnerable populations.

Iodine is needed for thyroid hormone synthesis; lack of iodine can cause adverse consequences known as IDD, such as goiter and hypothyroidism.

How much iodine is needed? The US Food and Drug Administration recommends a daily intake of 150 µg for adults and children aged 13 years or older.

With the lack of a validated biomarker for assessing individual status, recommendations for iodine intake are targeted on the basis of regional population. Median urinary iodine concentrations can be used to assess the iodine status of populations. Because of substantial day-to-day and even hour-to-hour variability of urinary iodine levels in individuals, neither spot nor 24-hour urine iodine measurements can be used to diagnose iodine deficiency in patients.