The Potentially Dangerous Supplements That Could Lead To Thyroid Issues, According To Doctors: Calcium, More

1. Iodine

Iodine is a trace mineral that’s important for healthy thyroid function, which regulates metabolism, energy levels, and even skin health. In areas where iodine deficiency is common, or for people who don’t get enough iodine in their diets from foods like seafood and dairy, supplements can help prevent thyroid disorders such as hypothyroidism. Ensuring you get enough iodine supports hormonal balance and cognitive function—but you know what they say about too much of a good thing.

Too much iodine can backfire. Excessive iodine intake can disrupt thyroid function, potentially triggering hyperthyroidism or autoimmune thyroid conditions. These hormonal imbalances may lead to symptoms such as weight changes, fatigue, and sometimes, premature aging of the skin. The safe range for iodine is pretty narrow, so it's best to consult with a doctor before adding iodine supplements to your routine.

2. Calcium (when taken with certain medications)

Calcium is an incredibly important mineral that all of our bodies need to function. It keeps our bones, teeth, and muscles strong, and assists our nerve functions. However, before you supplement it, you should double-check with your doctor if that's a safe idea. As it turns out, calcium can cause potentially dangerous reactions when combined with some medications.

"Calcium, when taken too close to certain prescription medications, particularly iron supplements, thyroid hormones like levothyroxine, and some antibiotics, can interfere with how your body absorbs those medications," says pharmacy doctor and the VP of Pharmacy and Medical Operations at Eden, Dr. Rebecca Emch. "This doesn't mean calcium is 'bad,' but the timing matters. Even something as simple as a morning calcium supplement could unintentionally reduce the effectiveness of a thyroid medication if taken together."

Good to know! Stay safe.