Iodine is a trace mineral that is essential for the thyroid to function properly. Iodine deficiency is the number one cause of goiters and hypothyroidism worldwide. In an attempt to reduce these conditions, the United States in the 1920s started an iodized salt program and UNICEF has been spearheading a global iodized-salt program since the 1990s — both with success.
The recommended daily allowance of iodine is 150 mcg, and pregnant and nursing women require even more: 220 mcg and 290 mcg daily, respectively. These levels help prevent hypothyroidism and goiter, as well as help curb the symptoms of iodine deficiency, including slow metabolism, fatigue and weight gain.
Most people are able to meet the daily recommendation by eating natural sources of iodine, such as dairy products, saltwater fish, shellfish, soymilk, soy sauce and seaweed. While many Americans receive the recommended level of iodine in their diets, some people, especially those on low-salt diets, have lowered the amounts of iodine that they ingest. People who trade their table salt for kosher or sea salt and eat fewer process foods are actually becoming deficient in this key additive.
We’re often asked if a multivitamin is a sufficient source of iodine or whether an iodine supplement is better to take instead. Some multivitamins contain the recommended amount of this mineral, while many do not contain it at all.
Because many multivitamins don’t include iodine, an extra supplement can be a good thing; however, some iodine supplements contain hundreds to thousands of times the recommended daily dose — they are dosed in milligrams, not micrograms. Too much iodine can cause your thyroid to flare-up, leading to palpitations and anxiety. It could even lead to heart arrhythmias and osteoporosis among other serious medical conditions.
Talk to your doctor if you are unsure of your iodine levels and individual nutrient needs.
Arielle Miller Levitan, MD, is a board-certified internal medicine physician and the cofounder of Vous Vitamin, LLC. She is the author of The Vitamin Solution: Two Doctors Clear Confusion About Vitamins and Your Health. She attended Stanford University and Northwestern University’s Feinberg School of Medicine, and has served as chief medical resident for the Northwestern University McGraw Medical Center’s Evanston Hospital Program and as a clinical instructor for its medical school. She has a special interest in women’s health and preventive medicine and currently practices general internal medicine on the North Shore of Chicago, where she teaches medical students on-site. She enjoys cooking, cardio tennis, running, being a soccer mom (sometimes) and spending time with her three kids and husband (also a doctor of internal medicine).
Romy Block, MD, is a board-certified specialist in endocrine and metabolism medicine, member of American Thyroid Association, and the cofounder of Vous Vitamin, LLC. She is the author of The Vitamin Solution: Two Doctors Clear Confusion About Vitamins and Your Health. She attended Tufts University and Tel Aviv University’s Sackler School of Medicine. She completed residency training in internal medicine at North Shore University Hospital—North Shore-LIJ and did a fellowship at New York University. She practices on the North Shore of Chicago, where she specializes in thyroid disorders and pituitary diseases. She enjoys travel, food and wine, working out with her personal trainer and spending time with her husband (a pulmonary and sleep specialist) and their three boys.