Recently, our pals at Goop brought the oft-forgotten mineral iodine to the front of our minds. According to Gwyneth's "medical medium" and the spirits that talk to him (yep), we should all be taking iodine supplements to stave off a supposedly-inevitable thyroid disease and boost our immune systems. But we're not sold yet. (We prefer to get our health advice from, at minimum, the living.) Here's what you really need to know about iodine and why it's so essential.
As Jen Gunter, MD, explains in her utterly beautiful takedown of the Goop article, your body needs iodine in order to make the hormones that essentially control your thyroid gland. Without that process working optimally, your thyroid can become under-active (hypothyroidism). And, if left untreated, that condition causes all the bodily functions that your thyroid gland helps regulate to fall out of whack, leaving you with symptoms like fatigue, forgetfulness, constipation, and even depression. Definitely not ideal.
That's why some alternative medicine gurus suggest taking iodine supplements as a way to prevent hypothyroidism and the goiters that can come with iodine deficiency. But there's no evidence that the supplements can actually prevent or treat thyroid disease, and we have plenty of other (evidence-based) ways to treat those conditions anyway.
Just because iodine is essential doesn't mean taking more is better. True iodine deficiency is rare in the U.S. and other developed countries, partly because we started supplementing our salt with iodine in 1924. Even if you eat mostly (non-iodized) sea salt, you're likely still getting plenty of iodine from your diet because we really just don't need that much of it. "We only require trace amounts, so basically eating out even a couple of times a month gets us enough iodized salt to suffice,” endocrinologist Elena A. Christofides, MD, tells Dr. Gunter.
The real worry, then, is actually taking too much iodine. If you do have a thyroid problem, iodine supplementation can make your condition worse or even cause hypothyroidism, explains Todd B. Nippoldt, MD, at the Mayo Clinic. And if you don't really have a thyroid problem at all, taking large amounts of unnecessary iodine can irritate and inflame your thyroid and even lead to thyroid cancer. Supplements can also interact with medications you may already be taking (e.g. ACE inhibitors for high blood pressure). So definitely don't start taking iodine without checking in with your doctor first.
However, there are a few groups of people — especially those who are pregnant or breastfeeding — who may need to take iodine supplements. Still, that's always done with the supervision of a doctor. So if you think your thyroid is in need of some TLC, your first stop should be your doctor's office — not the supplement aisle.